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 static void SQLITE_NOINLINE upsertDelete(sqlite3 *db, Upsert *p){
  22   do{
  23     Upsert *pNext = p->pNextUpsert;
  24     sqlite3ExprListDelete(db, p->pUpsertTarget);
  25     sqlite3ExprDelete(db, p->pUpsertTargetWhere);
  26     sqlite3ExprListDelete(db, p->pUpsertSet);
  27     sqlite3ExprDelete(db, p->pUpsertWhere);
  28     sqlite3DbFree(db, p->pToFree);
  29     sqlite3DbFree(db, p);
  30     p = pNext;
  31   }while( p );
  32 }
  33 void sqlite3UpsertDelete(sqlite3 *db, Upsert *p){
  34   if( p ) upsertDelete(db, p);
  35 }
  36
  37
  38 /*
  39 ** Duplicate an Upsert object.
  40 */
  41 Upsert *sqlite3UpsertDup(sqlite3 *db, Upsert *p){
  42   if( p==0 ) return 0;
  43   return sqlite3UpsertNew(db,
  44            sqlite3ExprListDup(db, p->pUpsertTarget, 0),
  45            sqlite3ExprDup(db, p->pUpsertTargetWhere, 0),
  46            sqlite3ExprListDup(db, p->pUpsertSet, 0),
  47            sqlite3ExprDup(db, p->pUpsertWhere, 0),
  48            sqlite3UpsertDup(db, p->pNextUpsert)
  49          );
  50 }
  51
  52 /*
  53 ** Create a new Upsert object.
  54 */
  55 Upsert *sqlite3UpsertNew(
  56   sqlite3 *db,           /* Determines which memory allocator to use */
  57   ExprList *pTarget,     /* Target argument to ON CONFLICT, or NULL */
  58   Expr *pTargetWhere,    /* Optional WHERE clause on the target */
  59   ExprList *pSet,        /* UPDATE columns, or NULL for a DO NOTHING */
  60   Expr *pWhere,          /* WHERE clause for the ON CONFLICT UPDATE */
  61   Upsert *pNext          /* Next ON CONFLICT clause in the list */
  62 ){
  63   Upsert *pNew;
  64   pNew = sqlite3DbMallocZero(db, sizeof(Upsert));
  65   if( pNew==0 ){
  66     sqlite3ExprListDelete(db, pTarget);
  67     sqlite3ExprDelete(db, pTargetWhere);
  68     sqlite3ExprListDelete(db, pSet);
  69     sqlite3ExprDelete(db, pWhere);
  70     sqlite3UpsertDelete(db, pNext);
  71     return 0;
  72   }else{
  73     pNew->pUpsertTarget = pTarget;
  74     pNew->pUpsertTargetWhere = pTargetWhere;
  75     pNew->pUpsertSet = pSet;
  76     pNew->pUpsertWhere = pWhere;
  77     pNew->isDoUpdate = pSet!=0;
  78     pNew->pNextUpsert = pNext;
  79   }
  80   return pNew;
  81 }
  82
  83 /*
  84 ** Analyze the ON CONFLICT clause described by pUpsert.  Resolve all
  85 ** symbols in the conflict-target.
  86 **
  87 ** Return SQLITE_OK if everything works, or an error code is something
  88 ** is wrong.
  89 */
  90 int sqlite3UpsertAnalyzeTarget(
  91   Parse *pParse,     /* The parsing context */
  92   SrcList *pTabList, /* Table into which we are inserting */
  93   Upsert *pUpsert    /* The ON CONFLICT clauses */
  94 ){
  95   Table *pTab;            /* That table into which we are inserting */
  96   int rc;                 /* Result code */
  97   int iCursor;            /* Cursor used by pTab */
  98   Index *pIdx;            /* One of the indexes of pTab */
  99   ExprList *pTarget;      /* The conflict-target clause */
 100   Expr *pTerm;            /* One term of the conflict-target clause */
 101   NameContext sNC;        /* Context for resolving symbolic names */
 102   Expr sCol[2];           /* Index column converted into an Expr */
 103   int nClause = 0;        /* Counter of ON CONFLICT clauses */
 104
 105   assert( pTabList->nSrc==1 );
 106   assert( pTabList->a[0].pTab!=0 );
 107   assert( pUpsert!=0 );
 108   assert( pUpsert->pUpsertTarget!=0 );
 109
 110   /* Resolve all symbolic names in the conflict-target clause, which
 111   ** includes both the list of columns and the optional partial-index
 112   ** WHERE clause.
 113   */
 114   memset(&sNC, 0, sizeof(sNC));
 115   sNC.pParse = pParse;
 116   sNC.pSrcList = pTabList;
 117   for(; pUpsert && pUpsert->pUpsertTarget;
 118         pUpsert=pUpsert->pNextUpsert, nClause++){
 119     rc = sqlite3ResolveExprListNames(&sNC, pUpsert->pUpsertTarget);
 120     if( rc ) return rc;
 121     rc = sqlite3ResolveExprNames(&sNC, pUpsert->pUpsertTargetWhere);
 122     if( rc ) return rc;
 123
 124     /* Check to see if the conflict target matches the rowid. */
 125     pTab = pTabList->a[0].pTab;
 126     pTarget = pUpsert->pUpsertTarget;
 127     iCursor = pTabList->a[0].iCursor;
 128     if( HasRowid(pTab)
 129      && pTarget->nExpr==1
 130      && (pTerm = pTarget->a[0].pExpr)->op==TK_COLUMN
 131      && pTerm->iColumn==XN_ROWID
 132     ){
 133       /* The conflict-target is the rowid of the primary table */
 134       assert( pUpsert->pUpsertIdx==0 );
 135       continue;
 136     }
 137
 138     /* Initialize sCol[0..1] to be an expression parse tree for a
 139     ** single column of an index.  The sCol[0] node will be the TK_COLLATE
 140     ** operator and sCol[1] will be the TK_COLUMN operator.  Code below
 141     ** will populate the specific collation and column number values
 142     ** prior to comparing against the conflict-target expression.
 143     */
 144     memset(sCol, 0, sizeof(sCol));
 145     sCol[0].op = TK_COLLATE;
 146     sCol[0].pLeft = &sCol[1];
 147     sCol[1].op = TK_COLUMN;
 148     sCol[1].iTable = pTabList->a[0].iCursor;
 149
 150     /* Check for matches against other indexes */
 151     for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
 152       int ii, jj, nn;
 153       if( !IsUniqueIndex(pIdx) ) continue;
 154       if( pTarget->nExpr!=pIdx->nKeyCol ) continue;
 155       if( pIdx->pPartIdxWhere ){
 156         if( pUpsert->pUpsertTargetWhere==0 ) continue;
 157         if( sqlite3ExprCompare(pParse, pUpsert->pUpsertTargetWhere,
 158                                pIdx->pPartIdxWhere, iCursor)!=0 ){
 159           continue;
 160         }
 161       }
 162       nn = pIdx->nKeyCol;
 163       for(ii=0; ii<nn; ii++){
 164         Expr *pExpr;
 165         sCol[0].u.zToken = (char*)pIdx->azColl[ii];
 166         if( pIdx->aiColumn[ii]==XN_EXPR ){
 167           assert( pIdx->aColExpr!=0 );
 168           assert( pIdx->aColExpr->nExpr>ii );
 169           assert( pIdx->bHasExpr );
 170           pExpr = pIdx->aColExpr->a[ii].pExpr;
 171           if( pExpr->op!=TK_COLLATE ){
 172             sCol[0].pLeft = pExpr;
 173             pExpr = &sCol[0];
 174           }
 175         }else{
 176           sCol[0].pLeft = &sCol[1];
 177           sCol[1].iColumn = pIdx->aiColumn[ii];
 178           pExpr = &sCol[0];
 179         }
 180         for(jj=0; jj<nn; jj++){
 181           if( sqlite3ExprCompare(0,pTarget->a[jj].pExpr,pExpr,iCursor)<2 ){
 182             break;  /* Column ii of the index matches column jj of target */
 183           }
 184         }
 185         if( jj>=nn ){
 186           /* The target contains no match for column jj of the index */
 187           break;
 188         }
 189       }
 190       if( ii<nn ){
 191         /* Column ii of the index did not match any term of the conflict target.
 192         ** Continue the search with the next index. */
 193         continue;
 194       }
 195       pUpsert->pUpsertIdx = pIdx;
 196       break;
 197     }
 198     if( pUpsert->pUpsertIdx==0 ){
 199       char zWhich[16];
 200       if( nClause==0 && pUpsert->pNextUpsert==0 ){
 201         zWhich[0] = 0;
 202       }else{
 203         sqlite3_snprintf(sizeof(zWhich),zWhich,"%r ", nClause+1);
 204       }
 205       sqlite3ErrorMsg(pParse, "%sON CONFLICT clause does not match any "
 206                               "PRIMARY KEY or UNIQUE constraint", zWhich);
 207       return SQLITE_ERROR;
 208     }
 209   }
 210   return SQLITE_OK;
 211 }
 212
 213 /*
 214 ** Return true if pUpsert is the last ON CONFLICT clause with a
 215 ** conflict target, or if pUpsert is followed by another ON CONFLICT
 216 ** clause that targets the INTEGER PRIMARY KEY.
 217 */
 218 int sqlite3UpsertNextIsIPK(Upsert *pUpsert){
 219   Upsert *pNext;
 220   if( NEVER(pUpsert==0) ) return 0;
 221   pNext = pUpsert->pNextUpsert;
 222   if( pNext==0 ) return 1;
 223   if( pNext->pUpsertTarget==0 ) return 1;
 224   if( pNext->pUpsertIdx==0 ) return 1;
 225   return 0;
 226 }
 227
 228 /*
 229 ** Given the list of ON CONFLICT clauses described by pUpsert, and
 230 ** a particular index pIdx, return a pointer to the particular ON CONFLICT
 231 ** clause that applies to the index.  Or, if the index is not subject to
 232 ** any ON CONFLICT clause, return NULL.
 233 */
 234 Upsert *sqlite3UpsertOfIndex(Upsert *pUpsert, Index *pIdx){
 235   while(
 236       pUpsert
 237    && pUpsert->pUpsertTarget!=0
 238    && pUpsert->pUpsertIdx!=pIdx
 239   ){
 240      pUpsert = pUpsert->pNextUpsert;
 241   }
 242   return pUpsert;
 243 }
 244
 245 /*
 246 ** Generate bytecode that does an UPDATE as part of an upsert.
 247 **
 248 ** If pIdx is NULL, then the UNIQUE constraint that failed was the IPK.
 249 ** In this case parameter iCur is a cursor open on the table b-tree that
 250 ** currently points to the conflicting table row. Otherwise, if pIdx
 251 ** is not NULL, then pIdx is the constraint that failed and iCur is a
 252 ** cursor points to the conflicting row.
 253 */
 254 void sqlite3UpsertDoUpdate(
 255   Parse *pParse,        /* The parsing and code-generating context */
 256   Upsert *pUpsert,      /* The ON CONFLICT clause for the upsert */
 257   Table *pTab,          /* The table being updated */
 258   Index *pIdx,          /* The UNIQUE constraint that failed */
 259   int iCur              /* Cursor for pIdx (or pTab if pIdx==NULL) */
 260 ){
 261   Vdbe *v = pParse->pVdbe;
 262   sqlite3 *db = pParse->db;
 263   SrcList *pSrc;            /* FROM clause for the UPDATE */
 264   int iDataCur;
 265   int i;
 266   Upsert *pTop = pUpsert;
 267
 268   assert( v!=0 );
 269   assert( pUpsert!=0 );
 270   iDataCur = pUpsert->iDataCur;
 271   pUpsert = sqlite3UpsertOfIndex(pTop, pIdx);
 272   VdbeNoopComment((v, "Begin DO UPDATE of UPSERT"));
 273   if( pIdx && iCur!=iDataCur ){
 274     if( HasRowid(pTab) ){
 275       int regRowid = sqlite3GetTempReg(pParse);
 276       sqlite3VdbeAddOp2(v, OP_IdxRowid, iCur, regRowid);
 277       sqlite3VdbeAddOp3(v, OP_SeekRowid, iDataCur, 0, regRowid);
 278       VdbeCoverage(v);
 279       sqlite3ReleaseTempReg(pParse, regRowid);
 280     }else{
 281       Index *pPk = sqlite3PrimaryKeyIndex(pTab);
 282       int nPk = pPk->nKeyCol;
 283       int iPk = pParse->nMem+1;
 284       pParse->nMem += nPk;
 285       for(i=0; i<nPk; i++){
 286         int k;
 287         assert( pPk->aiColumn[i]>=0 );
 288         k = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[i]);
 289         sqlite3VdbeAddOp3(v, OP_Column, iCur, k, iPk+i);
 290         VdbeComment((v, "%s.%s", pIdx->zName,
 291                     pTab->aCol[pPk->aiColumn[i]].zCnName));
 292       }
 293       sqlite3VdbeVerifyAbortable(v, OE_Abort);
 294       i = sqlite3VdbeAddOp4Int(v, OP_Found, iDataCur, 0, iPk, nPk);
 295       VdbeCoverage(v);
 296       sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CORRUPT, OE_Abort, 0,
 297             "corrupt database", P4_STATIC);
 298       sqlite3MayAbort(pParse);
 299       sqlite3VdbeJumpHere(v, i);
 300     }
 301   }
 302   /* pUpsert does not own pTop->pUpsertSrc - the outer INSERT statement does.
 303   ** So we have to make a copy before passing it down into sqlite3Update() */
 304   pSrc = sqlite3SrcListDup(db, pTop->pUpsertSrc, 0);
 305   /* excluded.* columns of type REAL need to be converted to a hard real */
 306   for(i=0; i<pTab->nCol; i++){
 307     if( pTab->aCol[i].affinity==SQLITE_AFF_REAL ){
 308       sqlite3VdbeAddOp1(v, OP_RealAffinity, pTop->regData+i);
 309     }
 310   }
 311   sqlite3Update(pParse, pSrc, sqlite3ExprListDup(db,pUpsert->pUpsertSet,0),
 312       sqlite3ExprDup(db,pUpsert->pUpsertWhere,0), OE_Abort, 0, 0, pUpsert);
 313   VdbeNoopComment((v, "End DO UPDATE of UPSERT"));
 314 }
 315
 316 #endif /* SQLITE_OMIT_UPSERT */