Google Git
Sign in
cobalt / cobalt / 25902c6cb1ab9cfd8ae2ee6b0fb52953f73deda5 / . / third_party / perfetto / buildtools / sqlite_src / src / update.c
blob: 3fd78a0b5af545861b3cabc49a7361559ea8382f [file] [log] [blame]
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
*/
#include "sqliteInt.h"
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
Parse *pParse, /* The parsing context */
SrcList *pSrc, /* The virtual table to be modified */
Table *pTab, /* The virtual table */
ExprList *pChanges, /* The columns to change in the UPDATE statement */
Expr *pRowidExpr, /* Expression used to recompute the rowid */
int *aXRef, /* Mapping from columns of pTab to entries in pChanges */
Expr *pWhere, /* WHERE clause of the UPDATE statement */
int onError /* ON CONFLICT strategy */
);
#endif /* SQLITE_OMIT_VIRTUALTABLE */
/*
** The most recently coded instruction was an OP_Column to retrieve the
** i-th column of table pTab. This routine sets the P4 parameter of the
** OP_Column to the default value, if any.
**
** The default value of a column is specified by a DEFAULT clause in the
** column definition. This was either supplied by the user when the table
** was created, or added later to the table definition by an ALTER TABLE
** command. If the latter, then the row-records in the table btree on disk
** may not contain a value for the column and the default value, taken
** from the P4 parameter of the OP_Column instruction, is returned instead.
** If the former, then all row-records are guaranteed to include a value
** for the column and the P4 value is not required.
**
** Column definitions created by an ALTER TABLE command may only have
** literal default values specified: a number, null or a string. (If a more
** complicated default expression value was provided, it is evaluated
** when the ALTER TABLE is executed and one of the literal values written
** into the sqlite_schema table.)
**
** Therefore, the P4 parameter is only required if the default value for
** the column is a literal number, string or null. The sqlite3ValueFromExpr()
** function is capable of transforming these types of expressions into
** sqlite3_value objects.
**
** If column as REAL affinity and the table is an ordinary b-tree table
** (not a virtual table) then the value might have been stored as an
** integer. In that case, add an OP_RealAffinity opcode to make sure
** it has been converted into REAL.
*/
void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){
assert( pTab!=0 );
if( !IsView(pTab) ){
sqlite3_value *pValue = 0;
u8 enc = ENC(sqlite3VdbeDb(v));
Column *pCol = &pTab->aCol[i];
VdbeComment((v, "%s.%s", pTab->zName, pCol->zCnName));
assert( i<pTab->nCol );
sqlite3ValueFromExpr(sqlite3VdbeDb(v),
sqlite3ColumnExpr(pTab,pCol), enc,
pCol->affinity, &pValue);
if( pValue ){
sqlite3VdbeAppendP4(v, pValue, P4_MEM);
}
}
#ifndef SQLITE_OMIT_FLOATING_POINT
if( pTab->aCol[i].affinity==SQLITE_AFF_REAL && !IsVirtual(pTab) ){
sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
}
#endif
}
/*
** Check to see if column iCol of index pIdx references any of the
** columns defined by aXRef and chngRowid. Return true if it does
** and false if not. This is an optimization. False-positives are a
** performance degradation, but false-negatives can result in a corrupt
** index and incorrect answers.
**
** aXRef[j] will be non-negative if column j of the original table is
** being updated. chngRowid will be true if the rowid of the table is
** being updated.
*/
static int indexColumnIsBeingUpdated(
Index *pIdx, /* The index to check */
int iCol, /* Which column of the index to check */
int *aXRef, /* aXRef[j]>=0 if column j is being updated */
int chngRowid /* true if the rowid is being updated */
){
i16 iIdxCol = pIdx->aiColumn[iCol];
assert( iIdxCol!=XN_ROWID ); /* Cannot index rowid */
if( iIdxCol>=0 ){
return aXRef[iIdxCol]>=0;
}
assert( iIdxCol==XN_EXPR );
assert( pIdx->aColExpr!=0 );
assert( pIdx->aColExpr->a[iCol].pExpr!=0 );
return sqlite3ExprReferencesUpdatedColumn(pIdx->aColExpr->a[iCol].pExpr,
aXRef,chngRowid);
}
/*
** Check to see if index pIdx is a partial index whose conditional
** expression might change values due to an UPDATE. Return true if
** the index is subject to change and false if the index is guaranteed
** to be unchanged. This is an optimization. False-positives are a
** performance degradation, but false-negatives can result in a corrupt
** index and incorrect answers.
**
** aXRef[j] will be non-negative if column j of the original table is
** being updated. chngRowid will be true if the rowid of the table is
** being updated.
*/
static int indexWhereClauseMightChange(
Index *pIdx, /* The index to check */
int *aXRef, /* aXRef[j]>=0 if column j is being updated */
int chngRowid /* true if the rowid is being updated */
){
if( pIdx->pPartIdxWhere==0 ) return 0;
return sqlite3ExprReferencesUpdatedColumn(pIdx->pPartIdxWhere,
aXRef, chngRowid);
}
/*
** Allocate and return a pointer to an expression of type TK_ROW with
** Expr.iColumn set to value (iCol+1). The resolver will modify the
** expression to be a TK_COLUMN reading column iCol of the first
** table in the source-list (pSrc->a[0]).
*/
static Expr *exprRowColumn(Parse *pParse, int iCol){
Expr *pRet = sqlite3PExpr(pParse, TK_ROW, 0, 0);
if( pRet ) pRet->iColumn = iCol+1;
return pRet;
}
/*
** Assuming both the pLimit and pOrderBy parameters are NULL, this function
** generates VM code to run the query:
**
** SELECT <other-columns>, pChanges FROM pTabList WHERE pWhere
**
** and write the results to the ephemeral table already opened as cursor
** iEph. None of pChanges, pTabList or pWhere are modified or consumed by
** this function, they must be deleted by the caller.
**
** Or, if pLimit and pOrderBy are not NULL, and pTab is not a view:
**
** SELECT <other-columns>, pChanges FROM pTabList
** WHERE pWhere
** GROUP BY <other-columns>
** ORDER BY pOrderBy LIMIT pLimit
**
** If pTab is a view, the GROUP BY clause is omitted.
**
** Exactly how results are written to table iEph, and exactly what
** the <other-columns> in the query above are is determined by the type
** of table pTabList->a[0].pTab.
**
** If the table is a WITHOUT ROWID table, then argument pPk must be its
** PRIMARY KEY. In this case <other-columns> are the primary key columns
** of the table, in order. The results of the query are written to ephemeral
** table iEph as index keys, using OP_IdxInsert.
**
** If the table is actually a view, then <other-columns> are all columns of
** the view. The results are written to the ephemeral table iEph as records
** with automatically assigned integer keys.
**
** If the table is a virtual or ordinary intkey table, then <other-columns>
** is its rowid. For a virtual table, the results are written to iEph as
** records with automatically assigned integer keys For intkey tables, the
** rowid value in <other-columns> is used as the integer key, and the
** remaining fields make up the table record.
*/
static void updateFromSelect(
Parse *pParse, /* Parse context */
int iEph, /* Cursor for open eph. table */
Index *pPk, /* PK if table 0 is WITHOUT ROWID */
ExprList *pChanges, /* List of expressions to return */
SrcList *pTabList, /* List of tables to select from */
Expr *pWhere, /* WHERE clause for query */
ExprList *pOrderBy, /* ORDER BY clause */
Expr *pLimit /* LIMIT clause */
){
int i;
SelectDest dest;
Select *pSelect = 0;
ExprList *pList = 0;
ExprList *pGrp = 0;
Expr *pLimit2 = 0;
ExprList *pOrderBy2 = 0;
sqlite3 *db = pParse->db;
Table *pTab = pTabList->a[0].pTab;
SrcList *pSrc;
Expr *pWhere2;
int eDest;
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
if( pOrderBy && pLimit==0 ) {
sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on UPDATE");
return;
}
pOrderBy2 = sqlite3ExprListDup(db, pOrderBy, 0);
pLimit2 = sqlite3ExprDup(db, pLimit, 0);
#else
UNUSED_PARAMETER(pOrderBy);
UNUSED_PARAMETER(pLimit);
#endif
pSrc = sqlite3SrcListDup(db, pTabList, 0);
pWhere2 = sqlite3ExprDup(db, pWhere, 0);
assert( pTabList->nSrc>1 );
if( pSrc ){
pSrc->a[0].fg.notCte = 1;
pSrc->a[0].iCursor = -1;
pSrc->a[0].pTab->nTabRef--;
pSrc->a[0].pTab = 0;
}
if( pPk ){
for(i=0; i<pPk->nKeyCol; i++){
Expr *pNew = exprRowColumn(pParse, pPk->aiColumn[i]);
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
if( pLimit ){
pGrp = sqlite3ExprListAppend(pParse, pGrp, sqlite3ExprDup(db, pNew, 0));
}
#endif
pList = sqlite3ExprListAppend(pParse, pList, pNew);
}
eDest = IsVirtual(pTab) ? SRT_Table : SRT_Upfrom;
}else if( IsView(pTab) ){
for(i=0; i<pTab->nCol; i++){
pList = sqlite3ExprListAppend(pParse, pList, exprRowColumn(pParse, i));
}
eDest = SRT_Table;
}else{
eDest = IsVirtual(pTab) ? SRT_Table : SRT_Upfrom;
pList = sqlite3ExprListAppend(pParse, 0, sqlite3PExpr(pParse,TK_ROW,0,0));
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
if( pLimit ){
pGrp = sqlite3ExprListAppend(pParse, 0, sqlite3PExpr(pParse,TK_ROW,0,0));
}
#endif
}
assert( pChanges!=0 || pParse->db->mallocFailed );
if( pChanges ){
for(i=0; i<pChanges->nExpr; i++){
pList = sqlite3ExprListAppend(pParse, pList,
sqlite3ExprDup(db, pChanges->a[i].pExpr, 0)
);
}
}
pSelect = sqlite3SelectNew(pParse, pList,
pSrc, pWhere2, pGrp, 0, pOrderBy2, SF_UFSrcCheck|SF_IncludeHidden, pLimit2
);
if( pSelect ) pSelect->selFlags |= SF_OrderByReqd;
sqlite3SelectDestInit(&dest, eDest, iEph);
dest.iSDParm2 = (pPk ? pPk->nKeyCol : -1);
sqlite3Select(pParse, pSelect, &dest);
sqlite3SelectDelete(db, pSelect);
}
/*
** Process an UPDATE statement.
**
** UPDATE OR IGNORE tbl SET a=b, c=d FROM tbl2... WHERE e<5 AND f NOT NULL;
** \_______/ \_/ \______/ \_____/ \________________/
** onError | pChanges | pWhere
** \_______________________/
** pTabList
*/
void sqlite3Update(
Parse *pParse, /* The parser context */
SrcList *pTabList, /* The table in which we should change things */
ExprList *pChanges, /* Things to be changed */
Expr *pWhere, /* The WHERE clause. May be null */
int onError, /* How to handle constraint errors */
ExprList *pOrderBy, /* ORDER BY clause. May be null */
Expr *pLimit, /* LIMIT clause. May be null */
Upsert *pUpsert /* ON CONFLICT clause, or null */
){
int i, j, k; /* Loop counters */
Table *pTab; /* The table to be updated */
int addrTop = 0; /* VDBE instruction address of the start of the loop */
WhereInfo *pWInfo = 0; /* Information about the WHERE clause */
Vdbe *v; /* The virtual database engine */
Index *pIdx; /* For looping over indices */
Index *pPk; /* The PRIMARY KEY index for WITHOUT ROWID tables */
int nIdx; /* Number of indices that need updating */
int nAllIdx; /* Total number of indexes */
int iBaseCur; /* Base cursor number */
int iDataCur; /* Cursor for the canonical data btree */
int iIdxCur; /* Cursor for the first index */
sqlite3 *db; /* The database structure */
int *aRegIdx = 0; /* Registers for to each index and the main table */
int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the
** an expression for the i-th column of the table.
** aXRef[i]==-1 if the i-th column is not changed. */
u8 *aToOpen; /* 1 for tables and indices to be opened */
u8 chngPk; /* PRIMARY KEY changed in a WITHOUT ROWID table */
u8 chngRowid; /* Rowid changed in a normal table */
u8 chngKey; /* Either chngPk or chngRowid */
Expr *pRowidExpr = 0; /* Expression defining the new record number */
int iRowidExpr = -1; /* Index of "rowid=" (or IPK) assignment in pChanges */
AuthContext sContext; /* The authorization context */
NameContext sNC; /* The name-context to resolve expressions in */
int iDb; /* Database containing the table being updated */
int eOnePass; /* ONEPASS_XXX value from where.c */
int hasFK; /* True if foreign key processing is required */
int labelBreak; /* Jump here to break out of UPDATE loop */
int labelContinue; /* Jump here to continue next step of UPDATE loop */
int flags; /* Flags for sqlite3WhereBegin() */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True when updating a view (INSTEAD OF trigger) */
Trigger *pTrigger; /* List of triggers on pTab, if required */
int tmask; /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
#endif
int newmask; /* Mask of NEW.* columns accessed by BEFORE triggers */
int iEph = 0; /* Ephemeral table holding all primary key values */
int nKey = 0; /* Number of elements in regKey for WITHOUT ROWID */
int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */
int addrOpen = 0; /* Address of OP_OpenEphemeral */
int iPk = 0; /* First of nPk cells holding PRIMARY KEY value */
i16 nPk = 0; /* Number of components of the PRIMARY KEY */
int bReplace = 0; /* True if REPLACE conflict resolution might happen */
int bFinishSeek = 1; /* The OP_FinishSeek opcode is needed */
int nChangeFrom = 0; /* If there is a FROM, pChanges->nExpr, else 0 */
/* Register Allocations */
int regRowCount = 0; /* A count of rows changed */
int regOldRowid = 0; /* The old rowid */
int regNewRowid = 0; /* The new rowid */
int regNew = 0; /* Content of the NEW.* table in triggers */
int regOld = 0; /* Content of OLD.* table in triggers */
int regRowSet = 0; /* Rowset of rows to be updated */
int regKey = 0; /* composite PRIMARY KEY value */
memset(&sContext, 0, sizeof(sContext));
db = pParse->db;
assert( db->pParse==pParse );
if( pParse->nErr ){
goto update_cleanup;
}
assert( db->mallocFailed==0 );
/* Locate the table which we want to update.
*/
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ) goto update_cleanup;
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
/* Figure out if we have any triggers and if the table being
** updated is a view.
*/
#ifndef SQLITE_OMIT_TRIGGER
pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask);
isView = IsView(pTab);
assert( pTrigger || tmask==0 );
#else
# define pTrigger 0
# define isView 0
# define tmask 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
#if TREETRACE_ENABLED
if( sqlite3TreeTrace & 0x10000 ){
sqlite3TreeViewLine(0, "In sqlite3Update() at %s:%d", __FILE__, __LINE__);
sqlite3TreeViewUpdate(pParse->pWith, pTabList, pChanges, pWhere,
onError, pOrderBy, pLimit, pUpsert, pTrigger);
}
#endif
/* If there was a FROM clause, set nChangeFrom to the number of expressions
** in the change-list. Otherwise, set it to 0. There cannot be a FROM
** clause if this function is being called to generate code for part of
** an UPSERT statement. */
nChangeFrom = (pTabList->nSrc>1) ? pChanges->nExpr : 0;
assert( nChangeFrom==0 || pUpsert==0 );
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
if( !isView && nChangeFrom==0 ){
pWhere = sqlite3LimitWhere(
pParse, pTabList, pWhere, pOrderBy, pLimit, "UPDATE"
);
pOrderBy = 0;
pLimit = 0;
}
#endif
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto update_cleanup;
}
if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
goto update_cleanup;
}
/* Allocate a cursors for the main database table and for all indices.
** The index cursors might not be used, but if they are used they
** need to occur right after the database cursor. So go ahead and
** allocate enough space, just in case.
*/
iBaseCur = iDataCur = pParse->nTab++;
iIdxCur = iDataCur+1;
pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
testcase( pPk!=0 && pPk!=pTab->pIndex );
for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
if( pPk==pIdx ){
iDataCur = pParse->nTab;
}
pParse->nTab++;
}
if( pUpsert ){
/* On an UPSERT, reuse the same cursors already opened by INSERT */
iDataCur = pUpsert->iDataCur;
iIdxCur = pUpsert->iIdxCur;
pParse->nTab = iBaseCur;
}
pTabList->a[0].iCursor = iDataCur;
/* Allocate space for aXRef[], aRegIdx[], and aToOpen[].
** Initialize aXRef[] and aToOpen[] to their default values.
*/
aXRef = sqlite3DbMallocRawNN(db, sizeof(int) * (pTab->nCol+nIdx+1) + nIdx+2 );
if( aXRef==0 ) goto update_cleanup;
aRegIdx = aXRef+pTab->nCol;
aToOpen = (u8*)(aRegIdx+nIdx+1);
memset(aToOpen, 1, nIdx+1);
aToOpen[nIdx+1] = 0;
for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
/* Initialize the name-context */
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
sNC.uNC.pUpsert = pUpsert;
sNC.ncFlags = NC_UUpsert;
/* Begin generating code. */
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto update_cleanup;
/* Resolve the column names in all the expressions of the
** of the UPDATE statement. Also find the column index
** for each column to be updated in the pChanges array. For each
** column to be updated, make sure we have authorization to change
** that column.
*/
chngRowid = chngPk = 0;
for(i=0; i<pChanges->nExpr; i++){
u8 hCol = sqlite3StrIHash(pChanges->a[i].zEName);
/* If this is an UPDATE with a FROM clause, do not resolve expressions
** here. The call to sqlite3Select() below will do that. */
if( nChangeFrom==0 && sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){
goto update_cleanup;
}
for(j=0; j<pTab->nCol; j++){
if( pTab->aCol[j].hName==hCol
&& sqlite3StrICmp(pTab->aCol[j].zCnName, pChanges->a[i].zEName)==0
){
if( j==pTab->iPKey ){
chngRowid = 1;
pRowidExpr = pChanges->a[i].pExpr;
iRowidExpr = i;
}else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){
chngPk = 1;
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
else if( pTab->aCol[j].colFlags & COLFLAG_GENERATED ){
testcase( pTab->aCol[j].colFlags & COLFLAG_VIRTUAL );
testcase( pTab->aCol[j].colFlags & COLFLAG_STORED );
sqlite3ErrorMsg(pParse,
"cannot UPDATE generated column \"%s\"",
pTab->aCol[j].zCnName);
goto update_cleanup;
}
#endif
aXRef[j] = i;
break;
}
}
if( j>=pTab->nCol ){
if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zEName) ){
j = -1;
chngRowid = 1;
pRowidExpr = pChanges->a[i].pExpr;
iRowidExpr = i;
}else{
sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zEName);
pParse->checkSchema = 1;
goto update_cleanup;
}
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int rc;
rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
j<0 ? "ROWID" : pTab->aCol[j].zCnName,
db->aDb[iDb].zDbSName);
if( rc==SQLITE_DENY ){
goto update_cleanup;
}else if( rc==SQLITE_IGNORE ){
aXRef[j] = -1;
}
}
#endif
}
assert( (chngRowid & chngPk)==0 );
assert( chngRowid==0 || chngRowid==1 );
assert( chngPk==0 || chngPk==1 );
chngKey = chngRowid + chngPk;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/* Mark generated columns as changing if their generator expressions
** reference any changing column. The actual aXRef[] value for
** generated expressions is not used, other than to check to see that it
** is non-negative, so the value of aXRef[] for generated columns can be
** set to any non-negative number. We use 99999 so that the value is
** obvious when looking at aXRef[] in a symbolic debugger.
*/
if( pTab->tabFlags & TF_HasGenerated ){
int bProgress;
testcase( pTab->tabFlags & TF_HasVirtual );
testcase( pTab->tabFlags & TF_HasStored );
do{
bProgress = 0;
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]>=0 ) continue;
if( (pTab->aCol[i].colFlags & COLFLAG_GENERATED)==0 ) continue;
if( sqlite3ExprReferencesUpdatedColumn(
sqlite3ColumnExpr(pTab, &pTab->aCol[i]),
aXRef, chngRowid)
){
aXRef[i] = 99999;
bProgress = 1;
}
}
}while( bProgress );
}
#endif
/* The SET expressions are not actually used inside the WHERE loop.
** So reset the colUsed mask. Unless this is a virtual table. In that
** case, set all bits of the colUsed mask (to ensure that the virtual
** table implementation makes all columns available).
*/
pTabList->a[0].colUsed = IsVirtual(pTab) ? ALLBITS : 0;
hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);
/* There is one entry in the aRegIdx[] array for each index on the table
** being updated. Fill in aRegIdx[] with a register number that will hold
** the key for accessing each index.
*/
if( onError==OE_Replace ) bReplace = 1;
for(nAllIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nAllIdx++){
int reg;
if( chngKey || hasFK>1 || pIdx==pPk
|| indexWhereClauseMightChange(pIdx,aXRef,chngRowid)
){
reg = ++pParse->nMem;
pParse->nMem += pIdx->nColumn;
}else{
reg = 0;
for(i=0; i<pIdx->nKeyCol; i++){
if( indexColumnIsBeingUpdated(pIdx, i, aXRef, chngRowid) ){
reg = ++pParse->nMem;
pParse->nMem += pIdx->nColumn;
if( onError==OE_Default && pIdx->onError==OE_Replace ){
bReplace = 1;
}
break;
}
}
}
if( reg==0 ) aToOpen[nAllIdx+1] = 0;
aRegIdx[nAllIdx] = reg;
}
aRegIdx[nAllIdx] = ++pParse->nMem; /* Register storing the table record */
if( bReplace ){
/* If REPLACE conflict resolution might be invoked, open cursors on all
** indexes in case they are needed to delete records. */
memset(aToOpen, 1, nIdx+1);
}
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, pTrigger || hasFK, iDb);
/* Allocate required registers. */
if( !IsVirtual(pTab) ){
/* For now, regRowSet and aRegIdx[nAllIdx] share the same register.
** If regRowSet turns out to be needed, then aRegIdx[nAllIdx] will be
** reallocated. aRegIdx[nAllIdx] is the register in which the main
** table record is written. regRowSet holds the RowSet for the
** two-pass update algorithm. */
assert( aRegIdx[nAllIdx]==pParse->nMem );
regRowSet = aRegIdx[nAllIdx];
regOldRowid = regNewRowid = ++pParse->nMem;
if( chngPk || pTrigger || hasFK ){
regOld = pParse->nMem + 1;
pParse->nMem += pTab->nCol;
}
if( chngKey || pTrigger || hasFK ){
regNewRowid = ++pParse->nMem;
}
regNew = pParse->nMem + 1;
pParse->nMem += pTab->nCol;
}
/* Start the view context. */
if( isView ){
sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
}
/* If we are trying to update a view, realize that view into
** an ephemeral table.
*/
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
if( nChangeFrom==0 && isView ){
sqlite3MaterializeView(pParse, pTab,
pWhere, pOrderBy, pLimit, iDataCur
);
pOrderBy = 0;
pLimit = 0;
}
#endif
/* Resolve the column names in all the expressions in the
** WHERE clause.
*/
if( nChangeFrom==0 && sqlite3ResolveExprNames(&sNC, pWhere) ){
goto update_cleanup;
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Virtual tables must be handled separately */
if( IsVirtual(pTab) ){
updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
pWhere, onError);
goto update_cleanup;
}
#endif
/* Jump to labelBreak to abandon further processing of this UPDATE */
labelContinue = labelBreak = sqlite3VdbeMakeLabel(pParse);
/* Not an UPSERT. Normal processing. Begin by
** initialize the count of updated rows */
if( (db->flags&SQLITE_CountRows)!=0
&& !pParse->pTriggerTab
&& !pParse->nested
&& !pParse->bReturning
&& pUpsert==0
){
regRowCount = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
}
if( nChangeFrom==0 && HasRowid(pTab) ){
sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
iEph = pParse->nTab++;
addrOpen = sqlite3VdbeAddOp3(v, OP_OpenEphemeral, iEph, 0, regRowSet);
}else{
assert( pPk!=0 || HasRowid(pTab) );
nPk = pPk ? pPk->nKeyCol : 0;
iPk = pParse->nMem+1;
pParse->nMem += nPk;
pParse->nMem += nChangeFrom;
regKey = ++pParse->nMem;
if( pUpsert==0 ){
int nEphCol = nPk + nChangeFrom + (isView ? pTab->nCol : 0);
iEph = pParse->nTab++;
if( pPk ) sqlite3VdbeAddOp3(v, OP_Null, 0, iPk, iPk+nPk-1);
addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nEphCol);
if( pPk ){
KeyInfo *pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pPk);
if( pKeyInfo ){
pKeyInfo->nAllField = nEphCol;
sqlite3VdbeAppendP4(v, pKeyInfo, P4_KEYINFO);
}
}
if( nChangeFrom ){
updateFromSelect(
pParse, iEph, pPk, pChanges, pTabList, pWhere, pOrderBy, pLimit
);
#ifndef SQLITE_OMIT_SUBQUERY
if( isView ) iDataCur = iEph;
#endif
}
}
}
if( nChangeFrom ){
sqlite3MultiWrite(pParse);
eOnePass = ONEPASS_OFF;
nKey = nPk;
regKey = iPk;
}else{
if( pUpsert ){
/* If this is an UPSERT, then all cursors have already been opened by
** the outer INSERT and the data cursor should be pointing at the row
** that is to be updated. So bypass the code that searches for the
** row(s) to be updated.
*/
pWInfo = 0;
eOnePass = ONEPASS_SINGLE;
sqlite3ExprIfFalse(pParse, pWhere, labelBreak, SQLITE_JUMPIFNULL);
bFinishSeek = 0;
}else{
/* Begin the database scan.
**
** Do not consider a single-pass strategy for a multi-row update if
** there are any triggers or foreign keys to process, or rows may
** be deleted as a result of REPLACE conflict handling. Any of these
** things might disturb a cursor being used to scan through the table
** or index, causing a single-pass approach to malfunction. */
flags = WHERE_ONEPASS_DESIRED;
if( !pParse->nested && !pTrigger && !hasFK && !chngKey && !bReplace ){
flags |= WHERE_ONEPASS_MULTIROW;
}
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0,0,0,flags,iIdxCur);
if( pWInfo==0 ) goto update_cleanup;
/* A one-pass strategy that might update more than one row may not
** be used if any column of the index used for the scan is being
** updated. Otherwise, if there is an index on "b", statements like
** the following could create an infinite loop:
**
** UPDATE t1 SET b=b+1 WHERE b>?
**
** Fall back to ONEPASS_OFF if where.c has selected a ONEPASS_MULTI
** strategy that uses an index for which one or more columns are being
** updated. */
eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
bFinishSeek = sqlite3WhereUsesDeferredSeek(pWInfo);
if( eOnePass!=ONEPASS_SINGLE ){
sqlite3MultiWrite(pParse);
if( eOnePass==ONEPASS_MULTI ){
int iCur = aiCurOnePass[1];
if( iCur>=0 && iCur!=iDataCur && aToOpen[iCur-iBaseCur] ){
eOnePass = ONEPASS_OFF;
}
assert( iCur!=iDataCur || !HasRowid(pTab) );
}
}
}
if( HasRowid(pTab) ){
/* Read the rowid of the current row of the WHERE scan. In ONEPASS_OFF
** mode, write the rowid into the FIFO. In either of the one-pass modes,
** leave it in register regOldRowid. */
sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);
if( eOnePass==ONEPASS_OFF ){
aRegIdx[nAllIdx] = ++pParse->nMem;
sqlite3VdbeAddOp3(v, OP_Insert, iEph, regRowSet, regOldRowid);
}else{
if( ALWAYS(addrOpen) ) sqlite3VdbeChangeToNoop(v, addrOpen);
}
}else{
/* Read the PK of the current row into an array of registers. In
** ONEPASS_OFF mode, serialize the array into a record and store it in
** the ephemeral table. Or, in ONEPASS_SINGLE or MULTI mode, change
** the OP_OpenEphemeral instruction to a Noop (the ephemeral table
** is not required) and leave the PK fields in the array of registers. */
for(i=0; i<nPk; i++){
assert( pPk->aiColumn[i]>=0 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur,
pPk->aiColumn[i], iPk+i);
}
if( eOnePass ){
if( addrOpen ) sqlite3VdbeChangeToNoop(v, addrOpen);
nKey = nPk;
regKey = iPk;
}else{
sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey,
sqlite3IndexAffinityStr(db, pPk), nPk);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEph, regKey, iPk, nPk);
}
}
}
if( pUpsert==0 ){
if( nChangeFrom==0 && eOnePass!=ONEPASS_MULTI ){
sqlite3WhereEnd(pWInfo);
}
if( !isView ){
int addrOnce = 0;
/* Open every index that needs updating. */
if( eOnePass!=ONEPASS_OFF ){
if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0;
if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0;
}
if( eOnePass==ONEPASS_MULTI && (nIdx-(aiCurOnePass[1]>=0))>0 ){
addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
}
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, iBaseCur,
aToOpen, 0, 0);
if( addrOnce ){
sqlite3VdbeJumpHereOrPopInst(v, addrOnce);
}
}
/* Top of the update loop */
if( eOnePass!=ONEPASS_OFF ){
if( aiCurOnePass[0]!=iDataCur
&& aiCurOnePass[1]!=iDataCur
#ifdef SQLITE_ALLOW_ROWID_IN_VIEW
&& !isView
#endif
){
assert( pPk );
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey,nKey);
VdbeCoverage(v);
}
if( eOnePass!=ONEPASS_SINGLE ){
labelContinue = sqlite3VdbeMakeLabel(pParse);
}
sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
VdbeCoverageIf(v, pPk==0);
VdbeCoverageIf(v, pPk!=0);
}else if( pPk || nChangeFrom ){
labelContinue = sqlite3VdbeMakeLabel(pParse);
sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);
addrTop = sqlite3VdbeCurrentAddr(v);
if( nChangeFrom ){
if( !isView ){
if( pPk ){
for(i=0; i<nPk; i++){
sqlite3VdbeAddOp3(v, OP_Column, iEph, i, iPk+i);
}
sqlite3VdbeAddOp4Int(
v, OP_NotFound, iDataCur, labelContinue, iPk, nPk
); VdbeCoverage(v);
}else{
sqlite3VdbeAddOp2(v, OP_Rowid, iEph, regOldRowid);
sqlite3VdbeAddOp3(
v, OP_NotExists, iDataCur, labelContinue, regOldRowid
); VdbeCoverage(v);
}
}
}else{
sqlite3VdbeAddOp2(v, OP_RowData, iEph, regKey);
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey,0);
VdbeCoverage(v);
}
}else{
sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);
labelContinue = sqlite3VdbeMakeLabel(pParse);
addrTop = sqlite3VdbeAddOp2(v, OP_Rowid, iEph, regOldRowid);
VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
VdbeCoverage(v);
}
}
/* If the rowid value will change, set register regNewRowid to
** contain the new value. If the rowid is not being modified,
** then regNewRowid is the same register as regOldRowid, which is
** already populated. */
assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid );
if( chngRowid ){
assert( iRowidExpr>=0 );
if( nChangeFrom==0 ){
sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);
}else{
sqlite3VdbeAddOp3(v, OP_Column, iEph, iRowidExpr, regNewRowid);
}
sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v);
}
/* Compute the old pre-UPDATE content of the row being changed, if that
** information is needed */
if( chngPk || hasFK || pTrigger ){
u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0);
oldmask |= sqlite3TriggerColmask(pParse,
pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError
);
for(i=0; i<pTab->nCol; i++){
u32 colFlags = pTab->aCol[i].colFlags;
k = sqlite3TableColumnToStorage(pTab, i) + regOld;
if( oldmask==0xffffffff
|| (i<32 && (oldmask & MASKBIT32(i))!=0)
|| (colFlags & COLFLAG_PRIMKEY)!=0
){
testcase( oldmask!=0xffffffff && i==31 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, k);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, k);
}
}
if( chngRowid==0 && pPk==0 ){
sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid);
}
}
/* Populate the array of registers beginning at regNew with the new
** row data. This array is used to check constants, create the new
** table and index records, and as the values for any new.* references
** made by triggers.
**
** If there are one or more BEFORE triggers, then do not populate the
** registers associated with columns that are (a) not modified by
** this UPDATE statement and (b) not accessed by new.* references. The
** values for registers not modified by the UPDATE must be reloaded from
** the database after the BEFORE triggers are fired anyway (as the trigger
** may have modified them). So not loading those that are not going to
** be used eliminates some redundant opcodes.
*/
newmask = sqlite3TriggerColmask(
pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError
);
for(i=0, k=regNew; i<pTab->nCol; i++, k++){
if( i==pTab->iPKey ){
sqlite3VdbeAddOp2(v, OP_Null, 0, k);
}else if( (pTab->aCol[i].colFlags & COLFLAG_GENERATED)!=0 ){
if( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL ) k--;
}else{
j = aXRef[i];
if( j>=0 ){
if( nChangeFrom ){
int nOff = (isView ? pTab->nCol : nPk);
assert( eOnePass==ONEPASS_OFF );
sqlite3VdbeAddOp3(v, OP_Column, iEph, nOff+j, k);
}else{
sqlite3ExprCode(pParse, pChanges->a[j].pExpr, k);
}
}else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){
/* This branch loads the value of a column that will not be changed
** into a register. This is done if there are no BEFORE triggers, or
** if there are one or more BEFORE triggers that use this value via
** a new.* reference in a trigger program.
*/
testcase( i==31 );
testcase( i==32 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, k);
bFinishSeek = 0;
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, k);
}
}
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
if( pTab->tabFlags & TF_HasGenerated ){
testcase( pTab->tabFlags & TF_HasVirtual );
testcase( pTab->tabFlags & TF_HasStored );
sqlite3ComputeGeneratedColumns(pParse, regNew, pTab);
}
#endif
/* Fire any BEFORE UPDATE triggers. This happens before constraints are
** verified. One could argue that this is wrong.
*/
if( tmask&TRIGGER_BEFORE ){
sqlite3TableAffinity(v, pTab, regNew);
sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges,
TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue);
if( !isView ){
/* The row-trigger may have deleted the row being updated. In this
** case, jump to the next row. No updates or AFTER triggers are
** required. This behavior - what happens when the row being updated
** is deleted or renamed by a BEFORE trigger - is left undefined in the
** documentation.
*/
if( pPk ){
sqlite3VdbeAddOp4Int(v, OP_NotFound,iDataCur,labelContinue,regKey,nKey);
VdbeCoverage(v);
}else{
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue,regOldRowid);
VdbeCoverage(v);
}
/* After-BEFORE-trigger-reload-loop:
** If it did not delete it, the BEFORE trigger may still have modified
** some of the columns of the row being updated. Load the values for
** all columns not modified by the update statement into their registers
** in case this has happened. Only unmodified columns are reloaded.
** The values computed for modified columns use the values before the
** BEFORE trigger runs. See test case trigger1-18.0 (added 2018-04-26)
** for an example.
*/
for(i=0, k=regNew; i<pTab->nCol; i++, k++){
if( pTab->aCol[i].colFlags & COLFLAG_GENERATED ){
if( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL ) k--;
}else if( aXRef[i]<0 && i!=pTab->iPKey ){
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, k);
}
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
if( pTab->tabFlags & TF_HasGenerated ){
testcase( pTab->tabFlags & TF_HasVirtual );
testcase( pTab->tabFlags & TF_HasStored );
sqlite3ComputeGeneratedColumns(pParse, regNew, pTab);
}
#endif
}
}
if( !isView ){
/* Do constraint checks. */
assert( regOldRowid>0 );
sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace,
aXRef, 0);
/* If REPLACE conflict handling may have been used, or if the PK of the
** row is changing, then the GenerateConstraintChecks() above may have
** moved cursor iDataCur. Reseek it. */
if( bReplace || chngKey ){
if( pPk ){
sqlite3VdbeAddOp4Int(v, OP_NotFound,iDataCur,labelContinue,regKey,nKey);
}else{
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue,regOldRowid);
}
VdbeCoverage(v);
}
/* Do FK constraint checks. */
if( hasFK ){
sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey);
}
/* Delete the index entries associated with the current record. */
sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1);
/* We must run the OP_FinishSeek opcode to resolve a prior
** OP_DeferredSeek if there is any possibility that there have been
** no OP_Column opcodes since the OP_DeferredSeek was issued. But
** we want to avoid the OP_FinishSeek if possible, as running it
** costs CPU cycles. */
if( bFinishSeek ){
sqlite3VdbeAddOp1(v, OP_FinishSeek, iDataCur);
}
/* If changing the rowid value, or if there are foreign key constraints
** to process, delete the old record. Otherwise, add a noop OP_Delete
** to invoke the pre-update hook.
**
** That (regNew==regnewRowid+1) is true is also important for the
** pre-update hook. If the caller invokes preupdate_new(), the returned
** value is copied from memory cell (regNewRowid+1+iCol), where iCol
** is the column index supplied by the user.
*/
assert( regNew==regNewRowid+1 );
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
sqlite3VdbeAddOp3(v, OP_Delete, iDataCur,
OPFLAG_ISUPDATE | ((hasFK>1 || chngKey) ? 0 : OPFLAG_ISNOOP),
regNewRowid
);
if( eOnePass==ONEPASS_MULTI ){
assert( hasFK==0 && chngKey==0 );
sqlite3VdbeChangeP5(v, OPFLAG_SAVEPOSITION);
}
if( !pParse->nested ){
sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
}
#else
if( hasFK>1 || chngKey ){
sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
}
#endif
if( hasFK ){
sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey);
}
/* Insert the new index entries and the new record. */
sqlite3CompleteInsertion(
pParse, pTab, iDataCur, iIdxCur, regNewRowid, aRegIdx,
OPFLAG_ISUPDATE | (eOnePass==ONEPASS_MULTI ? OPFLAG_SAVEPOSITION : 0),
0, 0
);
/* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
** handle rows (possibly in other tables) that refer via a foreign key
** to the row just updated. */
if( hasFK ){
sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey);
}
}
/* Increment the row counter
*/
if( regRowCount ){
sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
}
sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges,
TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue);
/* Repeat the above with the next record to be updated, until
** all record selected by the WHERE clause have been updated.
*/
if( eOnePass==ONEPASS_SINGLE ){
/* Nothing to do at end-of-loop for a single-pass */
}else if( eOnePass==ONEPASS_MULTI ){
sqlite3VdbeResolveLabel(v, labelContinue);
sqlite3WhereEnd(pWInfo);
}else{
sqlite3VdbeResolveLabel(v, labelContinue);
sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v);
}
sqlite3VdbeResolveLabel(v, labelBreak);
/* Update the sqlite_sequence table by storing the content of the
** maximum rowid counter values recorded while inserting into
** autoincrement tables.
*/
if( pParse->nested==0 && pParse->pTriggerTab==0 && pUpsert==0 ){
sqlite3AutoincrementEnd(pParse);
}
/*
** Return the number of rows that were changed, if we are tracking
** that information.
*/
if( regRowCount ){
sqlite3CodeChangeCount(v, regRowCount, "rows updated");
}
update_cleanup:
sqlite3AuthContextPop(&sContext);
sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */
sqlite3SrcListDelete(db, pTabList);
sqlite3ExprListDelete(db, pChanges);
sqlite3ExprDelete(db, pWhere);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT)
sqlite3ExprListDelete(db, pOrderBy);
sqlite3ExprDelete(db, pLimit);
#endif
return;
}
/* Make sure "isView" and other macros defined above are undefined. Otherwise
** they may interfere with compilation of other functions in this file
** (or in another file, if this file becomes part of the amalgamation). */
#ifdef isView
#undef isView
#endif
#ifdef pTrigger
#undef pTrigger
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Generate code for an UPDATE of a virtual table.
**
** There are two possible strategies - the default and the special
** "onepass" strategy. Onepass is only used if the virtual table
** implementation indicates that pWhere may match at most one row.
**
** The default strategy is to create an ephemeral table that contains
** for each row to be changed:
**
** (A) The original rowid of that row.
** (B) The revised rowid for the row.
** (C) The content of every column in the row.
**
** Then loop through the contents of this ephemeral table executing a
** VUpdate for each row. When finished, drop the ephemeral table.
**
** The "onepass" strategy does not use an ephemeral table. Instead, it
** stores the same values (A, B and C above) in a register array and
** makes a single invocation of VUpdate.
*/
static void updateVirtualTable(
Parse *pParse, /* The parsing context */
SrcList *pSrc, /* The virtual table to be modified */
Table *pTab, /* The virtual table */
ExprList *pChanges, /* The columns to change in the UPDATE statement */
Expr *pRowid, /* Expression used to recompute the rowid */
int *aXRef, /* Mapping from columns of pTab to entries in pChanges */
Expr *pWhere, /* WHERE clause of the UPDATE statement */
int onError /* ON CONFLICT strategy */
){
Vdbe *v = pParse->pVdbe; /* Virtual machine under construction */
int ephemTab; /* Table holding the result of the SELECT */
int i; /* Loop counter */
sqlite3 *db = pParse->db; /* Database connection */
const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);
WhereInfo *pWInfo = 0;
int nArg = 2 + pTab->nCol; /* Number of arguments to VUpdate */
int regArg; /* First register in VUpdate arg array */
int regRec; /* Register in which to assemble record */
int regRowid; /* Register for ephem table rowid */
int iCsr = pSrc->a[0].iCursor; /* Cursor used for virtual table scan */
int aDummy[2]; /* Unused arg for sqlite3WhereOkOnePass() */
int eOnePass; /* True to use onepass strategy */
int addr; /* Address of OP_OpenEphemeral */
/* Allocate nArg registers in which to gather the arguments for VUpdate. Then
** create and open the ephemeral table in which the records created from
** these arguments will be temporarily stored. */
assert( v );
ephemTab = pParse->nTab++;
addr= sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, nArg);
regArg = pParse->nMem + 1;
pParse->nMem += nArg;
if( pSrc->nSrc>1 ){
Index *pPk = 0;
Expr *pRow;
ExprList *pList;
if( HasRowid(pTab) ){
if( pRowid ){
pRow = sqlite3ExprDup(db, pRowid, 0);
}else{
pRow = sqlite3PExpr(pParse, TK_ROW, 0, 0);
}
}else{
i16 iPk; /* PRIMARY KEY column */
pPk = sqlite3PrimaryKeyIndex(pTab);
assert( pPk!=0 );
assert( pPk->nKeyCol==1 );
iPk = pPk->aiColumn[0];
if( aXRef[iPk]>=0 ){
pRow = sqlite3ExprDup(db, pChanges->a[aXRef[iPk]].pExpr, 0);
}else{
pRow = exprRowColumn(pParse, iPk);
}
}
pList = sqlite3ExprListAppend(pParse, 0, pRow);
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]>=0 ){
pList = sqlite3ExprListAppend(pParse, pList,
sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr, 0)
);
}else{
pList = sqlite3ExprListAppend(pParse, pList, exprRowColumn(pParse, i));
}
}
updateFromSelect(pParse, ephemTab, pPk, pList, pSrc, pWhere, 0, 0);
sqlite3ExprListDelete(db, pList);
eOnePass = ONEPASS_OFF;
}else{
regRec = ++pParse->nMem;
regRowid = ++pParse->nMem;
/* Start scanning the virtual table */
pWInfo = sqlite3WhereBegin(
pParse, pSrc, pWhere, 0, 0, 0, WHERE_ONEPASS_DESIRED, 0
);
if( pWInfo==0 ) return;
/* Populate the argument registers. */
for(i=0; i<pTab->nCol; i++){
assert( (pTab->aCol[i].colFlags & COLFLAG_GENERATED)==0 );
if( aXRef[i]>=0 ){
sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);
}else{
sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i);
sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG);/* For sqlite3_vtab_nochange() */
}
}
if( HasRowid(pTab) ){
sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg);
if( pRowid ){
sqlite3ExprCode(pParse, pRowid, regArg+1);
}else{
sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg+1);
}
}else{
Index *pPk; /* PRIMARY KEY index */
i16 iPk; /* PRIMARY KEY column */
pPk = sqlite3PrimaryKeyIndex(pTab);
assert( pPk!=0 );
assert( pPk->nKeyCol==1 );
iPk = pPk->aiColumn[0];
sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, iPk, regArg);
sqlite3VdbeAddOp2(v, OP_SCopy, regArg+2+iPk, regArg+1);
}
eOnePass = sqlite3WhereOkOnePass(pWInfo, aDummy);
/* There is no ONEPASS_MULTI on virtual tables */
assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE );
if( eOnePass ){
/* If using the onepass strategy, no-op out the OP_OpenEphemeral coded
** above. */
sqlite3VdbeChangeToNoop(v, addr);
sqlite3VdbeAddOp1(v, OP_Close, iCsr);
}else{
/* Create a record from the argument register contents and insert it into
** the ephemeral table. */
sqlite3MultiWrite(pParse);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regArg, nArg, regRec);
#if defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_NULL_TRIM)
/* Signal an assert() within OP_MakeRecord that it is allowed to
** accept no-change records with serial_type 10 */
sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG_MAGIC);
#endif
sqlite3VdbeAddOp2(v, OP_NewRowid, ephemTab, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, ephemTab, regRec, regRowid);
}
}
if( eOnePass==ONEPASS_OFF ){
/* End the virtual table scan */
if( pSrc->nSrc==1 ){
sqlite3WhereEnd(pWInfo);
}
/* Begin scannning through the ephemeral table. */
addr = sqlite3VdbeAddOp1(v, OP_Rewind, ephemTab); VdbeCoverage(v);
/* Extract arguments from the current row of the ephemeral table and
** invoke the VUpdate method. */
for(i=0; i<nArg; i++){
sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i, regArg+i);
}
}
sqlite3VtabMakeWritable(pParse, pTab);
sqlite3VdbeAddOp4(v, OP_VUpdate, 0, nArg, regArg, pVTab, P4_VTAB);
sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
sqlite3MayAbort(pParse);
/* End of the ephemeral table scan. Or, if using the onepass strategy,
** jump to here if the scan visited zero rows. */
if( eOnePass==ONEPASS_OFF ){
sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addr);
sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
}else{
sqlite3WhereEnd(pWInfo);
}
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */