DBD-SQLite2
view release on metacpan or search on metacpan
/*
** 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 INSERT statements in SQLite.
**
** $Id: insert.c,v 1.1.1.1 2004/08/08 15:03:57 matt Exp $
*/
#include "sqliteInt.h"
/*
** This routine is call to handle SQL of the following forms:
**
** insert into TABLE (IDLIST) values(EXPRLIST)
** insert into TABLE (IDLIST) select
**
** The IDLIST following the table name is always optional. If omitted,
** then a list of all columns for the table is substituted. The IDLIST
** appears in the pColumn parameter. pColumn is NULL if IDLIST is omitted.
**
** The pList parameter holds EXPRLIST in the first form of the INSERT
** statement above, and pSelect is NULL. For the second form, pList is
** NULL and pSelect is a pointer to the select statement used to generate
** data for the insert.
**
** The code generated follows one of three templates. For a simple
** select with data coming from a VALUES clause, the code executes
** once straight down through. The template looks like this:
**
** open write cursor to <table> and its indices
** puts VALUES clause expressions onto the stack
** write the resulting record into <table>
** cleanup
**
** If the statement is of the form
**
** INSERT INTO <table> SELECT ...
**
** And the SELECT clause does not read from <table> at any time, then
** the generated code follows this template:
**
** goto B
** A: setup for the SELECT
** loop over the tables in the SELECT
** gosub C
** end loop
** cleanup after the SELECT
** goto D
** B: open write cursor to <table> and its indices
** goto A
** C: insert the select result into <table>
** return
** D: cleanup
**
** The third template is used if the insert statement takes its
** values from a SELECT but the data is being inserted into a table
** that is also read as part of the SELECT. In the third form,
** we have to use a intermediate table to store the results of
** the select. The template is like this:
**
** goto B
** A: setup for the SELECT
** loop over the tables in the SELECT
** gosub C
** end loop
** cleanup after the SELECT
** goto D
** C: insert the select result into the intermediate table
** return
** B: open a cursor to an intermediate table
** goto A
** D: open write cursor to <table> and its indices
** loop over the intermediate table
** transfer values form intermediate table into <table>
** end the loop
** cleanup
*/
void sqliteInsert(
Parse *pParse, /* Parser context */
SrcList *pTabList, /* Name of table into which we are inserting */
ExprList *pList, /* List of values to be inserted */
Select *pSelect, /* A SELECT statement to use as the data source */
IdList *pColumn, /* Column names corresponding to IDLIST. */
int onError /* How to handle constraint errors */
){
Table *pTab; /* The table to insert into */
char *zTab; /* Name of the table into which we are inserting */
const char *zDb; /* Name of the database holding this table */
int i, j, idx; /* Loop counters */
Vdbe *v; /* Generate code into this virtual machine */
Index *pIdx; /* For looping over indices of the table */
int nColumn; /* Number of columns in the data */
int base; /* VDBE Cursor number for pTab */
int iCont, iBreak; /* Beginning and end of the loop over srcTab */
sqlite *db; /* The main database structure */
int keyColumn = -1; /* Column that is the INTEGER PRIMARY KEY */
int endOfLoop; /* Label for the end of the insertion loop */
int useTempTable; /* Store SELECT results in intermediate table */
int srcTab; /* Data comes from this temporary cursor if >=0 */
int iSelectLoop; /* Address of code that implements the SELECT */
int iCleanup; /* Address of the cleanup code */
int iInsertBlock; /* Address of the subroutine used to insert data */
int iCntMem; /* Memory cell used for the row counter */
int isView; /* True if attempting to insert into a view */
int row_triggers_exist = 0; /* True if there are FOR EACH ROW triggers */
int before_triggers; /* True if there are BEFORE triggers */
int after_triggers; /* True if there are AFTER triggers */
int newIdx = -1; /* Cursor for the NEW table */
if( pParse->nErr || sqlite_malloc_failed ) goto insert_cleanup;
db = pParse->db;
/* Locate the table into which we will be inserting new information.
*/
assert( pTabList->nSrc==1 );
zTab = pTabList->a[0].zName;
if( zTab==0 ) goto insert_cleanup;
pTab = sqliteSrcListLookup(pParse, pTabList);
if( pTab==0 ){
goto insert_cleanup;
}
assert( pTab->iDb<db->nDb );
zDb = db->aDb[pTab->iDb].zName;
if( sqliteAuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb) ){
goto insert_cleanup;
}
/* Ensure that:
* (a) the table is not read-only,
* (b) that if it is a view then ON INSERT triggers exist
*/
before_triggers = sqliteTriggersExist(pParse, pTab->pTrigger, TK_INSERT,
TK_BEFORE, TK_ROW, 0);
after_triggers = sqliteTriggersExist(pParse, pTab->pTrigger, TK_INSERT,
TK_AFTER, TK_ROW, 0);
row_triggers_exist = before_triggers || after_triggers;
isView = pTab->pSelect!=0;
if( sqliteIsReadOnly(pParse, pTab, before_triggers) ){
goto insert_cleanup;
}
if( pTab==0 ) goto insert_cleanup;
/* If pTab is really a view, make sure it has been initialized.
*/
if( isView && sqliteViewGetColumnNames(pParse, pTab) ){
goto insert_cleanup;
}
/* Allocate a VDBE
*/
v = sqliteGetVdbe(pParse);
if( v==0 ) goto insert_cleanup;
sqliteBeginWriteOperation(pParse, pSelect || row_triggers_exist, pTab->iDb);
/* if there are row triggers, allocate a temp table for new.* references. */
if( row_triggers_exist ){
newIdx = pParse->nTab++;
}
** value is omitted unless we are doing an UPDATE that involves a
** change to the record number.
**
** 2. The recno of the row after the update.
**
** 3. The data in the first column of the entry after the update.
**
** i. Data from middle columns...
**
** N. The data in the last column of the entry after the update.
**
** The old recno shown as entry (1) above is omitted unless both isUpdate
** and recnoChng are 1. isUpdate is true for UPDATEs and false for
** INSERTs and recnoChng is true if the record number is being changed.
**
** The code generated by this routine pushes additional entries onto
** the stack which are the keys for new index entries for the new record.
** The order of index keys is the same as the order of the indices on
** the pTable->pIndex list. A key is only created for index i if
** aIdxUsed!=0 and aIdxUsed[i]!=0.
**
** This routine also generates code to check constraints. NOT NULL,
** CHECK, and UNIQUE constraints are all checked. If a constraint fails,
** then the appropriate action is performed. There are five possible
** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
**
** Constraint type Action What Happens
** --------------- ---------- ----------------------------------------
** any ROLLBACK The current transaction is rolled back and
** sqlite_exec() returns immediately with a
** return code of SQLITE_CONSTRAINT.
**
** any ABORT Back out changes from the current command
** only (do not do a complete rollback) then
** cause sqlite_exec() to return immediately
** with SQLITE_CONSTRAINT.
**
** any FAIL Sqlite_exec() returns immediately with a
** return code of SQLITE_CONSTRAINT. The
** transaction is not rolled back and any
** prior changes are retained.
**
** any IGNORE The record number and data is popped from
** the stack and there is an immediate jump
** to label ignoreDest.
**
** NOT NULL REPLACE The NULL value is replace by the default
** value for that column. If the default value
** is NULL, the action is the same as ABORT.
**
** UNIQUE REPLACE The other row that conflicts with the row
** being inserted is removed.
**
** CHECK REPLACE Illegal. The results in an exception.
**
** Which action to take is determined by the overrideError parameter.
** Or if overrideError==OE_Default, then the pParse->onError parameter
** is used. Or if pParse->onError==OE_Default then the onError value
** for the constraint is used.
**
** The calling routine must open a read/write cursor for pTab with
** cursor number "base". All indices of pTab must also have open
** read/write cursors with cursor number base+i for the i-th cursor.
** Except, if there is no possibility of a REPLACE action then
** cursors do not need to be open for indices where aIdxUsed[i]==0.
**
** If the isUpdate flag is true, it means that the "base" cursor is
** initially pointing to an entry that is being updated. The isUpdate
** flag causes extra code to be generated so that the "base" cursor
** is still pointing at the same entry after the routine returns.
** Without the isUpdate flag, the "base" cursor might be moved.
*/
void sqliteGenerateConstraintChecks(
Parse *pParse, /* The parser context */
Table *pTab, /* the table into which we are inserting */
int base, /* Index of a read/write cursor pointing at pTab */
char *aIdxUsed, /* Which indices are used. NULL means all are used */
int recnoChng, /* True if the record number will change */
int isUpdate, /* True for UPDATE, False for INSERT */
int overrideError, /* Override onError to this if not OE_Default */
int ignoreDest /* Jump to this label on an OE_Ignore resolution */
){
int i;
Vdbe *v;
int nCol;
int onError;
int addr;
int extra;
int iCur;
Index *pIdx;
int seenReplace = 0;
int jumpInst1, jumpInst2;
int contAddr;
int hasTwoRecnos = (isUpdate && recnoChng);
v = sqliteGetVdbe(pParse);
assert( v!=0 );
assert( pTab->pSelect==0 ); /* This table is not a VIEW */
nCol = pTab->nCol;
/* Test all NOT NULL constraints.
*/
for(i=0; i<nCol; i++){
if( i==pTab->iPKey ){
continue;
}
onError = pTab->aCol[i].notNull;
if( onError==OE_None ) continue;
if( overrideError!=OE_Default ){
onError = overrideError;
}else if( pParse->db->onError!=OE_Default ){
onError = pParse->db->onError;
}else if( onError==OE_Default ){
onError = OE_Abort;
}
if( onError==OE_Replace && pTab->aCol[i].zDflt==0 ){
onError = OE_Abort;
}
sqliteVdbeAddOp(v, OP_Dup, nCol-1-i, 1);
addr = sqliteVdbeAddOp(v, OP_NotNull, 1, 0);
switch( onError ){
case OE_Rollback:
case OE_Abort:
case OE_Fail: {
char *zMsg = 0;
sqliteVdbeAddOp(v, OP_Halt, SQLITE_CONSTRAINT, onError);
sqliteSetString(&zMsg, pTab->zName, ".", pTab->aCol[i].zName,
" may not be NULL", (char*)0);
sqliteVdbeChangeP3(v, -1, zMsg, P3_DYNAMIC);
break;
}
case OE_Ignore: {
sqliteVdbeAddOp(v, OP_Pop, nCol+1+hasTwoRecnos, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, ignoreDest);
break;
}
n1 = strlen(zErrMsg);
for(j=0; j<pIdx->nColumn && n1<sizeof(zErrMsg)-30; j++){
char *zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
n2 = strlen(zCol);
if( j>0 ){
strcpy(&zErrMsg[n1], ", ");
n1 += 2;
}
if( n1+n2>sizeof(zErrMsg)-30 ){
strcpy(&zErrMsg[n1], "...");
n1 += 3;
break;
}else{
strcpy(&zErrMsg[n1], zCol);
n1 += n2;
}
}
strcpy(&zErrMsg[n1],
pIdx->nColumn>1 ? " are not unique" : " is not unique");
sqliteVdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, onError, zErrMsg, 0);
break;
}
case OE_Ignore: {
assert( seenReplace==0 );
sqliteVdbeAddOp(v, OP_Pop, nCol+extra+3+hasTwoRecnos, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, ignoreDest);
break;
}
case OE_Replace: {
sqliteGenerateRowDelete(pParse->db, v, pTab, base, 0);
if( isUpdate ){
sqliteVdbeAddOp(v, OP_Dup, nCol+extra+1+hasTwoRecnos, 1);
sqliteVdbeAddOp(v, OP_MoveTo, base, 0);
}
seenReplace = 1;
break;
}
default: assert(0);
}
contAddr = sqliteVdbeCurrentAddr(v);
#if NULL_DISTINCT_FOR_UNIQUE
sqliteVdbeChangeP2(v, jumpInst1, contAddr);
#endif
sqliteVdbeChangeP2(v, jumpInst2, contAddr);
}
}
/*
** This routine generates code to finish the INSERT or UPDATE operation
** that was started by a prior call to sqliteGenerateConstraintChecks.
** The stack must contain keys for all active indices followed by data
** and the recno for the new entry. This routine creates the new
** entries in all indices and in the main table.
**
** The arguments to this routine should be the same as the first six
** arguments to sqliteGenerateConstraintChecks.
*/
void sqliteCompleteInsertion(
Parse *pParse, /* The parser context */
Table *pTab, /* the table into which we are inserting */
int base, /* Index of a read/write cursor pointing at pTab */
char *aIdxUsed, /* Which indices are used. NULL means all are used */
int recnoChng, /* True if the record number will change */
int isUpdate, /* True for UPDATE, False for INSERT */
int newIdx /* Index of NEW table for triggers. -1 if none */
){
int i;
Vdbe *v;
int nIdx;
Index *pIdx;
v = sqliteGetVdbe(pParse);
assert( v!=0 );
assert( pTab->pSelect==0 ); /* This table is not a VIEW */
for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
for(i=nIdx-1; i>=0; i--){
if( aIdxUsed && aIdxUsed[i]==0 ) continue;
sqliteVdbeAddOp(v, OP_IdxPut, base+i+1, 0);
}
sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
if( newIdx>=0 ){
sqliteVdbeAddOp(v, OP_Dup, 1, 0);
sqliteVdbeAddOp(v, OP_Dup, 1, 0);
sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);
}
sqliteVdbeAddOp(v, OP_PutIntKey, base,
(pParse->trigStack?0:OPFLAG_NCHANGE) |
(isUpdate?0:OPFLAG_LASTROWID) | OPFLAG_CSCHANGE);
if( isUpdate && recnoChng ){
sqliteVdbeAddOp(v, OP_Pop, 1, 0);
}
}
/*
** Generate code that will open write cursors for a table and for all
** indices of that table. The "base" parameter is the cursor number used
** for the table. Indices are opened on subsequent cursors.
**
** Return the total number of cursors opened. This is always at least
** 1 (for the main table) plus more for each cursor.
*/
int sqliteOpenTableAndIndices(Parse *pParse, Table *pTab, int base){
int i;
Index *pIdx;
Vdbe *v = sqliteGetVdbe(pParse);
assert( v!=0 );
sqliteVdbeAddOp(v, OP_Integer, pTab->iDb, 0);
sqliteVdbeOp3(v, OP_OpenWrite, base, pTab->tnum, pTab->zName, P3_STATIC);
for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
sqliteVdbeAddOp(v, OP_Integer, pIdx->iDb, 0);
sqliteVdbeOp3(v, OP_OpenWrite, i+base, pIdx->tnum, pIdx->zName, P3_STATIC);
}
return i;
}
( run in 1.588 second using v1.01-cache-2.11-cpan-13bb782fe5a )