src/upsert.c

   1 /*
   2 ** 2018-04-12
   3 **
   4 ** The author disclaims copyright to this source code.  In place of
   5 ** a legal notice, here is a blessing:
   6 **
   7 **    May you do good and not evil.
   8 **    May you find forgiveness for yourself and forgive others.
   9 **    May you share freely, never taking more than you give.
  10 **
  11 *************************************************************************
  12 ** This file contains code to implement various aspects of UPSERT
  13 ** processing and handling of the Upsert object.
  14 */
  15 #include "sqliteInt.h"
  16
  17 #ifndef SQLITE_OMIT_UPSERT
  18 /*
  19 ** Free a list of Upsert objects
  20 */
  21 void sqlite3UpsertDelete(sqlite3 *db, Upsert *p){
  22   while( p ){
  23     Upsert *pNext = p->pUpsertNext;
  24     sqlite3ExprListDelete(db, p->pUpsertTarget);
  25     sqlite3ExprListDelete(db, p->pUpsertSet);
  26     sqlite3ExprDelete(db, p->pUpsertWhere);
  27     sqlite3DbFree(db, p);
  28     p = pNext;
  29   }
  30 }
  31
  32 /*
  33 ** Duplicate an Upsert object.
  34 */
  35 Upsert *sqlite3UpsertDup(sqlite3 *db, Upsert *p){
  36   if( p==0 ) return 0;
  37   return sqlite3UpsertNew(db,
  38            sqlite3UpsertDup(db, p->pUpsertNext),
  39            sqlite3ExprListDup(db, p->pUpsertTarget, 0),
  40            sqlite3ExprListDup(db, p->pUpsertSet, 0),
  41            sqlite3ExprDup(db, p->pUpsertWhere, 0)
  42          );
  43 }
  44
  45 /*
  46 ** Create a new Upsert object.
  47 */
  48 Upsert *sqlite3UpsertNew(
  49   sqlite3 *db,           /* Determines which memory allocator to use */
  50   Upsert *pPrior,        /* Append this upsert to the end of the new one */
  51   ExprList *pTarget,     /* Target argument to ON CONFLICT, or NULL */
  52   ExprList *pSet,        /* UPDATE columns, or NULL for a DO NOTHING */
  53   Expr *pWhere           /* WHERE clause for the ON CONFLICT UPDATE */
  54 ){
  55   Upsert *pNew;
  56   pNew = sqlite3DbMallocRaw(db, sizeof(Upsert));
  57   if( pNew==0 ){
  58     sqlite3UpsertDelete(db, pPrior);
  59     sqlite3ExprListDelete(db, pTarget);
  60     sqlite3ExprListDelete(db, pSet);
  61     sqlite3ExprDelete(db, pWhere);
  62     return 0;
  63   }else{
  64     pNew->pUpsertTarget = pTarget;
  65     pNew->pUpsertSet = pSet;
  66     pNew->pUpsertNext = pPrior;
  67     pNew->pUpsertWhere = pWhere;
  68   }
  69   return pNew;
  70 }
  71
  72 #endif /* SQLITE_OMIT_UPSERT */