SQLite

/*
** Generate code for a DELETE FROM statement.
**
**     DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
**                 \________/       \________________/
**                  pTabList              pWhere
*/
void sqlite3DeleteFrom(
  Parse *pParse,         /* The parser context */
  SrcList *pTabList,     /* The table from which we should delete things */
  Expr *pWhere,          /* The WHERE clause.  May be null */
  ExprList *pOrderBy,    /* ORDER BY clause. May be null */
  Expr *pLimit,          /* LIMIT clause. May be null */
  Expr *pOffset          /* OFFSET clause. May be null */
){
  Vdbe *v;               /* The virtual database engine */
  Table *pTab;           /* The table from which records will be deleted */
  int i;                 /* Loop counter */
  WhereInfo *pWInfo;     /* Information about the WHERE clause */
  Index *pIdx;           /* For looping over indices of the table */
  int iTabCur;           /* Cursor number for the table */

    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC);
  }

delete_from_cleanup:
  sqlite3AuthContextPop(&sContext);
  sqlite3SrcListDelete(db, pTabList);
  sqlite3ExprDelete(db, pWhere);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) 
  sqlite3ExprListDelete(db, pOrderBy);
  sqlite3ExprDelete(db, pLimit);
  sqlite3ExprDelete(db, pOffset);
#endif
  sqlite3DbFree(db, aToOpen);
  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

      }
      if( !p ) return;
      iSkip = sqlite3VdbeMakeLabel(v);
      sqlite3VdbeAddOp2(v, OP_FkIfZero, 1, iSkip); VdbeCoverage(v);
    }

    pParse->disableTriggers = 1;
    sqlite3DeleteFrom(pParse, sqlite3SrcListDup(db, pName, 0), 0, 0, 0, 0);
    pParse->disableTriggers = 0;

    /* If the DELETE has generated immediate foreign key constraint 
    ** violations, halt the VDBE and return an error at this point, before
    ** any modifications to the schema are made. This is because statement
    ** transactions are not able to rollback schema changes.  
    **

/////////////////////////// The DELETE statement /////////////////////////////
//
%ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) DELETE FROM fullname(X) indexed_opt(I) where_opt(W) 
        orderby_opt(O) limit_opt(L). {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3DeleteFrom(pParse,X,W,O,L.pLimit,L.pOffset); 
}
%endif
%ifndef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) DELETE FROM fullname(X) indexed_opt(I) where_opt(W). {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3DeleteFrom(pParse,X,W,0,0,0);
}
%endif

%type where_opt {Expr*}
%destructor where_opt {sqlite3ExprDelete(pParse->db, $$);}

where_opt(A) ::= .                    {A = 0;}
where_opt(A) ::= WHERE expr(X).       {A = X.pExpr;}

////////////////////////// The UPDATE command ////////////////////////////////
//
%ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) UPDATE orconf(R) fullname(X) indexed_opt(I) SET setlist(Y)
        where_opt(W) orderby_opt(O) limit_opt(L).  {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3ExprListCheckLength(pParse,Y,"set list"); 
  sqlite3Update(pParse,X,Y,W,R,O,L.pLimit,L.pOffset);
}
%endif
%ifndef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) UPDATE orconf(R) fullname(X) indexed_opt(I) SET setlist(Y)
        where_opt(W).  {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3ExprListCheckLength(pParse,Y,"set list"); 
  sqlite3Update(pParse,X,Y,W,R,0,0,0);
}
%endif

%type setlist {ExprList*}
%destructor setlist {sqlite3ExprListDelete(pParse->db, $$);}

setlist(A) ::= setlist(A) COMMA nm(X) EQ expr(Y). {

    ** clause processing on UPDATE and DELETE statements.
    */
    case TK_ROW: {
      SrcList *pSrcList = pNC->pSrcList;
      struct SrcList_item *pItem;
      assert( pSrcList && pSrcList->nSrc==1 );
      pItem = pSrcList->a;
      assert( HasRowid(pItem->pTab) && pItem->pTab->pSelect==0 );



      pExpr->op = TK_COLUMN;
      pExpr->pTab = pItem->pTab;
      pExpr->iTable = pItem->iCursor;
      pExpr->iColumn = -1;
      pExpr->affinity = SQLITE_AFF_INTEGER;
      break;
    }

void sqlite3SelectDelete(sqlite3*, Select*);
Table *sqlite3SrcListLookup(Parse*, SrcList*);
int sqlite3IsReadOnly(Parse*, Table*, int);
void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,Expr*,char*);
#endif
void sqlite3DeleteFrom(Parse*, SrcList*, Expr*, ExprList*, Expr*, Expr*);

void sqlite3Update(Parse*, SrcList*, ExprList*,Expr*,int,ExprList*,Expr*,Expr*);


WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
void sqlite3WhereEnd(WhereInfo*);
LogEst sqlite3WhereOutputRowCount(WhereInfo*);
int sqlite3WhereIsDistinct(WhereInfo*);
int sqlite3WhereIsOrdered(WhereInfo*);
int sqlite3WhereOrderedInnerLoop(WhereInfo*);
int sqlite3WhereIsSorted(WhereInfo*);

    switch( pStep->op ){
      case TK_UPDATE: {
        sqlite3Update(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprListDup(db, pStep->pExprList, 0), 
          sqlite3ExprDup(db, pStep->pWhere, 0), 
          pParse->eOrconf, 0, 0, 0
        );
        break;
      }
      case TK_INSERT: {
        sqlite3Insert(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3SelectDup(db, pStep->pSelect, 0), 
          sqlite3IdListDup(db, pStep->pIdList), 
          pParse->eOrconf
        );
        break;
      }
      case TK_DELETE: {
        sqlite3DeleteFrom(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprDup(db, pStep->pWhere, 0), 0, 0, 0
        );
        break;
      }
      default: assert( pStep->op==TK_SELECT ); {
        SelectDest sDest;
        Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
        sqlite3SelectDestInit(&sDest, SRT_Discard, 0);

/*
** Process an UPDATE statement.
**
**   UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;
**          \_______/ \________/     \______/       \________________/
*            onError   pTabList      pChanges             pWhere
*/
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 */
  Expr *pOffset          /* OFFSET clause. May be null */
){
  int i, j;              /* Loop counters */
  Table *pTab;           /* The table to be updated */
  int addrTop = 0;       /* VDBE instruction address of the start of the loop */
  WhereInfo *pWInfo;     /* Information about the WHERE clause */
  Vdbe *v;               /* The virtual database engine */
  Index *pIdx;           /* For looping over indices */

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);
  sqlite3ExprDelete(db, pOffset);
#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