1384 lines
No EOL
50 KiB
C#
1384 lines
No EOL
50 KiB
C#
using System;
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using System.Diagnostics;
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using u32 = System.UInt32;
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using u8 = System.Byte;
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namespace Community.CsharpSqlite
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{
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public partial class Sqlite3
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{
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/*
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**
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** The author disclaims copyright to this source code. In place of
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** a legal notice, here is a blessing:
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**
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** May you do good and not evil.
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** May you find forgiveness for yourself and forgive others.
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** May you share freely, never taking more than you give.
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**
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*************************************************************************
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** This file contains code used by the compiler to add foreign key
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** support to compiled SQL statements.
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*************************************************************************
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** Included in SQLite3 port to C#-SQLite; 2008 Noah B Hart
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** C#-SQLite is an independent reimplementation of the SQLite software library
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**
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** SQLITE_SOURCE_ID: 2011-06-23 19:49:22 4374b7e83ea0a3fbc3691f9c0c936272862f32f2
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**
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************************************************************************* */
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//#include "sqliteInt.h"
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#if !SQLITE_OMIT_FOREIGN_KEY
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#if !SQLITE_OMIT_TRIGGER
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/*
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** Deferred and Immediate FKs
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** --------------------------
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**
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** Foreign keys in SQLite come in two flavours: deferred and immediate.
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** If an immediate foreign key constraint is violated, SQLITE_CONSTRAINT
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** is returned and the current statement transaction rolled back. If a
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** deferred foreign key constraint is violated, no action is taken
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** immediately. However if the application attempts to commit the
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** transaction before fixing the constraint violation, the attempt fails.
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**
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** Deferred constraints are implemented using a simple counter associated
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** with the database handle. The counter is set to zero each time a
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** database transaction is opened. Each time a statement is executed
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** that causes a foreign key violation, the counter is incremented. Each
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** time a statement is executed that removes an existing violation from
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** the database, the counter is decremented. When the transaction is
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** committed, the commit fails if the current value of the counter is
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** greater than zero. This scheme has two big drawbacks:
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**
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** * When a commit fails due to a deferred foreign key constraint,
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** there is no way to tell which foreign constraint is not satisfied,
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** or which row it is not satisfied for.
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**
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** * If the database contains foreign key violations when the
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** transaction is opened, this may cause the mechanism to malfunction.
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**
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** Despite these problems, this approach is adopted as it seems simpler
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** than the alternatives.
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**
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** INSERT operations:
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**
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** I.1) For each FK for which the table is the child table, search
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** the parent table for a match. If none is found increment the
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** constraint counter.
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**
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** I.2) For each FK for which the table is the parent table,
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** search the child table for rows that correspond to the new
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** row in the parent table. Decrement the counter for each row
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** found (as the constraint is now satisfied).
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**
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** DELETE operations:
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**
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** D.1) For each FK for which the table is the child table,
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** search the parent table for a row that corresponds to the
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** deleted row in the child table. If such a row is not found,
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** decrement the counter.
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**
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** D.2) For each FK for which the table is the parent table, search
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** the child table for rows that correspond to the deleted row
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** in the parent table. For each found increment the counter.
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**
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** UPDATE operations:
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**
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** An UPDATE command requires that all 4 steps above are taken, but only
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** for FK constraints for which the affected columns are actually
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** modified (values must be compared at runtime).
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**
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** Note that I.1 and D.1 are very similar operations, as are I.2 and D.2.
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** This simplifies the implementation a bit.
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**
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** For the purposes of immediate FK constraints, the OR REPLACE conflict
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** resolution is considered to delete rows before the new row is inserted.
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** If a delete caused by OR REPLACE violates an FK constraint, an exception
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** is thrown, even if the FK constraint would be satisfied after the new
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** row is inserted.
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**
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** Immediate constraints are usually handled similarly. The only difference
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** is that the counter used is stored as part of each individual statement
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** object (struct Vdbe). If, after the statement has run, its immediate
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** constraint counter is greater than zero, it returns SQLITE_CONSTRAINT
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** and the statement transaction is rolled back. An exception is an INSERT
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** statement that inserts a single row only (no triggers). In this case,
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** instead of using a counter, an exception is thrown immediately if the
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** INSERT violates a foreign key constraint. This is necessary as such
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** an INSERT does not open a statement transaction.
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**
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** TODO: How should dropping a table be handled? How should renaming a
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** table be handled?
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**
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**
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** Query API Notes
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** ---------------
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**
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** Before coding an UPDATE or DELETE row operation, the code-generator
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** for those two operations needs to know whether or not the operation
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** requires any FK processing and, if so, which columns of the original
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** row are required by the FK processing VDBE code (i.e. if FKs were
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** implemented using triggers, which of the old.* columns would be
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** accessed). No information is required by the code-generator before
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** coding an INSERT operation. The functions used by the UPDATE/DELETE
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** generation code to query for this information are:
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**
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** sqlite3FkRequired() - Test to see if FK processing is required.
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** sqlite3FkOldmask() - Query for the set of required old.* columns.
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**
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**
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** Externally accessible module functions
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** --------------------------------------
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**
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** sqlite3FkCheck() - Check for foreign key violations.
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** sqlite3FkActions() - Code triggers for ON UPDATE/ON DELETE actions.
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** sqlite3FkDelete() - Delete an FKey structure.
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*/
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/*
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** VDBE Calling Convention
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** -----------------------
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**
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** Example:
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**
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** For the following INSERT statement:
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**
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** CREATE TABLE t1(a, b INTEGER PRIMARY KEY, c);
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** INSERT INTO t1 VALUES(1, 2, 3.1);
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**
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** Register (x): 2 (type integer)
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** Register (x+1): 1 (type integer)
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** Register (x+2): NULL (type NULL)
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** Register (x+3): 3.1 (type real)
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*/
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/*
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** A foreign key constraint requires that the key columns in the parent
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** table are collectively subject to a UNIQUE or PRIMARY KEY constraint.
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** Given that pParent is the parent table for foreign key constraint pFKey,
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** search the schema a unique index on the parent key columns.
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**
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** If successful, zero is returned. If the parent key is an INTEGER PRIMARY
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** KEY column, then output variable *ppIdx is set to NULL. Otherwise, *ppIdx
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** is set to point to the unique index.
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**
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** If the parent key consists of a single column (the foreign key constraint
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** is not a composite foreign key), refput variable *paiCol is set to NULL.
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** Otherwise, it is set to point to an allocated array of size N, where
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** N is the number of columns in the parent key. The first element of the
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** array is the index of the child table column that is mapped by the FK
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** constraint to the parent table column stored in the left-most column
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** of index *ppIdx. The second element of the array is the index of the
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** child table column that corresponds to the second left-most column of
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** *ppIdx, and so on.
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**
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** If the required index cannot be found, either because:
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**
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** 1) The named parent key columns do not exist, or
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**
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** 2) The named parent key columns do exist, but are not subject to a
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** UNIQUE or PRIMARY KEY constraint, or
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**
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** 3) No parent key columns were provided explicitly as part of the
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** foreign key definition, and the parent table does not have a
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** PRIMARY KEY, or
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**
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** 4) No parent key columns were provided explicitly as part of the
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** foreign key definition, and the PRIMARY KEY of the parent table
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** consists of a different number of columns to the child key in
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** the child table.
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**
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** then non-zero is returned, and a "foreign key mismatch" error loaded
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** into pParse. If an OOM error occurs, non-zero is returned and the
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** pParse.db.mallocFailed flag is set.
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*/
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private static int locateFkeyIndex(
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Parse pParse, /* Parse context to store any error in */
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Table pParent, /* Parent table of FK constraint pFKey */
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FKey pFKey, /* Foreign key to find index for */
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out Index ppIdx, /* OUT: Unique index on parent table */
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out int[] paiCol /* OUT: Map of index columns in pFKey */
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)
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{
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Index pIdx = null; /* Value to return via *ppIdx */
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ppIdx = null;
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int[] aiCol = null; /* Value to return via *paiCol */
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paiCol = null;
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int nCol = pFKey.nCol; /* Number of columns in parent key */
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string zKey = pFKey.aCol[0].zCol; /* Name of left-most parent key column */
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/* The caller is responsible for zeroing output parameters. */
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//assert( ppIdx && *ppIdx==0 );
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//assert( !paiCol || *paiCol==0 );
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Debug.Assert(pParse != null);
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/* If this is a non-composite (single column) foreign key, check if it
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** maps to the INTEGER PRIMARY KEY of table pParent. If so, leave *ppIdx
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** and *paiCol set to zero and return early.
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**
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** Otherwise, for a composite foreign key (more than one column), allocate
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** space for the aiCol array (returned via output parameter *paiCol).
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** Non-composite foreign keys do not require the aiCol array.
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*/
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if (nCol == 1)
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{
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/* The FK maps to the IPK if any of the following are true:
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**
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** 1) There is an INTEGER PRIMARY KEY column and the FK is implicitly
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** mapped to the primary key of table pParent, or
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** 2) The FK is explicitly mapped to a column declared as INTEGER
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** PRIMARY KEY.
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*/
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if (pParent.iPKey >= 0)
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{
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if (null == zKey)
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return 0;
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if (pParent.aCol[pParent.iPKey].zName.Equals(zKey, StringComparison.OrdinalIgnoreCase))
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return 0;
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}
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}
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else //if( paiCol ){
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{
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Debug.Assert(nCol > 1);
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aiCol = new int[nCol];// (int*)sqlite3DbMallocRaw( pParse.db, nCol * sizeof( int ) );
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//if( !aiCol ) return 1;
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paiCol = aiCol;
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}
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for (pIdx = pParent.pIndex; pIdx != null; pIdx = pIdx.pNext)
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{
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if (pIdx.nColumn == nCol && pIdx.onError != OE_None)
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{
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/* pIdx is a UNIQUE index (or a PRIMARY KEY) and has the right number
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** of columns. If each indexed column corresponds to a foreign key
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** column of pFKey, then this index is a winner. */
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if (zKey == null)
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{
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/* If zKey is NULL, then this foreign key is implicitly mapped to
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** the PRIMARY KEY of table pParent. The PRIMARY KEY index may be
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** identified by the test (Index.autoIndex==2). */
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if (pIdx.autoIndex == 2)
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{
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if (aiCol != null)
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{
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int i;
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for (i = 0; i < nCol; i++)
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aiCol[i] = pFKey.aCol[i].iFrom;
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}
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break;
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}
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}
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else
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{
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/* If zKey is non-NULL, then this foreign key was declared to
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** map to an explicit list of columns in table pParent. Check if this
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** index matches those columns. Also, check that the index uses
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** the default collation sequences for each column. */
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int i, j;
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for (i = 0; i < nCol; i++)
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{
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int iCol = pIdx.aiColumn[i]; /* Index of column in parent tbl */
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string zDfltColl; /* Def. collation for column */
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string zIdxCol; /* Name of indexed column */
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/* If the index uses a collation sequence that is different from
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** the default collation sequence for the column, this index is
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** unusable. Bail out early in this case. */
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zDfltColl = pParent.aCol[iCol].zColl;
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if (String.IsNullOrEmpty(zDfltColl))
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{
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zDfltColl = "BINARY";
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}
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if (!pIdx.azColl[i].Equals(zDfltColl, StringComparison.OrdinalIgnoreCase))
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break;
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zIdxCol = pParent.aCol[iCol].zName;
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for (j = 0; j < nCol; j++)
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{
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if (pFKey.aCol[j].zCol.Equals(zIdxCol, StringComparison.OrdinalIgnoreCase))
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{
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if (aiCol != null)
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aiCol[i] = pFKey.aCol[j].iFrom;
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break;
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}
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}
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if (j == nCol)
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break;
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}
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if (i == nCol)
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break; /* pIdx is usable */
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}
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}
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}
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if (null == pIdx)
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{
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if (0 == pParse.disableTriggers)
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{
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sqlite3ErrorMsg(pParse, "foreign key mismatch");
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}
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sqlite3DbFree(pParse.db, ref aiCol);
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return 1;
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}
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ppIdx = pIdx;
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return 0;
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}
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/*
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** This function is called when a row is inserted into or deleted from the
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** child table of foreign key constraint pFKey. If an SQL UPDATE is executed
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** on the child table of pFKey, this function is invoked twice for each row
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** affected - once to "delete" the old row, and then again to "insert" the
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** new row.
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**
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** Each time it is called, this function generates VDBE code to locate the
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** row in the parent table that corresponds to the row being inserted into
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** or deleted from the child table. If the parent row can be found, no
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** special action is taken. Otherwise, if the parent row can *not* be
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** found in the parent table:
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**
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** Operation | FK type | Action taken
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** --------------------------------------------------------------------------
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** INSERT immediate Increment the "immediate constraint counter".
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**
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** DELETE immediate Decrement the "immediate constraint counter".
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**
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** INSERT deferred Increment the "deferred constraint counter".
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**
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** DELETE deferred Decrement the "deferred constraint counter".
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**
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** These operations are identified in the comment at the top of this file
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** (fkey.c) as "I.1" and "D.1".
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*/
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private static void fkLookupParent(
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Parse pParse, /* Parse context */
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int iDb, /* Index of database housing pTab */
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Table pTab, /* Parent table of FK pFKey */
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Index pIdx, /* Unique index on parent key columns in pTab */
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FKey pFKey, /* Foreign key constraint */
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int[] aiCol, /* Map from parent key columns to child table columns */
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int regData, /* Address of array containing child table row */
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int nIncr, /* Increment constraint counter by this */
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int isIgnore /* If true, pretend pTab contains all NULL values */
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)
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{
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int i; /* Iterator variable */
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Vdbe v = sqlite3GetVdbe(pParse); /* Vdbe to add code to */
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int iCur = pParse.nTab - 1; /* Cursor number to use */
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int iOk = sqlite3VdbeMakeLabel(v); /* jump here if parent key found */
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/* If nIncr is less than zero, then check at runtime if there are any
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** outstanding constraints to resolve. If there are not, there is no need
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** to check if deleting this row resolves any outstanding violations.
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**
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** Check if any of the key columns in the child table row are NULL. If
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** any are, then the constraint is considered satisfied. No need to
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** search for a matching row in the parent table. */
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if (nIncr < 0)
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{
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sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey.isDeferred, iOk);
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}
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for (i = 0; i < pFKey.nCol; i++)
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{
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int iReg = aiCol[i] + regData + 1;
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sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iOk);
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}
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if (isIgnore == 0)
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{
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if (pIdx == null)
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{
|
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/* If pIdx is NULL, then the parent key is the INTEGER PRIMARY KEY
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** column of the parent table (table pTab). */
|
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int iMustBeInt; /* Address of MustBeInt instruction */
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int regTemp = sqlite3GetTempReg(pParse);
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/* Invoke MustBeInt to coerce the child key value to an integer (i.e.
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** apply the affinity of the parent key). If this fails, then there
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** is no matching parent key. Before using MustBeInt, make a copy of
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** the value. Otherwise, the value inserted into the child key column
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** will have INTEGER affinity applied to it, which may not be correct. */
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sqlite3VdbeAddOp2(v, OP_SCopy, aiCol[0] + 1 + regData, regTemp);
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iMustBeInt = sqlite3VdbeAddOp2(v, OP_MustBeInt, regTemp, 0);
|
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|
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/* If the parent table is the same as the child table, and we are about
|
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** to increment the constraint-counter (i.e. this is an INSERT operation),
|
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** then check if the row being inserted matches itself. If so, do not
|
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** increment the constraint-counter. */
|
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if (pTab == pFKey.pFrom && nIncr == 1)
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{
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sqlite3VdbeAddOp3(v, OP_Eq, regData, iOk, regTemp);
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}
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sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
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sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regTemp);
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sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk);
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sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v) - 2);
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sqlite3VdbeJumpHere(v, iMustBeInt);
|
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sqlite3ReleaseTempReg(pParse, regTemp);
|
|
}
|
|
else
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{
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int nCol = pFKey.nCol;
|
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int regTemp = sqlite3GetTempRange(pParse, nCol);
|
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int regRec = sqlite3GetTempReg(pParse);
|
|
KeyInfo pKey = sqlite3IndexKeyinfo(pParse, pIdx);
|
|
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sqlite3VdbeAddOp3(v, OP_OpenRead, iCur, pIdx.tnum, iDb);
|
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sqlite3VdbeChangeP4(v, -1, pKey, P4_KEYINFO_HANDOFF);
|
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for (i = 0; i < nCol; i++)
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{
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sqlite3VdbeAddOp2(v, OP_Copy, aiCol[i] + 1 + regData, regTemp + i);
|
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}
|
|
|
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/* If the parent table is the same as the child table, and we are about
|
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** to increment the constraint-counter (i.e. this is an INSERT operation),
|
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** then check if the row being inserted matches itself. If so, do not
|
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** increment the constraint-counter.
|
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**
|
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** If any of the parent-key values are NULL, then the row cannot match
|
|
** itself. So set JUMPIFNULL to make sure we do the OP_Found if any
|
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** of the parent-key values are NULL (at this point it is known that
|
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** none of the child key values are).
|
|
*/
|
|
if (pTab == pFKey.pFrom && nIncr == 1)
|
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{
|
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int iJump = sqlite3VdbeCurrentAddr(v) + nCol + 1;
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for (i = 0; i < nCol; i++)
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{
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int iChild = aiCol[i] + 1 + regData;
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int iParent = pIdx.aiColumn[i] + 1 + regData;
|
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Debug.Assert(aiCol[i] != pTab.iPKey);
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if (pIdx.aiColumn[i] == pTab.iPKey)
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{
|
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/* The parent key is a composite key that includes the IPK column */
|
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iParent = regData;
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}
|
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sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent);
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sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
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|
}
|
|
sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk);
|
|
}
|
|
|
|
sqlite3VdbeAddOp3(v, OP_MakeRecord, regTemp, nCol, regRec);
|
|
sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), P4_TRANSIENT);
|
|
sqlite3VdbeAddOp4Int(v, OP_Found, iCur, iOk, regRec, 0);
|
|
|
|
sqlite3ReleaseTempReg(pParse, regRec);
|
|
sqlite3ReleaseTempRange(pParse, regTemp, nCol);
|
|
}
|
|
}
|
|
|
|
if (0 == pFKey.isDeferred && null == pParse.pToplevel && 0 == pParse.isMultiWrite)
|
|
{
|
|
/* Special case: If this is an INSERT statement that will insert exactly
|
|
** one row into the table, raise a constraint immediately instead of
|
|
** incrementing a counter. This is necessary as the VM code is being
|
|
** generated for will not open a statement transaction. */
|
|
Debug.Assert(nIncr == 1);
|
|
sqlite3HaltConstraint(
|
|
pParse, OE_Abort, "foreign key constraint failed", P4_STATIC
|
|
);
|
|
}
|
|
else
|
|
{
|
|
if (nIncr > 0 && pFKey.isDeferred == 0)
|
|
{
|
|
sqlite3ParseToplevel(pParse).mayAbort = 1;
|
|
}
|
|
sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey.isDeferred, nIncr);
|
|
}
|
|
|
|
sqlite3VdbeResolveLabel(v, iOk);
|
|
sqlite3VdbeAddOp1(v, OP_Close, iCur);
|
|
}
|
|
|
|
/*
|
|
** This function is called to generate code executed when a row is deleted
|
|
** from the parent table of foreign key constraint pFKey and, if pFKey is
|
|
** deferred, when a row is inserted into the same table. When generating
|
|
** code for an SQL UPDATE operation, this function may be called twice -
|
|
** once to "delete" the old row and once to "insert" the new row.
|
|
**
|
|
** The code generated by this function scans through the rows in the child
|
|
** table that correspond to the parent table row being deleted or inserted.
|
|
** For each child row found, one of the following actions is taken:
|
|
**
|
|
** Operation | FK type | Action taken
|
|
** --------------------------------------------------------------------------
|
|
** DELETE immediate Increment the "immediate constraint counter".
|
|
** Or, if the ON (UPDATE|DELETE) action is RESTRICT,
|
|
** throw a "foreign key constraint failed" exception.
|
|
**
|
|
** INSERT immediate Decrement the "immediate constraint counter".
|
|
**
|
|
** DELETE deferred Increment the "deferred constraint counter".
|
|
** Or, if the ON (UPDATE|DELETE) action is RESTRICT,
|
|
** throw a "foreign key constraint failed" exception.
|
|
**
|
|
** INSERT deferred Decrement the "deferred constraint counter".
|
|
**
|
|
** These operations are identified in the comment at the top of this file
|
|
** (fkey.c) as "I.2" and "D.2".
|
|
*/
|
|
|
|
private static void fkScanChildren(
|
|
Parse pParse, /* Parse context */
|
|
SrcList pSrc, /* SrcList containing the table to scan */
|
|
Table pTab,
|
|
Index pIdx, /* Foreign key index */
|
|
FKey pFKey, /* Foreign key relationship */
|
|
int[] aiCol, /* Map from pIdx cols to child table cols */
|
|
int regData, /* Referenced table data starts here */
|
|
int nIncr /* Amount to increment deferred counter by */
|
|
)
|
|
{
|
|
sqlite3 db = pParse.db; /* Database handle */
|
|
int i; /* Iterator variable */
|
|
Expr pWhere = null; /* WHERE clause to scan with */
|
|
NameContext sNameContext; /* Context used to resolve WHERE clause */
|
|
WhereInfo pWInfo; /* Context used by sqlite3WhereXXX() */
|
|
int iFkIfZero = 0; /* Address of OP_FkIfZero */
|
|
Vdbe v = sqlite3GetVdbe(pParse);
|
|
|
|
Debug.Assert(null == pIdx || pIdx.pTable == pTab);
|
|
|
|
if (nIncr < 0)
|
|
{
|
|
iFkIfZero = sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey.isDeferred, 0);
|
|
}
|
|
|
|
/* Create an Expr object representing an SQL expression like:
|
|
**
|
|
** <parent-key1> = <child-key1> AND <parent-key2> = <child-key2> ...
|
|
**
|
|
** The collation sequence used for the comparison should be that of
|
|
** the parent key columns. The affinity of the parent key column should
|
|
** be applied to each child key value before the comparison takes place.
|
|
*/
|
|
for (i = 0; i < pFKey.nCol; i++)
|
|
{
|
|
Expr pLeft; /* Value from parent table row */
|
|
Expr pRight; /* Column ref to child table */
|
|
Expr pEq; /* Expression (pLeft = pRight) */
|
|
int iCol; /* Index of column in child table */
|
|
string zCol; /* Name of column in child table */
|
|
|
|
pLeft = sqlite3Expr(db, TK_REGISTER, null);
|
|
if (pLeft != null)
|
|
{
|
|
/* Set the collation sequence and affinity of the LHS of each TK_EQ
|
|
** expression to the parent key column defaults. */
|
|
if (pIdx != null)
|
|
{
|
|
Column pCol;
|
|
iCol = pIdx.aiColumn[i];
|
|
pCol = pTab.aCol[iCol];
|
|
if (pTab.iPKey == iCol)
|
|
iCol = -1;
|
|
pLeft.iTable = regData + iCol + 1;
|
|
pLeft.affinity = pCol.affinity;
|
|
pLeft.pColl = sqlite3LocateCollSeq(pParse, pCol.zColl);
|
|
}
|
|
else
|
|
{
|
|
pLeft.iTable = regData;
|
|
pLeft.affinity = SQLITE_AFF_INTEGER;
|
|
}
|
|
}
|
|
iCol = aiCol != null ? aiCol[i] : pFKey.aCol[0].iFrom;
|
|
Debug.Assert(iCol >= 0);
|
|
zCol = pFKey.pFrom.aCol[iCol].zName;
|
|
pRight = sqlite3Expr(db, TK_ID, zCol);
|
|
pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight, 0);
|
|
pWhere = sqlite3ExprAnd(db, pWhere, pEq);
|
|
}
|
|
|
|
/* If the child table is the same as the parent table, and this scan
|
|
** is taking place as part of a DELETE operation (operation D.2), omit the
|
|
** row being deleted from the scan by adding ($rowid != rowid) to the WHERE
|
|
** clause, where $rowid is the rowid of the row being deleted. */
|
|
if (pTab == pFKey.pFrom && nIncr > 0)
|
|
{
|
|
Expr pEq; /* Expression (pLeft = pRight) */
|
|
Expr pLeft; /* Value from parent table row */
|
|
Expr pRight; /* Column ref to child table */
|
|
pLeft = sqlite3Expr(db, TK_REGISTER, null);
|
|
pRight = sqlite3Expr(db, TK_COLUMN, null);
|
|
if (pLeft != null && pRight != null)
|
|
{
|
|
pLeft.iTable = regData;
|
|
pLeft.affinity = SQLITE_AFF_INTEGER;
|
|
pRight.iTable = pSrc.a[0].iCursor;
|
|
pRight.iColumn = -1;
|
|
}
|
|
pEq = sqlite3PExpr(pParse, TK_NE, pLeft, pRight, 0);
|
|
pWhere = sqlite3ExprAnd(db, pWhere, pEq);
|
|
}
|
|
|
|
/* Resolve the references in the WHERE clause. */
|
|
sNameContext = new NameContext();// memset( &sNameContext, 0, sizeof( NameContext ) );
|
|
sNameContext.pSrcList = pSrc;
|
|
sNameContext.pParse = pParse;
|
|
sqlite3ResolveExprNames(sNameContext, ref pWhere);
|
|
|
|
/* Create VDBE to loop through the entries in pSrc that match the WHERE
|
|
** clause. If the constraint is not deferred, throw an exception for
|
|
** each row found. Otherwise, for deferred constraints, increment the
|
|
** deferred constraint counter by nIncr for each row selected. */
|
|
ExprList elDummy = null;
|
|
pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, ref elDummy, 0);
|
|
if (nIncr > 0 && pFKey.isDeferred == 0)
|
|
{
|
|
sqlite3ParseToplevel(pParse).mayAbort = 1;
|
|
}
|
|
sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey.isDeferred, nIncr);
|
|
if (pWInfo != null)
|
|
{
|
|
sqlite3WhereEnd(pWInfo);
|
|
}
|
|
|
|
/* Clean up the WHERE clause constructed above. */
|
|
sqlite3ExprDelete(db, ref pWhere);
|
|
if (iFkIfZero != 0)
|
|
{
|
|
sqlite3VdbeJumpHere(v, iFkIfZero);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This function returns a pointer to the head of a linked list of FK
|
|
** constraints for which table pTab is the parent table. For example,
|
|
** given the following schema:
|
|
**
|
|
** CREATE TABLE t1(a PRIMARY KEY);
|
|
** CREATE TABLE t2(b REFERENCES t1(a);
|
|
**
|
|
** Calling this function with table "t1" as an argument returns a pointer
|
|
** to the FKey structure representing the foreign key constraint on table
|
|
** "t2". Calling this function with "t2" as the argument would return a
|
|
** NULL pointer (as there are no FK constraints for which t2 is the parent
|
|
** table).
|
|
*/
|
|
|
|
private static FKey sqlite3FkReferences(Table pTab)
|
|
{
|
|
int nName = sqlite3Strlen30(pTab.zName);
|
|
return sqlite3HashFind(pTab.pSchema.fkeyHash, pTab.zName, nName, (FKey)null);
|
|
}
|
|
|
|
/*
|
|
** The second argument is a Trigger structure allocated by the
|
|
** fkActionTrigger() routine. This function deletes the Trigger structure
|
|
** and all of its sub-components.
|
|
**
|
|
** The Trigger structure or any of its sub-components may be allocated from
|
|
** the lookaside buffer belonging to database handle dbMem.
|
|
*/
|
|
|
|
private static void fkTriggerDelete(sqlite3 dbMem, Trigger p)
|
|
{
|
|
if (p != null)
|
|
{
|
|
TriggerStep pStep = p.step_list;
|
|
sqlite3ExprDelete(dbMem, ref pStep.pWhere);
|
|
sqlite3ExprListDelete(dbMem, ref pStep.pExprList);
|
|
sqlite3SelectDelete(dbMem, ref pStep.pSelect);
|
|
sqlite3ExprDelete(dbMem, ref p.pWhen);
|
|
sqlite3DbFree(dbMem, ref p);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This function is called to generate code that runs when table pTab is
|
|
** being dropped from the database. The SrcList passed as the second argument
|
|
** to this function contains a single entry guaranteed to resolve to
|
|
** table pTab.
|
|
**
|
|
** Normally, no code is required. However, if either
|
|
**
|
|
** (a) The table is the parent table of a FK constraint, or
|
|
** (b) The table is the child table of a deferred FK constraint and it is
|
|
** determined at runtime that there are outstanding deferred FK
|
|
** constraint violations in the database,
|
|
**
|
|
** then the equivalent of "DELETE FROM <tbl>" is executed before dropping
|
|
** the table from the database. Triggers are disabled while running this
|
|
** DELETE, but foreign key actions are not.
|
|
*/
|
|
|
|
private static void sqlite3FkDropTable(Parse pParse, SrcList pName, Table pTab)
|
|
{
|
|
sqlite3 db = pParse.db;
|
|
if ((db.flags & SQLITE_ForeignKeys) != 0 && !IsVirtual(pTab) && null == pTab.pSelect)
|
|
{
|
|
int iSkip = 0;
|
|
Vdbe v = sqlite3GetVdbe(pParse);
|
|
|
|
Debug.Assert(v != null); /* VDBE has already been allocated */
|
|
if (sqlite3FkReferences(pTab) == null)
|
|
{
|
|
/* Search for a deferred foreign key constraint for which this table
|
|
** is the child table. If one cannot be found, return without
|
|
** generating any VDBE code. If one can be found, then jump over
|
|
** the entire DELETE if there are no outstanding deferred constraints
|
|
** when this statement is run. */
|
|
FKey p;
|
|
for (p = pTab.pFKey; p != null; p = p.pNextFrom)
|
|
{
|
|
if (p.isDeferred != 0)
|
|
break;
|
|
}
|
|
if (null == p)
|
|
return;
|
|
iSkip = sqlite3VdbeMakeLabel(v);
|
|
sqlite3VdbeAddOp2(v, OP_FkIfZero, 1, iSkip);
|
|
}
|
|
|
|
pParse.disableTriggers = 1;
|
|
sqlite3DeleteFrom(pParse, sqlite3SrcListDup(db, pName, 0), null);
|
|
pParse.disableTriggers = 0;
|
|
|
|
/* If the DELETE has generated immediate foreign key constraint
|
|
** violations, halt the VDBE and return an error at this point, before
|
|
** any modifications to the schema are made. This is because statement
|
|
** transactions are not able to rollback schema changes. */
|
|
sqlite3VdbeAddOp2(v, OP_FkIfZero, 0, sqlite3VdbeCurrentAddr(v) + 2);
|
|
sqlite3HaltConstraint(
|
|
pParse, OE_Abort, "foreign key constraint failed", P4_STATIC
|
|
);
|
|
|
|
if (iSkip != 0)
|
|
{
|
|
sqlite3VdbeResolveLabel(v, iSkip);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This function is called when inserting, deleting or updating a row of
|
|
** table pTab to generate VDBE code to perform foreign key constraint
|
|
** processing for the operation.
|
|
**
|
|
** For a DELETE operation, parameter regOld is passed the index of the
|
|
** first register in an array of (pTab.nCol+1) registers containing the
|
|
** rowid of the row being deleted, followed by each of the column values
|
|
** of the row being deleted, from left to right. Parameter regNew is passed
|
|
** zero in this case.
|
|
**
|
|
** For an INSERT operation, regOld is passed zero and regNew is passed the
|
|
** first register of an array of (pTab.nCol+1) registers containing the new
|
|
** row data.
|
|
**
|
|
** For an UPDATE operation, this function is called twice. Once before
|
|
** the original record is deleted from the table using the calling convention
|
|
** described for DELETE. Then again after the original record is deleted
|
|
** but before the new record is inserted using the INSERT convention.
|
|
*/
|
|
|
|
private static void sqlite3FkCheck(
|
|
Parse pParse, /* Parse context */
|
|
Table pTab, /* Row is being deleted from this table */
|
|
int regOld, /* Previous row data is stored here */
|
|
int regNew /* New row data is stored here */
|
|
)
|
|
{
|
|
sqlite3 db = pParse.db; /* Database handle */
|
|
FKey pFKey; /* Used to iterate through FKs */
|
|
int iDb; /* Index of database containing pTab */
|
|
string zDb; /* Name of database containing pTab */
|
|
int isIgnoreErrors = pParse.disableTriggers;
|
|
|
|
/* Exactly one of regOld and regNew should be non-zero. */
|
|
Debug.Assert((regOld == 0) != (regNew == 0));
|
|
|
|
/* If foreign-keys are disabled, this function is a no-op. */
|
|
if ((db.flags & SQLITE_ForeignKeys) == 0)
|
|
return;
|
|
|
|
iDb = sqlite3SchemaToIndex(db, pTab.pSchema);
|
|
zDb = db.aDb[iDb].zName;
|
|
|
|
/* Loop through all the foreign key constraints for which pTab is the
|
|
** child table (the table that the foreign key definition is part of). */
|
|
for (pFKey = pTab.pFKey; pFKey != null; pFKey = pFKey.pNextFrom)
|
|
{
|
|
Table pTo; /* Parent table of foreign key pFKey */
|
|
Index pIdx = null; /* Index on key columns in pTo */
|
|
int[] aiFree = null;
|
|
int[] aiCol;
|
|
int iCol;
|
|
int i;
|
|
int isIgnore = 0;
|
|
|
|
/* Find the parent table of this foreign key. Also find a unique index
|
|
** on the parent key columns in the parent table. If either of these
|
|
** schema items cannot be located, set an error in pParse and return
|
|
** early. */
|
|
if (pParse.disableTriggers != 0)
|
|
{
|
|
pTo = sqlite3FindTable(db, pFKey.zTo, zDb);
|
|
}
|
|
else
|
|
{
|
|
pTo = sqlite3LocateTable(pParse, 0, pFKey.zTo, zDb);
|
|
}
|
|
if (null == pTo || locateFkeyIndex(pParse, pTo, pFKey, out pIdx, out aiFree) != 0)
|
|
{
|
|
if (0 == isIgnoreErrors /* || db.mallocFailed */)
|
|
return;
|
|
continue;
|
|
}
|
|
Debug.Assert(pFKey.nCol == 1 || (aiFree != null && pIdx != null));
|
|
|
|
if (aiFree != null)
|
|
{
|
|
aiCol = aiFree;
|
|
}
|
|
else
|
|
{
|
|
iCol = pFKey.aCol[0].iFrom;
|
|
aiCol = new int[1];
|
|
aiCol[0] = iCol;
|
|
}
|
|
for (i = 0; i < pFKey.nCol; i++)
|
|
{
|
|
if (aiCol[i] == pTab.iPKey)
|
|
{
|
|
aiCol[i] = -1;
|
|
}
|
|
#if !SQLITE_OMIT_AUTHORIZATION
|
|
/* Request permission to read the parent key columns. If the
|
|
** authorization callback returns SQLITE_IGNORE, behave as if any
|
|
** values read from the parent table are NULL. */
|
|
if( db.xAuth ){
|
|
int rcauth;
|
|
char *zCol = pTo.aCol[pIdx ? pIdx.aiColumn[i] : pTo.iPKey].zName;
|
|
rcauth = sqlite3AuthReadCol(pParse, pTo.zName, zCol, iDb);
|
|
isIgnore = (rcauth==SQLITE_IGNORE);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/* Take a shared-cache advisory read-lock on the parent table. Allocate
|
|
** a cursor to use to search the unique index on the parent key columns
|
|
** in the parent table. */
|
|
sqlite3TableLock(pParse, iDb, pTo.tnum, 0, pTo.zName);
|
|
pParse.nTab++;
|
|
|
|
if (regOld != 0)
|
|
{
|
|
/* A row is being removed from the child table. Search for the parent.
|
|
** If the parent does not exist, removing the child row resolves an
|
|
** outstanding foreign key constraint violation. */
|
|
fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1, isIgnore);
|
|
}
|
|
if (regNew != 0)
|
|
{
|
|
/* A row is being added to the child table. If a parent row cannot
|
|
** be found, adding the child row has violated the FK constraint. */
|
|
fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regNew, +1, isIgnore);
|
|
}
|
|
|
|
sqlite3DbFree(db, ref aiFree);
|
|
}
|
|
|
|
/* Loop through all the foreign key constraints that refer to this table */
|
|
for (pFKey = sqlite3FkReferences(pTab); pFKey != null; pFKey = pFKey.pNextTo)
|
|
{
|
|
Index pIdx = null; /* Foreign key index for pFKey */
|
|
SrcList pSrc;
|
|
int[] aiCol = null;
|
|
|
|
if (0 == pFKey.isDeferred && null == pParse.pToplevel && 0 == pParse.isMultiWrite)
|
|
{
|
|
Debug.Assert(regOld == 0 && regNew != 0);
|
|
/* Inserting a single row into a parent table cannot cause an immediate
|
|
** foreign key violation. So do nothing in this case. */
|
|
continue;
|
|
}
|
|
|
|
if (locateFkeyIndex(pParse, pTab, pFKey, out pIdx, out aiCol) != 0)
|
|
{
|
|
if (0 == isIgnoreErrors /*|| db.mallocFailed */)
|
|
return;
|
|
continue;
|
|
}
|
|
Debug.Assert(aiCol != null || pFKey.nCol == 1);
|
|
|
|
/* Create a SrcList structure containing a single table (the table
|
|
** the foreign key that refers to this table is attached to). This
|
|
** is required for the sqlite3WhereXXX() interface. */
|
|
pSrc = sqlite3SrcListAppend(db, 0, null, null);
|
|
if (pSrc != null)
|
|
{
|
|
SrcList_item pItem = pSrc.a[0];
|
|
pItem.pTab = pFKey.pFrom;
|
|
pItem.zName = pFKey.pFrom.zName;
|
|
pItem.pTab.nRef++;
|
|
pItem.iCursor = pParse.nTab++;
|
|
|
|
if (regNew != 0)
|
|
{
|
|
fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regNew, -1);
|
|
}
|
|
if (regOld != 0)
|
|
{
|
|
/* If there is a RESTRICT action configured for the current operation
|
|
** on the parent table of this FK, then throw an exception
|
|
** immediately if the FK constraint is violated, even if this is a
|
|
** deferred trigger. That's what RESTRICT means. To defer checking
|
|
** the constraint, the FK should specify NO ACTION (represented
|
|
** using OE_None). NO ACTION is the default. */
|
|
fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regOld, 1);
|
|
}
|
|
pItem.zName = null;
|
|
sqlite3SrcListDelete(db, ref pSrc);
|
|
}
|
|
sqlite3DbFree(db, ref aiCol);
|
|
}
|
|
}
|
|
|
|
//#define COLUMN_MASK(x) (((x)>31) ? 0xffffffff : ((u32)1<<(x)))
|
|
private static uint COLUMN_MASK(int x)
|
|
{
|
|
return ((x) > 31) ? 0xffffffff : ((u32)1 << (x));
|
|
}
|
|
|
|
/*
|
|
** This function is called before generating code to update or delete a
|
|
** row contained in table pTab.
|
|
*/
|
|
|
|
private static u32 sqlite3FkOldmask(
|
|
Parse pParse, /* Parse context */
|
|
Table pTab /* Table being modified */
|
|
)
|
|
{
|
|
u32 mask = 0;
|
|
if ((pParse.db.flags & SQLITE_ForeignKeys) != 0)
|
|
{
|
|
FKey p;
|
|
int i;
|
|
for (p = pTab.pFKey; p != null; p = p.pNextFrom)
|
|
{
|
|
for (i = 0; i < p.nCol; i++)
|
|
mask |= COLUMN_MASK(p.aCol[i].iFrom);
|
|
}
|
|
for (p = sqlite3FkReferences(pTab); p != null; p = p.pNextTo)
|
|
{
|
|
Index pIdx;
|
|
int[] iDummy;
|
|
locateFkeyIndex(pParse, pTab, p, out pIdx, out iDummy);
|
|
if (pIdx != null)
|
|
{
|
|
for (i = 0; i < pIdx.nColumn; i++)
|
|
mask |= COLUMN_MASK(pIdx.aiColumn[i]);
|
|
}
|
|
}
|
|
}
|
|
return mask;
|
|
}
|
|
|
|
/*
|
|
** This function is called before generating code to update or delete a
|
|
** row contained in table pTab. If the operation is a DELETE, then
|
|
** parameter aChange is passed a NULL value. For an UPDATE, aChange points
|
|
** to an array of size N, where N is the number of columns in table pTab.
|
|
** If the i'th column is not modified by the UPDATE, then the corresponding
|
|
** entry in the aChange[] array is set to -1. If the column is modified,
|
|
** the value is 0 or greater. Parameter chngRowid is set to true if the
|
|
** UPDATE statement modifies the rowid fields of the table.
|
|
**
|
|
** If any foreign key processing will be required, this function returns
|
|
** true. If there is no foreign key related processing, this function
|
|
** returns false.
|
|
*/
|
|
|
|
private static int sqlite3FkRequired(
|
|
Parse pParse, /* Parse context */
|
|
Table pTab, /* Table being modified */
|
|
int[] aChange, /* Non-NULL for UPDATE operations */
|
|
int chngRowid /* True for UPDATE that affects rowid */
|
|
)
|
|
{
|
|
if ((pParse.db.flags & SQLITE_ForeignKeys) != 0)
|
|
{
|
|
if (null == aChange)
|
|
{
|
|
/* A DELETE operation. Foreign key processing is required if the
|
|
** table in question is either the child or parent table for any
|
|
** foreign key constraint. */
|
|
return (sqlite3FkReferences(pTab) != null || pTab.pFKey != null) ? 1 : 0;
|
|
}
|
|
else
|
|
{
|
|
/* This is an UPDATE. Foreign key processing is only required if the
|
|
** operation modifies one or more child or parent key columns. */
|
|
int i;
|
|
FKey p;
|
|
|
|
/* Check if any child key columns are being modified. */
|
|
for (p = pTab.pFKey; p != null; p = p.pNextFrom)
|
|
{
|
|
for (i = 0; i < p.nCol; i++)
|
|
{
|
|
int iChildKey = p.aCol[i].iFrom;
|
|
if (aChange[iChildKey] >= 0)
|
|
return 1;
|
|
if (iChildKey == pTab.iPKey && chngRowid != 0)
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
/* Check if any parent key columns are being modified. */
|
|
for (p = sqlite3FkReferences(pTab); p != null; p = p.pNextTo)
|
|
{
|
|
for (i = 0; i < p.nCol; i++)
|
|
{
|
|
string zKey = p.aCol[i].zCol;
|
|
int iKey;
|
|
for (iKey = 0; iKey < pTab.nCol; iKey++)
|
|
{
|
|
Column pCol = pTab.aCol[iKey];
|
|
if ((!String.IsNullOrEmpty(zKey) ? pCol.zName.Equals(zKey, StringComparison.OrdinalIgnoreCase) : pCol.isPrimKey != 0))
|
|
{
|
|
if (aChange[iKey] >= 0)
|
|
return 1;
|
|
if (iKey == pTab.iPKey && chngRowid != 0)
|
|
return 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
** This function is called when an UPDATE or DELETE operation is being
|
|
** compiled on table pTab, which is the parent table of foreign-key pFKey.
|
|
** If the current operation is an UPDATE, then the pChanges parameter is
|
|
** passed a pointer to the list of columns being modified. If it is a
|
|
** DELETE, pChanges is passed a NULL pointer.
|
|
**
|
|
** It returns a pointer to a Trigger structure containing a trigger
|
|
** equivalent to the ON UPDATE or ON DELETE action specified by pFKey.
|
|
** If the action is "NO ACTION" or "RESTRICT", then a NULL pointer is
|
|
** returned (these actions require no special handling by the triggers
|
|
** sub-system, code for them is created by fkScanChildren()).
|
|
**
|
|
** For example, if pFKey is the foreign key and pTab is table "p" in
|
|
** the following schema:
|
|
**
|
|
** CREATE TABLE p(pk PRIMARY KEY);
|
|
** CREATE TABLE c(ck REFERENCES p ON DELETE CASCADE);
|
|
**
|
|
** then the returned trigger structure is equivalent to:
|
|
**
|
|
** CREATE TRIGGER ... DELETE ON p BEGIN
|
|
** DELETE FROM c WHERE ck = old.pk;
|
|
** END;
|
|
**
|
|
** The returned pointer is cached as part of the foreign key object. It
|
|
** is eventually freed along with the rest of the foreign key object by
|
|
** sqlite3FkDelete().
|
|
*/
|
|
|
|
private static Trigger fkActionTrigger(
|
|
Parse pParse, /* Parse context */
|
|
Table pTab, /* Table being updated or deleted from */
|
|
FKey pFKey, /* Foreign key to get action for */
|
|
ExprList pChanges /* Change-list for UPDATE, NULL for DELETE */
|
|
)
|
|
{
|
|
sqlite3 db = pParse.db; /* Database handle */
|
|
int action; /* One of OE_None, OE_Cascade etc. */
|
|
Trigger pTrigger; /* Trigger definition to return */
|
|
int iAction = (pChanges != null) ? 1 : 0; /* 1 for UPDATE, 0 for DELETE */
|
|
|
|
action = pFKey.aAction[iAction];
|
|
pTrigger = pFKey.apTrigger[iAction];
|
|
|
|
if (action != OE_None && null == pTrigger)
|
|
{
|
|
u8 enableLookaside; /* Copy of db.lookaside.bEnabled */
|
|
string zFrom; /* Name of child table */
|
|
int nFrom; /* Length in bytes of zFrom */
|
|
Index pIdx = null; /* Parent key index for this FK */
|
|
int[] aiCol = null; /* child table cols . parent key cols */
|
|
TriggerStep pStep = null; /* First (only) step of trigger program */
|
|
Expr pWhere = null; /* WHERE clause of trigger step */
|
|
ExprList pList = null; /* Changes list if ON UPDATE CASCADE */
|
|
Select pSelect = null; /* If RESTRICT, "SELECT RAISE(...)" */
|
|
int i; /* Iterator variable */
|
|
Expr pWhen = null; /* WHEN clause for the trigger */
|
|
|
|
if (locateFkeyIndex(pParse, pTab, pFKey, out pIdx, out aiCol) != 0)
|
|
return null;
|
|
Debug.Assert(aiCol != null || pFKey.nCol == 1);
|
|
|
|
for (i = 0; i < pFKey.nCol; i++)
|
|
{
|
|
Token tOld = new Token("old", 3); /* Literal "old" token */
|
|
Token tNew = new Token("new", 3); /* Literal "new" token */
|
|
Token tFromCol = new Token(); /* Name of column in child table */
|
|
Token tToCol = new Token(); /* Name of column in parent table */
|
|
int iFromCol; /* Idx of column in child table */
|
|
Expr pEq; /* tFromCol = OLD.tToCol */
|
|
|
|
iFromCol = aiCol != null ? aiCol[i] : pFKey.aCol[0].iFrom;
|
|
Debug.Assert(iFromCol >= 0);
|
|
tToCol.z = pIdx != null ? pTab.aCol[pIdx.aiColumn[i]].zName : "oid";
|
|
tFromCol.z = pFKey.pFrom.aCol[iFromCol].zName;
|
|
|
|
tToCol.n = sqlite3Strlen30(tToCol.z);
|
|
tFromCol.n = sqlite3Strlen30(tFromCol.z);
|
|
|
|
/* Create the expression "OLD.zToCol = zFromCol". It is important
|
|
** that the "OLD.zToCol" term is on the LHS of the = operator, so
|
|
** that the affinity and collation sequence associated with the
|
|
** parent table are used for the comparison. */
|
|
pEq = sqlite3PExpr(pParse, TK_EQ,
|
|
sqlite3PExpr(pParse, TK_DOT,
|
|
sqlite3PExpr(pParse, TK_ID, null, null, tOld),
|
|
sqlite3PExpr(pParse, TK_ID, null, null, tToCol)
|
|
, 0),
|
|
sqlite3PExpr(pParse, TK_ID, null, null, tFromCol)
|
|
, 0);
|
|
pWhere = sqlite3ExprAnd(db, pWhere, pEq);
|
|
|
|
/* For ON UPDATE, construct the next term of the WHEN clause.
|
|
** The final WHEN clause will be like this:
|
|
**
|
|
** WHEN NOT(old.col1 IS new.col1 AND ... AND old.colN IS new.colN)
|
|
*/
|
|
if (pChanges != null)
|
|
{
|
|
pEq = sqlite3PExpr(pParse, TK_IS,
|
|
sqlite3PExpr(pParse, TK_DOT,
|
|
sqlite3PExpr(pParse, TK_ID, null, null, tOld),
|
|
sqlite3PExpr(pParse, TK_ID, null, null, tToCol),
|
|
0),
|
|
sqlite3PExpr(pParse, TK_DOT,
|
|
sqlite3PExpr(pParse, TK_ID, null, null, tNew),
|
|
sqlite3PExpr(pParse, TK_ID, null, null, tToCol),
|
|
0),
|
|
0);
|
|
pWhen = sqlite3ExprAnd(db, pWhen, pEq);
|
|
}
|
|
|
|
if (action != OE_Restrict && (action != OE_Cascade || pChanges != null))
|
|
{
|
|
Expr pNew;
|
|
if (action == OE_Cascade)
|
|
{
|
|
pNew = sqlite3PExpr(pParse, TK_DOT,
|
|
sqlite3PExpr(pParse, TK_ID, null, null, tNew),
|
|
sqlite3PExpr(pParse, TK_ID, null, null, tToCol)
|
|
, 0);
|
|
}
|
|
else if (action == OE_SetDflt)
|
|
{
|
|
Expr pDflt = pFKey.pFrom.aCol[iFromCol].pDflt;
|
|
if (pDflt != null)
|
|
{
|
|
pNew = sqlite3ExprDup(db, pDflt, 0);
|
|
}
|
|
else
|
|
{
|
|
pNew = sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
pNew = sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
|
|
}
|
|
pList = sqlite3ExprListAppend(pParse, pList, pNew);
|
|
sqlite3ExprListSetName(pParse, pList, tFromCol, 0);
|
|
}
|
|
}
|
|
sqlite3DbFree(db, ref aiCol);
|
|
|
|
zFrom = pFKey.pFrom.zName;
|
|
nFrom = sqlite3Strlen30(zFrom);
|
|
|
|
if (action == OE_Restrict)
|
|
{
|
|
Token tFrom = new Token();
|
|
Expr pRaise;
|
|
|
|
tFrom.z = zFrom;
|
|
tFrom.n = nFrom;
|
|
pRaise = sqlite3Expr(db, TK_RAISE, "foreign key constraint failed");
|
|
if (pRaise != null)
|
|
{
|
|
pRaise.affinity = (char)OE_Abort;
|
|
}
|
|
pSelect = sqlite3SelectNew(pParse,
|
|
sqlite3ExprListAppend(pParse, 0, pRaise),
|
|
sqlite3SrcListAppend(db, 0, tFrom, null),
|
|
pWhere,
|
|
null, null, null, 0, null, null
|
|
);
|
|
pWhere = null;
|
|
}
|
|
|
|
/* Disable lookaside memory allocation */
|
|
enableLookaside = db.lookaside.bEnabled;
|
|
db.lookaside.bEnabled = 0;
|
|
|
|
pTrigger = new Trigger();
|
|
//(Trigger*)sqlite3DbMallocZero( db,
|
|
// sizeof( Trigger ) + /* struct Trigger */
|
|
// sizeof( TriggerStep ) + /* Single step in trigger program */
|
|
// nFrom + 1 /* Space for pStep.target.z */
|
|
// );
|
|
//if ( pTrigger )
|
|
{
|
|
pStep = pTrigger.step_list = new TriggerStep();// = (TriggerStep)pTrigger[1];
|
|
//pStep.target.z = pStep[1];
|
|
pStep.target.n = nFrom;
|
|
pStep.target.z = zFrom;// memcpy( (char*)pStep.target.z, zFrom, nFrom );
|
|
|
|
pStep.pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
|
|
pStep.pExprList = sqlite3ExprListDup(db, pList, EXPRDUP_REDUCE);
|
|
pStep.pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
|
|
if (pWhen != null)
|
|
{
|
|
pWhen = sqlite3PExpr(pParse, TK_NOT, pWhen, 0, 0);
|
|
pTrigger.pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
|
|
}
|
|
}
|
|
|
|
/* Re-enable the lookaside buffer, if it was disabled earlier. */
|
|
db.lookaside.bEnabled = enableLookaside;
|
|
|
|
sqlite3ExprDelete(db, ref pWhere);
|
|
sqlite3ExprDelete(db, ref pWhen);
|
|
sqlite3ExprListDelete(db, ref pList);
|
|
sqlite3SelectDelete(db, ref pSelect);
|
|
//if ( db.mallocFailed == 1 )
|
|
//{
|
|
// fkTriggerDelete( db, pTrigger );
|
|
// return 0;
|
|
//}
|
|
|
|
switch (action)
|
|
{
|
|
case OE_Restrict:
|
|
pStep.op = TK_SELECT;
|
|
break;
|
|
|
|
case OE_Cascade:
|
|
if (null == pChanges)
|
|
{
|
|
pStep.op = TK_DELETE;
|
|
break;
|
|
}
|
|
goto default;
|
|
default:
|
|
pStep.op = TK_UPDATE;
|
|
break;
|
|
}
|
|
pStep.pTrig = pTrigger;
|
|
pTrigger.pSchema = pTab.pSchema;
|
|
pTrigger.pTabSchema = pTab.pSchema;
|
|
pFKey.apTrigger[iAction] = pTrigger;
|
|
pTrigger.op = (byte)(pChanges != null ? TK_UPDATE : TK_DELETE);
|
|
}
|
|
|
|
return pTrigger;
|
|
}
|
|
|
|
/*
|
|
** This function is called when deleting or updating a row to implement
|
|
** any required CASCADE, SET NULL or SET DEFAULT actions.
|
|
*/
|
|
|
|
private static void sqlite3FkActions(
|
|
Parse pParse, /* Parse context */
|
|
Table pTab, /* Table being updated or deleted from */
|
|
ExprList pChanges, /* Change-list for UPDATE, NULL for DELETE */
|
|
int regOld /* Address of array containing old row */
|
|
)
|
|
{
|
|
/* If foreign-key support is enabled, iterate through all FKs that
|
|
** refer to table pTab. If there is an action a6ssociated with the FK
|
|
** for this operation (either update or delete), invoke the associated
|
|
** trigger sub-program. */
|
|
if ((pParse.db.flags & SQLITE_ForeignKeys) != 0)
|
|
{
|
|
FKey pFKey; /* Iterator variable */
|
|
for (pFKey = sqlite3FkReferences(pTab); pFKey != null; pFKey = pFKey.pNextTo)
|
|
{
|
|
Trigger pAction = fkActionTrigger(pParse, pTab, pFKey, pChanges);
|
|
if (pAction != null)
|
|
{
|
|
sqlite3CodeRowTriggerDirect(pParse, pAction, pTab, regOld, OE_Abort, 0);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#endif //* ifndef SQLITE_OMIT_TRIGGER */
|
|
|
|
/*
|
|
** Free all memory associated with foreign key definitions attached to
|
|
** table pTab. Remove the deleted foreign keys from the Schema.fkeyHash
|
|
** hash table.
|
|
*/
|
|
|
|
private static void sqlite3FkDelete(sqlite3 db, Table pTab)
|
|
{
|
|
FKey pFKey; /* Iterator variable */
|
|
FKey pNext; /* Copy of pFKey.pNextFrom */
|
|
|
|
Debug.Assert(db == null || sqlite3SchemaMutexHeld(db, 0, pTab.pSchema));
|
|
for (pFKey = pTab.pFKey; pFKey != null; pFKey = pNext)
|
|
{
|
|
/* Remove the FK from the fkeyHash hash table. */
|
|
//if ( null == db || db.pnBytesFreed == 0 )
|
|
{
|
|
if (pFKey.pPrevTo != null)
|
|
{
|
|
pFKey.pPrevTo.pNextTo = pFKey.pNextTo;
|
|
}
|
|
else
|
|
{
|
|
FKey p = pFKey.pNextTo;
|
|
string z = (p != null ? pFKey.pNextTo.zTo : pFKey.zTo);
|
|
sqlite3HashInsert(ref pTab.pSchema.fkeyHash, z, sqlite3Strlen30(z), p);
|
|
}
|
|
if (pFKey.pNextTo != null)
|
|
{
|
|
pFKey.pNextTo.pPrevTo = pFKey.pPrevTo;
|
|
}
|
|
}
|
|
|
|
/* EV: R-30323-21917 Each foreign key constraint in SQLite is
|
|
** classified as either immediate or deferred.
|
|
*/
|
|
Debug.Assert(pFKey.isDeferred == 0 || pFKey.isDeferred == 1);
|
|
|
|
/* Delete any triggers created to implement actions for this FK. */
|
|
#if !SQLITE_OMIT_TRIGGER
|
|
fkTriggerDelete(db, pFKey.apTrigger[0]);
|
|
fkTriggerDelete(db, pFKey.apTrigger[1]);
|
|
#endif
|
|
|
|
pNext = pFKey.pNextFrom;
|
|
sqlite3DbFree(db, ref pFKey);
|
|
}
|
|
}
|
|
|
|
#endif //* ifndef SQLITE_OMIT_FOREIGN_KEY */
|
|
}
|
|
} |