aboutsummaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/build.c56
-rw-r--r--src/delete.c76
-rw-r--r--src/insert.c8
-rw-r--r--src/parse.y11
-rw-r--r--src/sqliteInt.h5
-rw-r--r--src/trigger.c140
-rw-r--r--src/update.c4
7 files changed, 168 insertions, 132 deletions
diff --git a/src/build.c b/src/build.c
index 5f89a717f..23f55a626 100644
--- a/src/build.c
+++ b/src/build.c
@@ -25,7 +25,7 @@
** ROLLBACK
** PRAGMA
**
-** $Id: build.c,v 1.91 2002/05/19 23:43:14 danielk1977 Exp $
+** $Id: build.c,v 1.92 2002/05/21 11:38:11 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -478,7 +478,7 @@ void sqliteStartTable(Parse *pParse, Token *pStart, Token *pName, int isTemp){
** now.
*/
if( !pParse->initFlag && (v = sqliteGetVdbe(pParse))!=0 ){
- sqliteBeginWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 0);
if( !isTemp ){
sqliteVdbeAddOp(v, OP_Integer, db->file_format, 0);
sqliteVdbeAddOp(v, OP_SetCookie, 0, 1);
@@ -1092,7 +1092,7 @@ void sqliteDropTable(Parse *pParse, Token *pName, int isView){
{ OP_Close, 0, 0, 0},
};
Index *pIdx;
- sqliteBeginWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 0);
/* Drop all triggers associated with the table being dropped */
while( pTable->pTrigger ){
Token tt;
@@ -1355,7 +1355,7 @@ void sqliteCreateIndex(
v = sqliteGetVdbe(pParse);
if( v==0 ) goto exit_create_index;
if( pTable!=0 ){
- sqliteBeginWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 0);
if( !isTemp ){
sqliteVdbeAddOp(v, OP_OpenWrite, 0, 2);
sqliteVdbeChangeP3(v, -1, MASTER_NAME, P3_STATIC);
@@ -1467,7 +1467,7 @@ void sqliteDropIndex(Parse *pParse, Token *pName){
int base;
Table *pTab = pIndex->pTable;
- sqliteBeginWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 0);
if( !pTab->isTemp ){
base = sqliteVdbeAddOpList(v, ArraySize(dropIndex), dropIndex);
sqliteVdbeChangeP3(v, base+2, pIndex->zName, P3_STATIC);
@@ -1588,7 +1588,7 @@ void sqliteCopy(
v = sqliteGetVdbe(pParse);
if( v ){
int openOp;
- sqliteBeginMultiWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 1);
addr = sqliteVdbeAddOp(v, OP_FileOpen, 0, 0);
sqliteVdbeChangeP3(v, addr, pFilename->z, pFilename->n);
sqliteVdbeDequoteP3(v, addr);
@@ -1669,7 +1669,7 @@ void sqliteBeginTransaction(Parse *pParse, int onError){
if( pParse==0 || (db=pParse->db)==0 || db->pBe==0 ) return;
if( pParse->nErr || sqlite_malloc_failed ) return;
if( db->flags & SQLITE_InTrans ) return;
- sqliteBeginWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 0);
db->flags |= SQLITE_InTrans;
db->onError = onError;
}
@@ -1708,32 +1708,18 @@ void sqliteRollbackTransaction(Parse *pParse){
/*
** Generate VDBE code that prepares for doing an operation that
-** might change the database. The operation will be atomic in the
-** sense that it will either do its changes completely or not at
-** all. So there is no need to set a checkpoint is a transaction
-** is already in effect.
-*/
-void sqliteBeginWriteOperation(Parse *pParse){
- Vdbe *v;
- v = sqliteGetVdbe(pParse);
- if( v==0 ) return;
- if( pParse->trigStack ) return; /* if this is in a trigger */
- if( (pParse->db->flags & SQLITE_InTrans)==0 ){
- sqliteVdbeAddOp(v, OP_Transaction, 0, 0);
- sqliteVdbeAddOp(v, OP_VerifyCookie, pParse->db->schema_cookie, 0);
- pParse->schemaVerified = 1;
- }
-}
-
-/*
-** Generate VDBE code that prepares for doing an operation that
-** might change the database. The operation might not be atomic in
-** the sense that an error may be discovered and the operation might
-** abort after some changes have been made. If we are in the middle
-** of a transaction, then this sets a checkpoint. If we are not in
-** a transaction, then start a transaction.
+** might change the database.
+**
+** This routine starts a new transaction if we are not already within
+** a transaction. If we are already within a transaction, then a checkpoint
+** is set if the setCheckpoint parameter is true. A checkpoint should
+** be set for operations that might fail (due to a constraint) part of
+** the way through and which will need to undo some writes without having to
+** rollback the whole transaction. For operations where all constraints
+** can be checked before any changes are made to the database, it is never
+** necessary to undo a write and the checkpoint should not be set.
*/
-void sqliteBeginMultiWriteOperation(Parse *pParse){
+void sqliteBeginWriteOperation(Parse *pParse, int setCheckpoint){
Vdbe *v;
v = sqliteGetVdbe(pParse);
if( v==0 ) return;
@@ -1742,7 +1728,7 @@ void sqliteBeginMultiWriteOperation(Parse *pParse){
sqliteVdbeAddOp(v, OP_Transaction, 0, 0);
sqliteVdbeAddOp(v, OP_VerifyCookie, pParse->db->schema_cookie, 0);
pParse->schemaVerified = 1;
- }else{
+ }else if( setCheckpoint ){
sqliteVdbeAddOp(v, OP_Checkpoint, 0, 0);
}
}
@@ -1844,7 +1830,7 @@ void sqlitePragma(Parse *pParse, Token *pLeft, Token *pRight, int minusFlag){
int addr;
int size = atoi(zRight);
if( size<0 ) size = -size;
- sqliteBeginWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 0);
sqliteVdbeAddOp(v, OP_Integer, size, 0);
sqliteVdbeAddOp(v, OP_ReadCookie, 0, 2);
addr = sqliteVdbeAddOp(v, OP_Integer, 0, 0);
@@ -1935,7 +1921,7 @@ void sqlitePragma(Parse *pParse, Token *pLeft, Token *pRight, int minusFlag){
int addr;
int size = db->cache_size;
if( size<0 ) size = -size;
- sqliteBeginWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 0);
sqliteVdbeAddOp(v, OP_ReadCookie, 0, 2);
sqliteVdbeAddOp(v, OP_Dup, 0, 0);
addr = sqliteVdbeAddOp(v, OP_Integer, 0, 0);
diff --git a/src/delete.c b/src/delete.c
index 417ed2fd6..bcbe5ea81 100644
--- a/src/delete.c
+++ b/src/delete.c
@@ -12,7 +12,7 @@
** This file contains C code routines that are called by the parser
** to handle DELETE FROM statements.
**
-** $Id: delete.c,v 1.33 2002/05/19 23:43:14 danielk1977 Exp $
+** $Id: delete.c,v 1.34 2002/05/21 11:38:11 drh Exp $
*/
#include "sqliteInt.h"
@@ -75,6 +75,7 @@ void sqliteDeleteFrom(
){
Vdbe *v; /* The virtual database engine */
Table *pTab; /* The table from which records will be deleted */
+ char *zTab; /* Name of the table from which we are deleting */
IdList *pTabList; /* An ID list holding pTab and nothing else */
int end, addr; /* A couple addresses of generated code */
int i; /* Loop counter */
@@ -96,32 +97,28 @@ void sqliteDeleteFrom(
/* Check for the special case of a VIEW with one or more ON DELETE triggers
** defined
*/
- {
- Table *pTab;
- char *zTab = sqliteTableNameFromToken(pTableName);
-
- if( zTab != 0 ){
- pTab = sqliteFindTable(pParse->db, zTab);
- if( pTab ){
- row_triggers_exist =
- sqliteTriggersExist(pParse, pTab->pTrigger,
- TK_DELETE, TK_BEFORE, TK_ROW, 0) ||
- sqliteTriggersExist(pParse, pTab->pTrigger,
- TK_DELETE, TK_AFTER, TK_ROW, 0);
- }
- sqliteFree(zTab);
- if( row_triggers_exist && pTab->pSelect ){
- /* Just fire VIEW triggers */
- sqliteViewTriggers(pParse, pTab, pWhere, OE_Replace, 0);
- return;
- }
+ zTab = sqliteTableNameFromToken(pTableName);
+ if( zTab != 0 ){
+ pTab = sqliteFindTable(pParse->db, zTab);
+ if( pTab ){
+ row_triggers_exist =
+ sqliteTriggersExist(pParse, pTab->pTrigger,
+ TK_DELETE, TK_BEFORE, TK_ROW, 0) ||
+ sqliteTriggersExist(pParse, pTab->pTrigger,
+ TK_DELETE, TK_AFTER, TK_ROW, 0);
+ }
+ sqliteFree(zTab);
+ if( row_triggers_exist && pTab->pSelect ){
+ /* Just fire VIEW triggers */
+ sqliteViewTriggers(pParse, pTab, pWhere, OE_Replace, 0);
+ return;
}
}
/* Locate the table which we want to delete. This table has to be
** put in an IdList structure because some of the subroutines we
** will be calling are designed to work with multiple tables and expect
- ** an IdList* parameter instead of just a Table* parameger.
+ ** an IdList* parameter instead of just a Table* parameter.
*/
pTabList = sqliteTableTokenToIdList(pParse, pTableName);
if( pTabList==0 ) goto delete_from_cleanup;
@@ -129,6 +126,8 @@ void sqliteDeleteFrom(
pTab = pTabList->a[0].pTab;
assert( pTab->pSelect==0 ); /* This table is not a view */
+ /* Allocate a cursor used to store the old.* data for a trigger.
+ */
if( row_triggers_exist ){
oldIdx = pParse->nTab++;
}
@@ -151,11 +150,7 @@ void sqliteDeleteFrom(
if( v==0 ){
goto delete_from_cleanup;
}
- if( row_triggers_exist ){
- sqliteBeginMultiWriteOperation(pParse);
- } else {
- sqliteBeginWriteOperation(pParse);
- }
+ sqliteBeginWriteOperation(pParse, row_triggers_exist);
/* Initialize the counter of the number of rows deleted, if
** we are counting rows.
@@ -165,7 +160,8 @@ void sqliteDeleteFrom(
}
/* Special case: A DELETE without a WHERE clause deletes everything.
- ** It is easier just to erase the whole table.
+ ** It is easier just to erase the whole table. Note, however, that
+ ** this means that the row change count will be incorrect.
*/
if( pWhere==0 && !row_triggers_exist ){
if( db->flags & SQLITE_CountRows ){
@@ -215,8 +211,10 @@ void sqliteDeleteFrom(
sqliteVdbeAddOp(v, OP_ListRewind, 0, 0);
end = sqliteVdbeMakeLabel(v);
+ /* This is the beginning of the delete loop when there are
+ ** row triggers.
+ */
if( row_triggers_exist ){
- int ii;
addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end);
sqliteVdbeAddOp(v, OP_Dup, 0, 0);
@@ -226,11 +224,11 @@ void sqliteDeleteFrom(
sqliteVdbeAddOp(v, OP_OpenTemp, oldIdx, 0);
sqliteVdbeAddOp(v, OP_Integer, 13, 0);
- for(ii = 0; ii<pTab->nCol; ii++){
- if( ii==pTab->iPKey ){
+ for(i = 0; i<pTab->nCol; i++){
+ if( i==pTab->iPKey ){
sqliteVdbeAddOp(v, OP_Recno, base, 0);
} else {
- sqliteVdbeAddOp(v, OP_Column, base, ii);
+ sqliteVdbeAddOp(v, OP_Column, base, i);
}
}
sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
@@ -242,6 +240,12 @@ void sqliteDeleteFrom(
oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
}
+ /* Open cursors for the table we are deleting from and all its
+ ** indices. If there are row triggers, this happens inside the
+ ** OP_ListRead loop because the cursor have to all be closed
+ ** before the trigger fires. If there are no row triggers, the
+ ** cursors are opened only once on the outside the loop.
+ */
pParse->nTab = base + 1;
openOp = pTab->isTemp ? OP_OpenWrAux : OP_OpenWrite;
sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
@@ -249,12 +253,18 @@ void sqliteDeleteFrom(
sqliteVdbeAddOp(v, openOp, pParse->nTab++, pIdx->tnum);
}
+ /* This is the beginning of the delete loop when there are no
+ ** row triggers */
if( !row_triggers_exist ){
addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end);
}
- sqliteGenerateRowDelete(v, pTab, base, pParse->trigStack?0:1);
+ /* Delete the row */
+ sqliteGenerateRowDelete(v, pTab, base, pParse->trigStack==0);
+ /* If there are row triggers, close all cursors then invoke
+ ** the AFTER triggers
+ */
if( row_triggers_exist ){
for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
sqliteVdbeAddOp(v, OP_Close, base + i, pIdx->tnum);
@@ -264,10 +274,12 @@ void sqliteDeleteFrom(
oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
}
+ /* End of the delete loop */
sqliteVdbeAddOp(v, OP_Goto, 0, addr);
sqliteVdbeResolveLabel(v, end);
sqliteVdbeAddOp(v, OP_ListReset, 0, 0);
+ /* Close the cursors after the loop if there are no row triggers */
if( !row_triggers_exist ){
for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
sqliteVdbeAddOp(v, OP_Close, base + i, pIdx->tnum);
diff --git a/src/insert.c b/src/insert.c
index fab85eddb..091ed75a9 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -12,7 +12,7 @@
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
-** $Id: insert.c,v 1.55 2002/05/19 23:43:14 danielk1977 Exp $
+** $Id: insert.c,v 1.56 2002/05/21 11:38:11 drh Exp $
*/
#include "sqliteInt.h"
@@ -95,11 +95,7 @@ void sqliteInsert(
*/
v = sqliteGetVdbe(pParse);
if( v==0 ) goto insert_cleanup;
- if( pSelect || row_triggers_exist ){
- sqliteBeginMultiWriteOperation(pParse);
- }else{
- sqliteBeginWriteOperation(pParse);
- }
+ sqliteBeginWriteOperation(pParse, pSelect || row_triggers_exist);
/* if there are row triggers, allocate a temp table for new.* references. */
if( row_triggers_exist ){
diff --git a/src/parse.y b/src/parse.y
index bc60a78b6..cffdce119 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -14,7 +14,7 @@
** the parser. Lemon will also generate a header file containing
** numeric codes for all of the tokens.
**
-** @(#) $Id: parse.y,v 1.65 2002/05/15 14:17:45 drh Exp $
+** @(#) $Id: parse.y,v 1.66 2002/05/21 11:38:12 drh Exp $
*/
%token_prefix TK_
%token_type {Token}
@@ -98,27 +98,32 @@ columnid ::= ids(X). {sqliteAddColumn(pParse,&X);}
// An IDENTIFIER can be a generic identifier, or one of several
// keywords. Any non-standard keyword can also be an identifier.
-// We also make DESC and identifier since it comes up so often (as
-// an abbreviation of "description").
//
%type id {Token}
id(A) ::= ABORT(X). {A = X;}
+id(A) ::= AFTER(X). {A = X;}
id(A) ::= ASC(X). {A = X;}
+id(A) ::= BEFORE(X). {A = X;}
id(A) ::= BEGIN(X). {A = X;}
id(A) ::= CLUSTER(X). {A = X;}
id(A) ::= CONFLICT(X). {A = X;}
id(A) ::= COPY(X). {A = X;}
id(A) ::= DELIMITERS(X). {A = X;}
id(A) ::= DESC(X). {A = X;}
+id(A) ::= EACH(X). {A = X;}
id(A) ::= END(X). {A = X;}
id(A) ::= EXPLAIN(X). {A = X;}
id(A) ::= FAIL(X). {A = X;}
+id(A) ::= FOR(X). {A = X;}
id(A) ::= ID(X). {A = X;}
id(A) ::= IGNORE(X). {A = X;}
+id(A) ::= INSTEAD(X). {A = X;}
id(A) ::= KEY(X). {A = X;}
+id(A) ::= OF(X). {A = X;}
id(A) ::= OFFSET(X). {A = X;}
id(A) ::= PRAGMA(X). {A = X;}
id(A) ::= REPLACE(X). {A = X;}
+id(A) ::= ROW(X). {A = X;}
id(A) ::= TEMP(X). {A = X;}
id(A) ::= TRIGGER(X). {A = X;}
id(A) ::= VACUUM(X). {A = X;}
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 9fd9b879e..92716c63f 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -11,7 +11,7 @@
*************************************************************************
** Internal interface definitions for SQLite.
**
-** @(#) $Id: sqliteInt.h,v 1.110 2002/05/16 00:13:12 danielk1977 Exp $
+** @(#) $Id: sqliteInt.h,v 1.111 2002/05/21 11:38:12 drh Exp $
*/
#include "sqlite.h"
#include "hash.h"
@@ -798,8 +798,7 @@ void sqliteGenerateRowDelete(Vdbe*, Table*, int, int);
void sqliteGenerateRowIndexDelete(Vdbe*, Table*, int, char*);
void sqliteGenerateConstraintChecks(Parse*,Table*,int,char*,int,int,int,int);
void sqliteCompleteInsertion(Parse*, Table*, int, char*, int, int);
-void sqliteBeginWriteOperation(Parse*);
-void sqliteBeginMultiWriteOperation(Parse*);
+void sqliteBeginWriteOperation(Parse*, int);
void sqliteEndWriteOperation(Parse*);
void sqliteExprMoveStrings(Expr*, int);
void sqliteExprListMoveStrings(ExprList*, int);
diff --git a/src/trigger.c b/src/trigger.c
index d0141b0eb..d26ddb9ea 100644
--- a/src/trigger.c
+++ b/src/trigger.c
@@ -95,32 +95,32 @@ void sqliteCreateTrigger(
** build the sqlite_master entry
*/
if( !pParse->initFlag && !tab->isTemp ){
+ static VdbeOp insertTrig[] = {
+ { OP_OpenWrite, 0, 2, MASTER_NAME},
+ { OP_NewRecno, 0, 0, 0 },
+ { OP_String, 0, 0, "trigger" },
+ { OP_String, 0, 0, 0 }, /* 3: trigger name */
+ { OP_String, 0, 0, 0 }, /* 4: table name */
+ { OP_Integer, 0, 0, 0 },
+ { OP_String, 0, 0, 0 }, /* 6: SQL */
+ { OP_MakeRecord, 5, 0, 0 },
+ { OP_PutIntKey, 0, 0, 0 },
+ { OP_Integer, 0, 0, 0 }, /* 9: Next cookie */
+ { OP_SetCookie, 0, 0, 0 },
+ { OP_Close, 0, 0, 0 },
+ };
+ int addr;
+ Vdbe *v;
/* Make an entry in the sqlite_master table */
- sqliteBeginWriteOperation(pParse);
-
- sqliteVdbeAddOp(pParse->pVdbe, OP_OpenWrite, 0, 2);
- sqliteVdbeChangeP3(pParse->pVdbe, -1, MASTER_NAME, P3_STATIC);
- sqliteVdbeAddOp(pParse->pVdbe, OP_NewRecno, 0, 0);
- sqliteVdbeAddOp(pParse->pVdbe, OP_String, 0, 0);
- sqliteVdbeChangeP3(pParse->pVdbe, -1, "trigger", P3_STATIC);
- sqliteVdbeAddOp(pParse->pVdbe, OP_String, 0, 0);
- sqliteVdbeChangeP3(pParse->pVdbe, -1, nt->name, 0);
- sqliteVdbeAddOp(pParse->pVdbe, OP_String, 0, 0);
- sqliteVdbeChangeP3(pParse->pVdbe, -1, nt->table, 0);
- sqliteVdbeAddOp(pParse->pVdbe, OP_Integer, 0, 0);
- sqliteVdbeAddOp(pParse->pVdbe, OP_String, 0, 0);
- sqliteVdbeChangeP3(pParse->pVdbe, -1, nt->strings, 0);
- sqliteVdbeAddOp(pParse->pVdbe, OP_MakeRecord, 5, 0);
- sqliteVdbeAddOp(pParse->pVdbe, OP_PutIntKey, 0, 1);
-
- /* Change the cookie, since the schema is changed */
+ v = sqliteGetVdbe(pParse);
+ sqliteBeginWriteOperation(pParse, 0);
+ addr = sqliteVdbeAddOpList(v, ArraySize(insertTrig), insertTrig);
+ sqliteVdbeChangeP3(v, addr+3, nt->name, 0);
+ sqliteVdbeChangeP3(v, addr+4, nt->table, 0);
+ sqliteVdbeChangeP3(v, addr+6, nt->strings, 0);
sqliteChangeCookie(pParse->db);
- sqliteVdbeAddOp(pParse->pVdbe, OP_Integer, pParse->db->next_cookie, 0);
- sqliteVdbeAddOp(pParse->pVdbe, OP_SetCookie, 0, 0);
-
- sqliteVdbeAddOp(pParse->pVdbe, OP_Close, 0, 0);
-
+ sqliteVdbeChangeP1(v, addr+9, pParse->db->next_cookie);
sqliteEndWriteOperation(pParse);
}
@@ -160,8 +160,14 @@ trigger_cleanup:
}
}
-TriggerStep *sqliteTriggerSelectStep(Select * pSelect)
-{
+/*
+** Turn a SELECT statement (that the pSelect parameter points to) into
+** a trigger step. Return a pointer to a TriggerStep structure.
+**
+** The parser calls this routine when it finds a SELECT statement in
+** body of a TRIGGER.
+*/
+TriggerStep *sqliteTriggerSelectStep(Select *pSelect){
TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep));
pTriggerStep->op = TK_SELECT;
@@ -171,12 +177,19 @@ TriggerStep *sqliteTriggerSelectStep(Select * pSelect)
return pTriggerStep;
}
+/*
+** Build a trigger step out of an INSERT statement. Return a pointer
+** to the new trigger step.
+**
+** The parser calls this routine when it sees an INSERT inside the
+** body of a trigger.
+*/
TriggerStep *sqliteTriggerInsertStep(
- Token *pTableName,
- IdList *pColumn,
- ExprList *pEList,
- Select *pSelect,
- int orconf
+ Token *pTableName, /* Name of the table into which we insert */
+ IdList *pColumn, /* List of columns in pTableName to insert into */
+ ExprList *pEList, /* The VALUE clause: a list of values to be inserted */
+ Select *pSelect, /* A SELECT statement that supplies values */
+ int orconf /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */
){
TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep));
@@ -193,12 +206,17 @@ TriggerStep *sqliteTriggerInsertStep(
return pTriggerStep;
}
+/*
+** Construct a trigger step that implements an UPDATE statement and return
+** a pointer to that trigger step. The parser calls this routine when it
+** sees an UPDATE statement inside the body of a CREATE TRIGGER.
+*/
TriggerStep *sqliteTriggerUpdateStep(
- Token *pTableName,
- ExprList *pEList,
- Expr *pWhere,
- int orconf)
-{
+ Token *pTableName, /* Name of the table to be updated */
+ ExprList *pEList, /* The SET clause: list of column and new values */
+ Expr *pWhere, /* The WHERE clause */
+ int orconf /* The conflict algorithm. (OE_Abort, OE_Ignore, etc) */
+){
TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep));
pTriggerStep->op = TK_UPDATE;
@@ -210,8 +228,12 @@ TriggerStep *sqliteTriggerUpdateStep(
return pTriggerStep;
}
-TriggerStep *sqliteTriggerDeleteStep(Token *pTableName, Expr *pWhere)
-{
+/*
+** Construct a trigger step that implements a DELETE statement and return
+** a pointer to that trigger step. The parser calls this routine when it
+** sees a DELETE statement inside the body of a CREATE TRIGGER.
+*/
+TriggerStep *sqliteTriggerDeleteStep(Token *pTableName, Expr *pWhere){
TriggerStep * pTriggerStep = sqliteMalloc(sizeof(TriggerStep));
pTriggerStep->op = TK_DELETE;
@@ -328,7 +350,7 @@ void sqliteDropTrigger(Parse *pParse, Token *pName, int nested)
};
if( !nested ){
- sqliteBeginWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 0);
}
base = sqliteVdbeAddOpList(pParse->pVdbe,
ArraySize(dropTrigger), dropTrigger);
@@ -345,8 +367,16 @@ void sqliteDropTrigger(Parse *pParse, Token *pName, int nested)
sqliteFree(zName);
}
-static int checkColumnOverLap(IdList * pIdList, ExprList * pEList)
-{
+/*
+** pEList is the SET clause of an UPDATE statement. Each entry
+** in pEList is of the format <id>=<expr>. If any of the entries
+** in pEList have an <id> which matches an identifier in pIdList,
+** then return TRUE. If pIdList==NULL, then it is considered a
+** wildcard that matches anything. Likewise if pEList==NULL then
+** it matches anything so always return true. Return false only
+** if there is no match.
+*/
+static int checkColumnOverLap(IdList *pIdList, ExprList *pEList){
int i, e;
if( !pIdList )return 1;
if( !pEList )return 1;
@@ -378,13 +408,13 @@ int always_code_trigger_setup = 0;
* found in the list specified as pTrigger.
*/
int sqliteTriggersExist(
- Parse *pParse,
- Trigger *pTrigger,
+ Parse *pParse, /* Used to check for recursive triggers */
+ Trigger *pTrigger, /* A list of triggers associated with a table */
int op, /* one of TK_DELETE, TK_INSERT, TK_UPDATE */
int tr_tm, /* one of TK_BEFORE, TK_AFTER */
int foreach, /* one of TK_ROW or TK_STATEMENT */
- ExprList *pChanges)
-{
+ ExprList *pChanges /* Columns that change in an UPDATE statement */
+){
Trigger * pTriggerCursor;
if( always_code_trigger_setup ){
@@ -410,10 +440,14 @@ int sqliteTriggersExist(
return 0;
}
+/*
+** Generate VDBE code for zero or more statements inside the body of a
+** trigger.
+*/
static int codeTriggerProgram(
- Parse *pParse,
- TriggerStep *pStepList,
- int orconfin
+ Parse *pParse, /* The parser context */
+ TriggerStep *pStepList, /* List of statements inside the trigger body */
+ int orconfin /* Conflict algorithm. (OE_Abort, etc) */
){
TriggerStep * pTriggerStep = pStepList;
int orconf;
@@ -470,11 +504,15 @@ static int codeTriggerProgram(
**
** When the code that this function generates is executed, the following
** must be true:
-** 1. NO vdbe cursors must be open.
+**
+** 1. No cursors may be open in the main database. (But newIdx and oldIdx
+** can be indices of cursors in temporary tables. See below.)
+**
** 2. If the triggers being coded are ON INSERT or ON UPDATE triggers, then
** a temporary vdbe cursor (index newIdx) must be open and pointing at
** a row containing values to be substituted for new.* expressions in the
** trigger program(s).
+**
** 3. If the triggers being coded are ON DELETE or ON UPDATE triggers, then
** a temporary vdbe cursor (index oldIdx) must be open and pointing at
** a row containing values to be substituted for old.* expressions in the
@@ -489,8 +527,8 @@ int sqliteCodeRowTrigger(
Table *pTab, /* The table to code triggers from */
int newIdx, /* The indice of the "new" row to access */
int oldIdx, /* The indice of the "old" row to access */
- int orconf) /* ON CONFLICT policy */
-{
+ int orconf /* ON CONFLICT policy */
+){
Trigger * pTrigger;
TriggerStack * pTriggerStack;
@@ -611,7 +649,7 @@ void sqliteViewTriggers(
v = sqliteGetVdbe(pParse);
assert(v);
- sqliteBeginMultiWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 1);
/* Allocate temp tables */
oldIdx = pParse->nTab++;
diff --git a/src/update.c b/src/update.c
index 48ea1b98a..95923ec18 100644
--- a/src/update.c
+++ b/src/update.c
@@ -12,7 +12,7 @@
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
-** $Id: update.c,v 1.39 2002/05/19 23:43:14 danielk1977 Exp $
+** $Id: update.c,v 1.40 2002/05/21 11:38:12 drh Exp $
*/
#include "sqliteInt.h"
@@ -177,7 +177,7 @@ void sqliteUpdate(
*/
v = sqliteGetVdbe(pParse);
if( v==0 ) goto update_cleanup;
- sqliteBeginMultiWriteOperation(pParse);
+ sqliteBeginWriteOperation(pParse, 1);
/* Begin the database scan
*/
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-17 09:48:39 +0000