SQLite

    /* Disable lookaside memory allocation */
    enableLookaside = db->lookaside.bEnabled;
    db->lookaside.bEnabled = 0;

    pTrigger = (Trigger *)sqlite3DbMallocZero(db, 
        sizeof(Trigger) +         /* struct Trigger */
        sizeof(TriggerStep) +     /* Single step in trigger program */
        nFrom + 1                 /* Space for pStep->zTarget */
    );
    if( pTrigger ){
      pStep = pTrigger->step_list = (TriggerStep *)&pTrigger[1];
      pStep->zTarget = (char *)&pStep[1];

      memcpy((char *)pStep->zTarget, zFrom, nFrom);
  
      pStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
      pStep->pExprList = sqlite3ExprListDup(db, pList, EXPRDUP_REDUCE);
      pStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
      if( pWhen ){
        pWhen = sqlite3PExpr(pParse, TK_NOT, pWhen, 0, 0);
        pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);

 * "SELECT" statement. The meanings of the other members is determined by the 
 * value of "op" as follows:
 *
 * (op == TK_INSERT)
 * orconf    -> stores the ON CONFLICT algorithm
 * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
 *              this stores a pointer to the SELECT statement. Otherwise NULL.
 * zTarget   -> Dequoted name of the table to insert into.
 * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
 *              this stores values to be inserted. Otherwise NULL.
 * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ... 
 *              statement, then this stores the column-names to be
 *              inserted into.
 *
 * (op == TK_DELETE)
 * zTarget   -> Dequoted name of the table to delete from.
 * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
 *              Otherwise NULL.
 * 
 * (op == TK_UPDATE)
 * zTarget   -> Dequoted name of the table to update.
 * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
 *              Otherwise NULL.
 * pExprList -> A list of the columns to update and the expressions to update
 *              them to. See sqlite3Update() documentation of "pChanges"
 *              argument.
 * 
 */
struct TriggerStep {
  u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
  u8 orconf;           /* OE_Rollback etc. */
  Trigger *pTrig;      /* The trigger that this step is a part of */
  Select *pSelect;     /* SELECT statement or RHS of INSERT INTO SELECT ... */
  char *zTarget;       /* Target table for DELETE, UPDATE, INSERT */
  Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
  ExprList *pExprList; /* SET clause for UPDATE. */
  IdList *pIdList;     /* Column names for INSERT */
  TriggerStep *pNext;  /* Next in the link-list */
  TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
};

static TriggerStep *triggerStepAllocate(
  sqlite3 *db,                /* Database connection */
  u8 op,                      /* Trigger opcode */
  Token *pName                /* The target name */
){
  TriggerStep *pTriggerStep;

  pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep) + pName->n + 1);
  if( pTriggerStep ){
    char *z = (char*)&pTriggerStep[1];
    memcpy(z, pName->z, pName->n);
    sqlite3Dequote(z);
    pTriggerStep->zTarget = z;

    pTriggerStep->op = op;
  }
  return pTriggerStep;
}

/*
** Build a trigger step out of an INSERT statement.  Return a pointer

  if( pMask ){
    *pMask = mask;
  }
  return (mask ? pList : 0);
}

/*
** Convert the pStep->zTarget string into a SrcList and return a pointer
** to that SrcList.
**
** This routine adds a specific database name, if needed, to the target when
** forming the SrcList.  This prevents a trigger in one database from
** referring to a target in another database.  An exception is when the
** trigger is in TEMP in which case it can refer to any other database it
** wants.
*/
static SrcList *targetSrcList(
  Parse *pParse,       /* The parsing context */
  TriggerStep *pStep   /* The trigger containing the target token */
){
  sqlite3 *db = pParse->db;
  int iDb;             /* Index of the database to use */
  SrcList *pSrc;       /* SrcList to be returned */

  pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
  if( pSrc ){
    assert( pSrc->nSrc>0 );
    pSrc->a[pSrc->nSrc-1].zName = sqlite3DbStrDup(db, pStep->zTarget);

    iDb = sqlite3SchemaToIndex(db, pStep->pTrig->pSchema);
    if( iDb==0 || iDb>=2 ){

      assert( iDb<db->nDb );
      pSrc->a[pSrc->nSrc-1].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zName);
    }
  }
  return pSrc;
}

/*

#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix triggerC
ifcapable {!trigger} {
  finish_test
  return
}

#-------------------------------------------------------------------------
# Test organization:

}

reset_db
do_execsql_test triggerC-14.1 $SQL {1 2 3}
reset_db
optimization_control db factor-constants 0
do_execsql_test triggerC-14.2 $SQL {1 2 3}

#-------------------------------------------------------------------------
# Check that table names used by trigger programs are dequoted exactly
# once.
#
do_execsql_test 15.1.1 {
  PRAGMA recursive_triggers = 1;
  CREATE TABLE node(
      id int not null primary key, 
      pid int not null default 0 references node,
      key varchar not null, 
      path varchar default '',
      unique(pid, key)
      );
  CREATE TRIGGER node_delete_referencing AFTER DELETE ON "node"
    BEGIN
    DELETE FROM "node" WHERE pid = old."id";
  END;
}
do_execsql_test 15.1.2 {
  INSERT INTO node(id, pid, key) VALUES(9, 0, 'test');
  INSERT INTO node(id, pid, key) VALUES(90, 9, 'test1');
  INSERT INTO node(id, pid, key) VALUES(900, 90, 'test2');
  DELETE FROM node WHERE id=9;
  SELECT * FROM node;
}

do_execsql_test 15.2.1 {
  CREATE TABLE   x1  (x);

  CREATE TABLE   x2  (a, b);
  CREATE TABLE '"x2"'(a, b);

  INSERT INTO x2 VALUES(1, 2);
  INSERT INTO x2 VALUES(3, 4);
  INSERT INTO '"x2"' SELECT * FROM x2;

  CREATE TRIGGER x1ai AFTER INSERT ON x1 BEGIN
    INSERT INTO """x2""" VALUES('x', 'y');
    DELETE FROM """x2""" WHERE a=1;
    UPDATE """x2""" SET b = 11 WHERE a = 3;
  END;

  INSERT INTO x1 VALUES('go!');
}

do_execsql_test 15.2.2 { SELECT * FROM x2;       } {1 2 3 4}
do_execsql_test 15.2.3 { SELECT * FROM """x2"""; } {3 11 x y}

finish_test