SQLite

**    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 used to generate VDBE code
** that implements the ALTER TABLE command.
**
** $Id: alter.c,v 1.54 2009/02/28 10:47:42 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The code in this file only exists if we are not omitting the
** ALTER TABLE logic from the build.
*/

  /* If the table is not located in the temp-db (in which case NULL is 
  ** returned, loop through the tables list of triggers. For each trigger
  ** that is not part of the temp-db schema, add a clause to the WHERE 
  ** expression being built up in zWhere.
  */
  if( pTab->pSchema!=pTempSchema ){
    sqlite3 *db = pParse->db;
    for(pTrig=sqlite3TriggerList(pParse, pTab); pTrig; pTrig=pTrig->pNext){
      if( pTrig->pSchema==pTempSchema ){
        if( !zWhere ){
          zWhere = sqlite3MPrintf(db, "name=%Q", pTrig->name);
        }else{
          tmp = zWhere;
          zWhere = sqlite3MPrintf(db, "%s OR name=%Q", zWhere, pTrig->name);
          sqlite3DbFree(db, tmp);

  if( !v ) return;
  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  assert( iDb>=0 );

#ifndef SQLITE_OMIT_TRIGGER
  /* Drop any table triggers from the internal schema. */
  for(pTrig=sqlite3TriggerList(pParse, pTab); pTrig; pTrig=pTrig->pNext){
    int iTrigDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
    assert( iTrigDb==iDb || iTrigDb==1 );
    sqlite3VdbeAddOp4(v, OP_DropTrigger, iTrigDb, 0, 0, pTrig->name, 0);
  }
#endif

  /* Drop the table and index from the internal schema */

/*
** 2005 July 8
**
** 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 code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.51 2009/02/28 10:47:42 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.

    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);

    /* Store the results.  
    **
    ** The result is a single row of the sqlite_stat1 table.  The first
    ** two columns are the names of the table and index.  The third column
    ** is a string composed of a list of integer statistics about the
    ** index.  The first integer in the list is the total number of entries
    ** in the index.  There is one additional integer in the list for each
    ** column of the table.  This additional integer is a guess of how many
    ** rows of the table the index will select.  If D is the count of distinct
    ** values and K is the total number of rows, then the integer is computed
    ** as:
    **
    **        I = (K+D-1)/D

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.521 2009/02/28 10:47:42 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
*/

    }
#endif

    /* Drop all triggers associated with the table being dropped. Code
    ** is generated to remove entries from sqlite_master and/or
    ** sqlite_temp_master if required.
    */
    pTrigger = sqlite3TriggerList(pParse, pTab);
    while( pTrigger ){
      assert( pTrigger->pSchema==pTab->pSchema || 
          pTrigger->pSchema==db->aDb[1].pSchema );
      sqlite3DropTriggerPtr(pParse, pTrigger);
      pTrigger = pTrigger->pNext;
    }

**    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
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.196 2009/02/28 10:47:42 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.

  NameContext sNC;       /* Name context to resolve expressions in */
  int iDb;               /* Database number */
  int memCnt = -1;       /* Memory cell used for change counting */
  int rcauth;            /* Value returned by authorization callback */

#ifndef SQLITE_OMIT_TRIGGER
  int isView;                  /* True if attempting to delete from a view */
  Trigger *pTrigger;           /* List of table triggers, if required */
#endif
  int iBeginAfterTrigger = 0;  /* Address of after trigger program */
  int iEndAfterTrigger = 0;    /* Exit of after trigger program */
  int iBeginBeforeTrigger = 0; /* Address of before trigger program */
  int iEndBeforeTrigger = 0;   /* Exit of before trigger program */
  u32 old_col_mask = 0;        /* Mask of OLD.* columns in use */

  pTab = sqlite3SrcListLookup(pParse, pTabList);
  if( pTab==0 )  goto delete_from_cleanup;

  /* Figure out if we have any triggers and if the table being
  ** deleted from is a view
  */
#ifndef SQLITE_OMIT_TRIGGER
  pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
  isView = pTab->pSelect!=0;
#else
# define pTrigger 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif

  if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){
    goto delete_from_cleanup;
  }
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iDb<db->nDb );
  zDb = db->aDb[iDb].zName;
  rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb);
  assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
  if( rcauth==SQLITE_DENY ){
    goto delete_from_cleanup;
  }
  assert(!isView || pTrigger);

  /* If pTab is really a view, make sure it has been initialized.
  */
  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto delete_from_cleanup;
  }

  /* Allocate a cursor used to store the old.* data for a trigger.
  */
  if( pTrigger ){ 
    oldIdx = pParse->nTab++;
  }

  /* Assign  cursor number to the table and all its indices.
  */
  assert( pTabList->nSrc==1 );
  iCur = pTabList->a[0].iCursor = pParse->nTab++;

  /* Begin generating code.
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ){
    goto delete_from_cleanup;
  }
  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
  sqlite3BeginWriteOperation(pParse, (pTrigger?1:0), iDb);

  if( pTrigger ){
    int orconf = ((pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
    int iGoto = sqlite3VdbeAddOp0(v, OP_Goto);
    addr = sqlite3VdbeMakeLabel(v);

    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
    (void)sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0, 
        TRIGGER_BEFORE, pTab, -1, oldIdx, orconf, addr, &old_col_mask, 0);
    iEndBeforeTrigger = sqlite3VdbeAddOp0(v, OP_Goto);

    iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
    (void)sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0, 
        TRIGGER_AFTER, pTab, -1, oldIdx, orconf, addr, &old_col_mask, 0);
    iEndAfterTrigger = sqlite3VdbeAddOp0(v, OP_Goto);

    sqlite3VdbeJumpHere(v, iGoto);
  }

  /* If we are trying to delete from a view, realize that view into
  ** a ephemeral table.

  }

#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
  /* Special case: A DELETE without a WHERE clause deletes everything.
  ** It is easier just to erase the whole table.  Note, however, that
  ** this means that the row change count will be incorrect.
  */
  if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab) ){
    assert( !isView );
    sqlite3VdbeAddOp3(v, OP_Clear, pTab->tnum, iDb, memCnt);
    if( !pParse->nested ){
      sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
    }
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pIdx->pSchema==pTab->pSchema );

    if( db->flags & SQLITE_CountRows ){
      sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
    }
    sqlite3WhereEnd(pWInfo);

    /* Open the pseudo-table used to store OLD if there are triggers.
    */
    if( pTrigger ){
      sqlite3VdbeAddOp3(v, OP_OpenPseudo, oldIdx, 0, pTab->nCol);
    }

    /* Delete every item whose key was written to the list during the
    ** database scan.  We have to delete items after the scan is complete
    ** because deleting an item can change the scan order.
    */
    end = sqlite3VdbeMakeLabel(v);

    if( !isView ){
      /* Open cursors for the table we are deleting from and 
      ** all its indices.
      */
      sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);
    }

    /* This is the beginning of the delete loop. If a trigger encounters
    ** an IGNORE constraint, it jumps back to here.
    */
    if( pTrigger ){
      sqlite3VdbeResolveLabel(v, addr);
    }
    addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, iRowid);

    if( pTrigger ){
      int iData = ++pParse->nMem;   /* For storing row data of OLD table */

      /* If the record is no longer present in the table, jump to the
      ** next iteration of the loop through the contents of the fifo.
      */
      sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, iRowid);

        sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, pParse->nested==0);
      }
    }

    /* If there are row triggers, close all cursors then invoke
    ** the AFTER triggers
    */
    if( pTrigger ){
      /* Jump back and run the AFTER triggers */
      sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger);
      sqlite3VdbeJumpHere(v, iEndAfterTrigger);
    }

    /* End of the delete loop */
    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);

**    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 1.260 2009/02/28 10:47:42 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Set P4 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:

  int regRecord;        /* Holds the assemblied row record */
  int regEof = 0;       /* Register recording end of SELECT data */
  int *aRegIdx = 0;     /* One register allocated to each index */


#ifndef SQLITE_OMIT_TRIGGER
  int isView;                 /* True if attempting to insert into a view */
  Trigger *pTrigger;          /* List of triggers on pTab, if required */
  int tmask;                  /* Mask of trigger times */
#endif

  db = pParse->db;
  memset(&dest, 0, sizeof(dest));
  if( pParse->nErr || db->mallocFailed ){
    goto insert_cleanup;
  }

    goto insert_cleanup;
  }

  /* Figure out if we have any triggers and if the table being
  ** inserted into is a view
  */
#ifndef SQLITE_OMIT_TRIGGER
  pTrigger = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0, &tmask);
  isView = pTab->pSelect!=0;
#else
# define pTrigger 0
# define tmask 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
  assert( (pTrigger && tmask) || (pTrigger==0 && tmask==0) );

  /* Ensure that:
  *  (a) the table is not read-only, 
  *  (b) that if it is a view then ON INSERT triggers exist
  */
  if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
    goto insert_cleanup;
  }
  assert( pTab!=0 );

  /* If pTab is really a view, make sure it has been initialized.
  ** ViewGetColumnNames() is a no-op if pTab is not a view (or virtual 
  ** module table).
  */
  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto insert_cleanup;
  }

  /* Allocate a VDBE
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) goto insert_cleanup;
  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
  sqlite3BeginWriteOperation(pParse, pSelect || pTrigger, iDb);

  /* if there are row triggers, allocate a temp table for new.* references. */
  if( pTrigger ){
    newIdx = pParse->nTab++;
  }

#ifndef SQLITE_OMIT_XFER_OPT
  /* If the statement is of the form
  **
  **       INSERT INTO <table1> SELECT * FROM <table2>;
  **
  ** Then special optimizations can be applied that make the transfer
  ** very fast and which reduce fragmentation of indices.
  **
  ** This is the 2nd template.
  */
  if( pColumn==0 && xferOptimization(pParse, pTab, pSelect, onError, iDb) ){
    assert( !pTrigger );
    assert( pList==0 );
    goto insert_cleanup;
  }
#endif /* SQLITE_OMIT_XFER_OPT */

  /* If this is an AUTOINCREMENT table, look up the sequence number in the
  ** sqlite_sequence table and store it in memory cell regAutoinc.

    ** FALSE if each* row of the SELECT can be written directly into
    ** the destination table (template 3).
    **
    ** A temp table must be used if the table being updated is also one
    ** of the tables being read by the SELECT statement.  Also use a 
    ** temp table in the case of row triggers.
    */
    if( pTrigger || readsTable(v, addrSelect, iDb, pTab) ){
      useTempTable = 1;
    }

    if( useTempTable ){
      /* Invoke the coroutine to extract information from the SELECT
      ** and add it to a transient table srcTab.  The code generated
      ** here is from the 4th template:

  */
  if( pColumn==0 && nColumn>0 ){
    keyColumn = pTab->iPKey;
  }

  /* Open the temp table for FOR EACH ROW triggers
  */
  if( pTrigger ){
    sqlite3VdbeAddOp3(v, OP_OpenPseudo, newIdx, 0, pTab->nCol);
  }
    
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows ){
    regRowCount = ++pParse->nMem;

    pParse->nMem++;
  }
  regData = regRowid+1;

  /* Run the BEFORE and INSTEAD OF triggers, if there are any
  */
  endOfLoop = sqlite3VdbeMakeLabel(v);
  if( tmask & TRIGGER_BEFORE ){
    int regTrigRowid;
    int regCols;
    int regRec;

    /* build the NEW.* reference row.  Note that if there is an INTEGER
    ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
    ** translated into a unique ID for the row.  But on a BEFORE trigger,

    }
    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRec, regTrigRowid);
    sqlite3ReleaseTempReg(pParse, regRec);
    sqlite3ReleaseTempReg(pParse, regTrigRowid);
    sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol);

    /* Fire BEFORE or INSTEAD OF triggers */
    if( sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_BEFORE, 
        pTab, newIdx, -1, onError, endOfLoop, 0, 0) ){
      goto insert_cleanup;
    }
  }

  /* Push the record number for the new entry onto the stack.  The
  ** record number is a randomly generate integer created by NewRowid
  ** except when the table has an INTEGER PRIMARY KEY column, in which

      sqlite3CompleteInsertion(
          pParse,
          pTab,
          baseCur,
          regIns,
          aRegIdx,
          0,
          (tmask&TRIGGER_AFTER) ? newIdx : -1,
          appendFlag
       );
    }
  }

  /* Update the count of rows that are inserted
  */
  if( (db->flags & SQLITE_CountRows)!=0 ){
    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
  }

  if( pTrigger ){
    /* Code AFTER triggers */
    if( sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_AFTER, 
          pTab, newIdx, -1, onError, endOfLoop, 0, 0) ){
      goto insert_cleanup;
    }
  }

  /* The bottom of the main insertion loop, if the data source
  ** is a SELECT statement.
  */

  int regAutoinc;                  /* Memory register used by AUTOINC */
  int destHasUniqueIdx = 0;        /* True if pDest has a UNIQUE index */
  int regData, regRowid;           /* Registers holding data and rowid */

  if( pSelect==0 ){
    return 0;   /* Must be of the form  INSERT INTO ... SELECT ... */
  }
  if( sqlite3TriggerList(pParse, pDest) ){
    return 0;   /* tab1 must not have triggers */
  }
#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( pDest->tabFlags & TF_Virtual ){
    return 0;   /* tab1 must not be a virtual table */
  }
#endif

/*
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.839 2009/02/28 10:47:42 danielk1977 Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if we're using the
** autoconf-based build

  Column *aCol;        /* Information about each column */
  Index *pIndex;       /* List of SQL indexes on this table. */
  int tnum;            /* Root BTree node for this table (see note above) */
  Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
  u16 nRef;            /* Number of pointers to this Table */
  u8 tabFlags;         /* Mask of TF_* values */
  u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */

  FKey *pFKey;         /* Linked list of all foreign keys in this table */
  char *zColAff;       /* String defining the affinity of each column */
#ifndef SQLITE_OMIT_CHECK
  Expr *pCheck;        /* The AND of all CHECK constraints */
#endif
#ifndef SQLITE_OMIT_ALTERTABLE
  int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
  Module *pMod;        /* Pointer to the implementation of the module */
  sqlite3_vtab *pVtab; /* Pointer to the module instance */
  int nModuleArg;      /* Number of arguments to the module */
  char **azModuleArg;  /* Text of all module args. [0] is module name */
#endif
  Trigger *pTrigger;   /* List of triggers stored in pSchema */
  Schema *pSchema;     /* Schema that contains this table */
  Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
};

/*
** Allowed values for Tabe.tabFlags.
*/

#ifndef SQLITE_OMIT_TRIGGER
  void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
                           Expr*,int, int);
  void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
  void sqlite3DropTrigger(Parse*, SrcList*, int);
  void sqlite3DropTriggerPtr(Parse*, Trigger*);
  Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
  Trigger *sqlite3TriggerList(Parse *, Table *);
  int sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
                            int, int, int, int, u32*, u32*);
  void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
  void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
  TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
  TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
                                        ExprList*,Select*,int);
  TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, int);
  TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
  void sqlite3DeleteTrigger(sqlite3*, Trigger*);
  void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
#else
# define sqlite3TriggersExist(B,C,D,E,F) 0
# define sqlite3DeleteTrigger(A,B)
# define sqlite3DropTriggerPtr(A,B)
# define sqlite3UnlinkAndDeleteTrigger(A,B,C)
# define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I,J,K,L) 0
#endif

int sqlite3JoinType(Parse*, Token*, Token*, Token*);
void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
void sqlite3DeferForeignKey(Parse*, int);
#ifndef SQLITE_OMIT_AUTHORIZATION
  void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);

/*
**
** 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.
**
*************************************************************************
**
**
** $Id: trigger.c,v 1.135 2009/02/28 10:47:42 danielk1977 Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_TRIGGER
/*
** Delete a linked list of TriggerStep structures.
*/

    sqlite3ExprListDelete(db, pTmp->pExprList);
    sqlite3SelectDelete(db, pTmp->pSelect);
    sqlite3IdListDelete(db, pTmp->pIdList);

    sqlite3DbFree(db, pTmp);
  }
}

/*
** Given table pTab, return a list of all the triggers attached to 
** the table. The list is connected by Trigger.pNext pointers.
*/
Trigger *sqlite3TriggerList(Parse *pParse, Table *pTab){
  Schema * const pTmpSchema = pParse->db->aDb[1].pSchema;
  Trigger *pList = 0;                  /* List of triggers to return */

  if( pTmpSchema!=pTab->pSchema ){
    HashElem *p;
    for(p=sqliteHashFirst(&pTmpSchema->trigHash); p; p=sqliteHashNext(p)){
      Trigger *pTrig = (Trigger *)sqliteHashData(p);
      if( pTrig->pTabSchema==pTab->pSchema
       && 0==sqlite3StrICmp(pTrig->table, pTab->zName) 
      ){
        pTrig->pNext = (pList ? pList : pTab->pTrigger);
        pList = pTrig;
      }
    }
  }

  return (pList ? pList : pTab->pTrigger);
}

/*
** This is called by the parser when it sees a CREATE TRIGGER statement
** up to the point of the BEGIN before the trigger actions.  A Trigger
** structure is generated based on the information available and stored
** in pParse->pNewTrigger.  After the trigger actions have been parsed, the
** sqlite3FinishTrigger() function is called to complete the trigger

** in order to complete the process of building the trigger.
*/
void sqlite3FinishTrigger(
  Parse *pParse,          /* Parser context */
  TriggerStep *pStepList, /* The triggered program */
  Token *pAll             /* Token that describes the complete CREATE TRIGGER */
){
  Trigger *pTrig = pParse->pNewTrigger;    /* Trigger being finished */
  char *zName;                             /* Name of trigger */
  sqlite3 *db = pParse->db;                /* The database */
  DbFixer sFix;
  int iDb;                                 /* Database containing the trigger */

  pTrig = pParse->pNewTrigger;
  pParse->pNewTrigger = 0;
  if( pParse->nErr || !pTrig ) goto triggerfinish_cleanup;
  zName = pTrig->name;
  iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
  pTrig->step_list = pStepList;
  while( pStepList ){
    pStepList->pTrig = pTrig;
    pStepList = pStepList->pNext;
  }
  if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", &pTrig->nameToken) 

    /* Make an entry in the sqlite_master table */
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto triggerfinish_cleanup;
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    z = sqlite3DbStrNDup(db, (char*)pAll->z, pAll->n);
    sqlite3NestedParse(pParse,
       "INSERT INTO %Q.%s VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')",
       db->aDb[iDb].zName, SCHEMA_TABLE(iDb), zName,
       pTrig->table, z);
    sqlite3DbFree(db, z);
    sqlite3ChangeCookie(pParse, iDb);
    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0, sqlite3MPrintf(
        db, "type='trigger' AND name='%q'", zName), P4_DYNAMIC
    );
  }

  if( db->init.busy ){


    Trigger *pLink = pTrig;
    Hash *pHash = &db->aDb[iDb].pSchema->trigHash;
    pTrig = sqlite3HashInsert(pHash, zName, sqlite3Strlen30(zName), pTrig);
    if( pTrig ){

      db->mallocFailed = 1;
    }else if( pLink->pSchema==pLink->pTabSchema ){
      Table *pTab;

      int n = sqlite3Strlen30(pLink->table) + 1;
      pTab = sqlite3HashFind(&pLink->pTabSchema->tblHash, pLink->table, n);
      assert( pTab!=0 );
      pLink->pNext = pTab->pTrigger;
      pTab->pTrigger = pLink;

    }
  }

triggerfinish_cleanup:
  sqlite3DeleteTrigger(db, pTrig);
  assert( !pParse->pNewTrigger );
  sqlite3DeleteTriggerStep(db, pStepList);
}

  }
}

/*
** Remove a trigger from the hash tables of the sqlite* pointer.
*/
void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){
  Hash *pHash = &(db->aDb[iDb].pSchema->trigHash);
  Trigger *pTrigger;

  pTrigger = sqlite3HashInsert(pHash, zName, sqlite3Strlen30(zName), 0);

  if( pTrigger ){
    if( pTrigger->pSchema==pTrigger->pTabSchema ){
      Table *pTab = tableOfTrigger(pTrigger);




      Trigger **pp;

      for(pp=&pTab->pTrigger; *pp!=pTrigger; pp=&((*pp)->pNext));



      *pp = (*pp)->pNext;


    }
    sqlite3DeleteTrigger(db, pTrigger);
    db->flags |= SQLITE_InternChanges;
  }
}

/*

  for(e=0; e<pEList->nExpr; e++){
    if( sqlite3IdListIndex(pIdList, pEList->a[e].zName)>=0 ) return 1;
  }
  return 0; 
}

/*
** Return a list of all triggers on table pTab if there exists at least
** one trigger that must be fired when an operation of type 'op' is 
** performed on the table, and, if that operation is an UPDATE, if at
** least one of the columns in pChanges is being modified.



*/
Trigger *sqlite3TriggersExist(
  Parse *pParse,          /* Parse context */
  Table *pTab,            /* The table the contains the triggers */
  int op,                 /* one of TK_DELETE, TK_INSERT, TK_UPDATE */
  ExprList *pChanges,     /* Columns that change in an UPDATE statement */
  int *pMask              /* OUT: Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
){

  int mask = 0;
  Trigger *pList = sqlite3TriggerList(pParse, pTab);

  Trigger *p;
  assert( pList==0 || IsVirtual(pTab)==0 );
  for(p=pList; p; p=p->pNext){
    if( p->op==op && checkColumnOverLap(p->pColumns, pChanges) ){
      mask |= p->tr_tm;
    }
  }
  if( pMask ){
    *pMask = mask;
  }
  return (mask ? pList : 0);
}

/*
** Convert the pStep->target token into a SrcList and return a pointer
** to that SrcList.
**
** This routine adds a specific database name, if needed, to the target when

** pseudo-table is read at least once, the corresponding bit of the output
** mask is set. If a column with an index greater than 32 is read, the
** output mask is set to the special value 0xffffffff.
**
*/
int sqlite3CodeRowTrigger(
  Parse *pParse,       /* Parse context */
  Trigger *pTrigger,   /* List of triggers on table pTab */
  int op,              /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
  ExprList *pChanges,  /* Changes list for any UPDATE OF triggers */
  int tr_tm,           /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
  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 */

  trigStackEntry.newColMask = 0;

  assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE);
  assert(tr_tm == TRIGGER_BEFORE || tr_tm == TRIGGER_AFTER );

  assert(newIdx != -1 || oldIdx != -1);

  for(p=pTrigger; p; p=p->pNext){
    int fire_this = 0;

    /* Determine whether we should code this trigger */
    if( 
      p->op==op && 
      p->tr_tm==tr_tm && 
      (p->pSchema==p->pTabSchema || p->pSchema==db->aDb[1].pSchema) &&

**    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.
**
** $Id: update.c,v 1.196 2009/02/28 10:47:42 danielk1977 Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */

  NameContext sNC;       /* The name-context to resolve expressions in */
  int iDb;               /* Database containing the table being updated */
  int j1;                /* Addresses of jump instructions */
  int okOnePass;         /* True for one-pass algorithm without the FIFO */

#ifndef SQLITE_OMIT_TRIGGER
  int isView;                  /* Trying to update a view */
  Trigger *pTrigger;           /* List of triggers on pTab, if required */
#endif
  int iBeginAfterTrigger = 0;  /* Address of after trigger program */
  int iEndAfterTrigger = 0;    /* Exit of after trigger program */
  int iBeginBeforeTrigger = 0; /* Address of before trigger program */
  int iEndBeforeTrigger = 0;   /* Exit of before trigger program */
  u32 old_col_mask = 0;        /* Mask of OLD.* columns in use */
  u32 new_col_mask = 0;        /* Mask of NEW.* columns in use */

  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, 0);
  isView = pTab->pSelect!=0;
#else
# define pTrigger 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif

  if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){
    goto update_cleanup;
  }
  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto update_cleanup;
  }
  aXRef = sqlite3DbMallocRaw(db, sizeof(int) * pTab->nCol );
  if( aXRef==0 ) goto update_cleanup;
  for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;

  /* If there are FOR EACH ROW triggers, allocate cursors for the
  ** special OLD and NEW tables
  */
  if( pTrigger ){
    newIdx = pParse->nTab++;
    oldIdx = pParse->nTab++;
  }

  /* 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

  */
  if( isView ){
    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
  }

  /* Generate the code for triggers.
  */
  if( pTrigger ){
    int iGoto;

    /* Create pseudo-tables for NEW and OLD
    */
    sqlite3VdbeAddOp3(v, OP_OpenPseudo, oldIdx, 0, pTab->nCol);
    sqlite3VdbeAddOp3(v, OP_OpenPseudo, newIdx, 0, pTab->nCol);

    iGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    addr = sqlite3VdbeMakeLabel(v);
    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
    if( sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, 
          TRIGGER_BEFORE, pTab, newIdx, oldIdx, onError, addr, 
          &old_col_mask, &new_col_mask) ){
      goto update_cleanup;
    }
    iEndBeforeTrigger = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
    if( sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, 
          TRIGGER_AFTER, pTab, newIdx, oldIdx, onError, addr, 
          &old_col_mask, &new_col_mask) ){
      goto update_cleanup;
    }
    iEndAfterTrigger = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, iGoto);
  }

  /* If we are trying to update a view, realize that view into

                       (char*)pKey, P4_KEYINFO_HANDOFF);
        assert( pParse->nTab>iCur+i+1 );
      }
    }
  }
  
  /* Jump back to this point if a trigger encounters an IGNORE constraint. */
  if( pTrigger ){
    sqlite3VdbeResolveLabel(v, addr);
  }

  /* Top of the update loop */
  if( okOnePass ){
    int a1 = sqlite3VdbeAddOp1(v, OP_NotNull, regOldRowid);
    addr = sqlite3VdbeAddOp0(v, OP_Goto);
    sqlite3VdbeJumpHere(v, a1);
  }else{
    addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, 0, regOldRowid);
  }

  if( pTrigger ){
    int regRowid;
    int regRow;
    int regCols;

    /* Make cursor iCur point to the record that is being updated.
    */
    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid);

  if( db->flags & SQLITE_CountRows && !pParse->trigStack){
    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
  }

  /* If there are triggers, close all the cursors after each iteration
  ** through the loop.  The fire the after triggers.
  */
  if( pTrigger ){
    sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger);
    sqlite3VdbeJumpHere(v, iEndAfterTrigger);
  }

  /* Repeat the above with the next record to be updated, until
  ** all record selected by the WHERE clause have been updated.
  */
  sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
  sqlite3VdbeJumpHere(v, addr);

  /* Close all tables */
  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    if( openAll || aRegIdx[i]>0 ){
      sqlite3VdbeAddOp2(v, OP_Close, iCur+i+1, 0);
    }
  }
  sqlite3VdbeAddOp2(v, OP_Close, iCur, 0);
  if( pTrigger ){
    sqlite3VdbeAddOp2(v, OP_Close, newIdx, 0);
    sqlite3VdbeAddOp2(v, OP_Close, oldIdx, 0);
  }

  /*
  ** Return the number of rows that were changed. If this routine is 
  ** generating code because of a call to sqlite3NestedParse(), do not

# 2009 February 27
#
# 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.
#
#***********************************************************************
#
# $Id: temptrigger.test,v 1.1 2009/02/28 10:47:42 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Test cases:
#
#   temptrigger-1.*: Shared cache problem.
#   temptrigger-2.*: A similar shared cache problem.
#   temptrigger-3.*: Attached database problem.
#

#-------------------------------------------------------------------------
# Test case temptrigger-1.* demonstrates a problem with temp triggers
# in shared-cache mode. If process 1 connections to a shared-cache and
# creates a temp trigger, the temp trigger is linked into the shared-cache
# schema. If process 2 reloads the shared-cache schema from disk, then
# it does not recreate the temp trigger belonging to process 1. From the
# point of view of process 1, the temp trigger just disappeared.
# 
#   temptrigger-1.1: In shared cache mode, create a table in the main 
#                    database and add a temp trigger to it.
#
#   temptrigger-1.2: Check that the temp trigger is correctly fired. Check
#                    that the temp trigger is not fired by statements
#                    executed by a second connection connected to the 
#                    same shared cache.
#
#   temptrigger-1.3: Using the second connection to the shared-cache, cause
#                    the shared-cache schema to be reloaded.
#
#   temptrigger-1.4: Check that the temp trigger is still fired correctly.
#
#   temptrigger-1.5: Check that the temp trigger can be dropped without error.
#
db close
set ::enable_shared_cache [sqlite3_enable_shared_cache]
sqlite3_enable_shared_cache 1

sqlite3 db test.db
sqlite3 db2 test.db

do_test temptrigger-1.1 {
  execsql {
    CREATE TABLE t1(a, b);
    CREATE TEMP TABLE tt1(a, b);
    CREATE TEMP TRIGGER tr1 AFTER INSERT ON t1 BEGIN
      INSERT INTO tt1 VALUES(new.a, new.b);
    END;
  }
} {}

do_test temptrigger-1.2.1 {
  execsql { INSERT INTO t1 VALUES(1, 2) }
  execsql { SELECT * FROM t1 }
} {1 2}
do_test temptrigger-1.2.2 {
  execsql { SELECT * FROM tt1 }
} {1 2}
do_test temptrigger-1.2.3 {
  execsql { INSERT INTO t1 VALUES(3, 4) } db2
  execsql { SELECT * FROM t1 }
} {1 2 3 4}
do_test temptrigger-1.2.4 {
  execsql { SELECT * FROM tt1 }
} {1 2}

# Cause the shared-cache schema to be reloaded.
#
do_test temptrigger-1.3 {
  execsql { BEGIN; CREATE TABLE t3(a, b); ROLLBACK; } db2
} {}

do_test temptrigger-1.4 {
  execsql { INSERT INTO t1 VALUES(5, 6) }
  execsql { SELECT * FROM tt1 }
} {1 2 5 6}

do_test temptrigger-1.5 {
  # Before the bug was fixed, the following 'DROP TRIGGER' hit an 
  # assert if executed.
  #execsql { DROP TRIGGER tr1 }
} {}

catch {db close}
catch {db2 close}

#-------------------------------------------------------------------------
# Tests temptrigger-2.* are similar to temptrigger-1.*, except that
# temptrigger-2.3 simply opens and closes a connection to the shared-cache.
# It does not do anything special to cause the schema to be reloaded.
# 
do_test temptrigger-2.1 {
  sqlite3 db test.db
  execsql {
    DELETE FROM t1;
    CREATE TEMP TABLE tt1(a, b);
    CREATE TEMP TRIGGER tr1 AFTER INSERT ON t1 BEGIN
      INSERT INTO tt1 VALUES(new.a, new.b);
    END;
  }
} {}
do_test temptrigger-2.2 {
  execsql {
    INSERT INTO t1 VALUES(10, 20);
    SELECT * FROM tt1;
  }
} {10 20}
do_test temptrigger-2.3 {
  sqlite3 db2 test.db
  db2 close
} {}
do_test temptrigger-2.4 {
  execsql {
    INSERT INTO t1 VALUES(30, 40);
    SELECT * FROM tt1;
  }
} {10 20 30 40}
do_test temptrigger-2.5 {
  #execsql { DROP TRIGGER tr1 }
} {}

catch {db close}
catch {db2 close}
sqlite3_enable_shared_cache $::enable_shared_cache

#-------------------------------------------------------------------------
# Test case temptrigger-3.* demonstrates a problem with temp triggers
# on tables located in attached databases. At one point when SQLite reloaded 
# the schema of an attached database (because some other connection had 
# changed the schema cookie) it was not re-creating temp triggers attached 
# to tables located within the attached database.
# 
#   temptrigger-3.1: Attach database 'test2.db' to connection [db]. Add a
#                    temp trigger to a table in 'test2.db'.
#
#   temptrigger-3.2: Check that the temp trigger is correctly fired.
#
#   temptrigger-3.3: Update the schema of 'test2.db' using an external
#                    connection. This forces [db] to reload the 'test2.db'
#                    schema. Check that the temp trigger is still fired
#                    correctly.
#
#   temptrigger-3.4: Check that the temp trigger can be dropped without error.
# 
do_test temptrigger-3.1 {
  catch { file delete -force test2.db test2.db-journal }
  catch { file delete -force test.db test.db-journal }
  sqlite3 db test.db 
  sqlite3 db2 test2.db 
  execsql { CREATE TABLE t2(a, b) } db2
  execsql {
    ATTACH 'test2.db' AS aux;
    CREATE TEMP TABLE tt2(a, b);
    CREATE TEMP TRIGGER tr2 AFTER INSERT ON aux.t2 BEGIN
      INSERT INTO tt2 VALUES(new.a, new.b);
    END;
  }
} {}

do_test temptrigger-3.2.1 {
  execsql { 
    INSERT INTO aux.t2 VALUES(1, 2);
    SELECT * FROM aux.t2;
  }
} {1 2}
do_test temptrigger-3.2.2 {
  execsql { SELECT * FROM tt2 }
} {1 2}

do_test temptrigger-3.3.1 {
  execsql { CREATE TABLE t3(a, b) } db2
  execsql { 
    INSERT INTO aux.t2 VALUES(3, 4);
    SELECT * FROM aux.t2;
  }
} {1 2 3 4}
do_test temptrigger-3.3.2 {
  execsql { SELECT * FROM tt2 }
} {1 2 3 4}

do_test temptrigger-3.4 {
  # Before the bug was fixed, the following 'DROP TRIGGER' hit an 
  # assert if executed.
  #execsql { DROP TRIGGER tr2 }
} {}

catch { db close }
catch { db2 close }

finish_test