dlls/msi/where.c

   1 /*
   2  * Implementation of the Microsoft Installer (msi.dll)
   3  *
   4  * Copyright 2002 Mike McCormack for CodeWeavers
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include <stdarg.h>
  22
  23 #include "windef.h"
  24 #include "winbase.h"
  25 #include "winerror.h"
  26 #include "wine/debug.h"
  27 #include "msi.h"
  28 #include "msiquery.h"
  29 #include "objbase.h"
  30 #include "objidl.h"
  31 #include "msipriv.h"
  32 #include "winnls.h"
  33
  34 #include "query.h"
  35
  36 WINE_DEFAULT_DEBUG_CHANNEL(msidb);
  37
  38 #define MSI_HASH_TABLE_SIZE 37
  39
  40 typedef struct tagMSIHASHENTRY
  41 {
  42     struct tagMSIHASHENTRY *next;
  43     UINT value;
  44     UINT row;
  45 } MSIHASHENTRY;
  46
  47 /* below is the query interface to a table */
  48
  49 typedef struct tagMSIWHEREVIEW
  50 {
  51     MSIVIEW        view;
  52     MSIDATABASE   *db;
  53     MSIVIEW       *table;
  54     UINT           row_count;
  55     MSIHASHENTRY **reorder;
  56     struct expr   *cond;
  57     UINT           rec_index;
  58 } MSIWHEREVIEW;
  59
  60 static void free_hash_table(MSIHASHENTRY **table)
  61 {
  62     MSIHASHENTRY *new, *old;
  63     int i;
  64
  65     if (!table)
  66         return;
  67
  68     for (i = 0; i < MSI_HASH_TABLE_SIZE; i++)
  69     {
  70         new = table[i];
  71
  72         while (new)
  73         {
  74             old = new;
  75             new = old->next;
  76             msi_free(old);
  77         }
  78
  79         table[i] = NULL;
  80     }
  81
  82     msi_free(table);
  83 }
  84
  85 static UINT find_entry_in_hash(MSIHASHENTRY **table, UINT row, UINT *val)
  86 {
  87     MSIHASHENTRY *entry;
  88
  89     if (!table)
  90         return ERROR_SUCCESS;
  91
  92     if (!(entry = table[row % MSI_HASH_TABLE_SIZE]))
  93     {
  94         WARN("Row not found in hash table!\n");
  95         return ERROR_FUNCTION_FAILED;
  96     }
  97
  98     while (entry && entry->row != row)
  99         entry = entry->next;
 100
 101     if (entry) *val = entry->value;
 102     return ERROR_SUCCESS;
 103 }
 104
 105 static UINT add_entry_to_hash(MSIHASHENTRY **table, UINT row, UINT val)
 106 {
 107     MSIHASHENTRY *new = msi_alloc(sizeof(MSIHASHENTRY));
 108     MSIHASHENTRY *prev;
 109
 110     if (!new)
 111         return ERROR_OUTOFMEMORY;
 112
 113     new->next = NULL;
 114     new->value = val;
 115     new->row = row;
 116
 117     prev = table[row % MSI_HASH_TABLE_SIZE];
 118     if (prev)
 119         new->next = prev;
 120
 121     table[row % MSI_HASH_TABLE_SIZE] = new;
 122
 123     return ERROR_SUCCESS;
 124 }
 125
 126 static UINT WHERE_fetch_int( struct tagMSIVIEW *view, UINT row, UINT col, UINT *val )
 127 {
 128     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
 129     UINT r;
 130
 131     TRACE("%p %d %d %p\n", wv, row, col, val );
 132
 133     if( !wv->table )
 134         return ERROR_FUNCTION_FAILED;
 135
 136     if( row > wv->row_count )
 137         return ERROR_NO_MORE_ITEMS;
 138
 139     r = find_entry_in_hash(wv->reorder, row, &row);
 140     if (r != ERROR_SUCCESS)
 141         return r;
 142
 143     return wv->table->ops->fetch_int( wv->table, row, col, val );
 144 }
 145
 146 static UINT WHERE_fetch_stream( struct tagMSIVIEW *view, UINT row, UINT col, IStream **stm )
 147 {
 148     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
 149     UINT r;
 150
 151     TRACE("%p %d %d %p\n", wv, row, col, stm );
 152
 153     if( !wv->table )
 154         return ERROR_FUNCTION_FAILED;
 155
 156     if( row > wv->row_count )
 157         return ERROR_NO_MORE_ITEMS;
 158
 159     r = find_entry_in_hash(wv->reorder, row, &row);
 160     if (r != ERROR_SUCCESS)
 161         return r;
 162
 163     return wv->table->ops->fetch_stream( wv->table, row, col, stm );
 164 }
 165
 166 static UINT WHERE_get_row( struct tagMSIVIEW *view, UINT row, MSIRECORD **rec )
 167 {
 168     MSIWHEREVIEW *wv = (MSIWHEREVIEW *)view;
 169     UINT r;
 170
 171     TRACE("%p %d %p\n", wv, row, rec );
 172
 173     if (!wv->table)
 174         return ERROR_FUNCTION_FAILED;
 175
 176     if (row > wv->row_count)
 177         return ERROR_NO_MORE_ITEMS;
 178
 179     r = find_entry_in_hash(wv->reorder, row, &row);
 180     if (r != ERROR_SUCCESS)
 181         return r;
 182
 183     return wv->table->ops->get_row(wv->table, row, rec);
 184 }
 185
 186 static UINT WHERE_set_row( struct tagMSIVIEW *view, UINT row, MSIRECORD *rec, UINT mask )
 187 {
 188     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
 189     UINT r;
 190
 191     TRACE("%p %d %p %08x\n", wv, row, rec, mask );
 192
 193     if( !wv->table )
 194          return ERROR_FUNCTION_FAILED;
 195
 196     if( row > wv->row_count )
 197         return ERROR_NO_MORE_ITEMS;
 198
 199     r = find_entry_in_hash(wv->reorder, row, &row);
 200     if (r != ERROR_SUCCESS)
 201         return r;
 202
 203     return wv->table->ops->set_row( wv->table, row, rec, mask );
 204 }
 205
 206 static UINT WHERE_delete_row(struct tagMSIVIEW *view, UINT row)
 207 {
 208     MSIWHEREVIEW *wv = (MSIWHEREVIEW *)view;
 209     UINT r;
 210
 211     TRACE("(%p %d)\n", view, row);
 212
 213     if ( !wv->table )
 214         return ERROR_FUNCTION_FAILED;
 215
 216     if ( row > wv->row_count )
 217         return ERROR_NO_MORE_ITEMS;
 218
 219     r = find_entry_in_hash( wv->reorder, row, &row );
 220     if ( r != ERROR_SUCCESS )
 221         return r;
 222
 223     return wv->table->ops->delete_row( wv->table, row );
 224 }
 225
 226 static INT INT_evaluate_binary( INT lval, UINT op, INT rval )
 227 {
 228     switch( op )
 229     {
 230     case OP_EQ:
 231         return ( lval == rval );
 232     case OP_AND:
 233         return ( lval && rval );
 234     case OP_OR:
 235         return ( lval || rval );
 236     case OP_GT:
 237         return ( lval > rval );
 238     case OP_LT:
 239         return ( lval < rval );
 240     case OP_LE:
 241         return ( lval <= rval );
 242     case OP_GE:
 243         return ( lval >= rval );
 244     case OP_NE:
 245         return ( lval != rval );
 246     default:
 247         ERR("Unknown operator %d\n", op );
 248     }
 249     return 0;
 250 }
 251
 252 static INT INT_evaluate_unary( INT lval, UINT op )
 253 {
 254     switch( op )
 255     {
 256     case OP_ISNULL:
 257         return ( !lval );
 258     case OP_NOTNULL:
 259         return ( lval );
 260     default:
 261         ERR("Unknown operator %d\n", op );
 262     }
 263     return 0;
 264 }
 265
 266 static const WCHAR *STRING_evaluate( MSIWHEREVIEW *wv, UINT row,
 267                                      const struct expr *expr,
 268                                      const MSIRECORD *record )
 269 {
 270     UINT val = 0, r;
 271
 272     switch( expr->type )
 273     {
 274     case EXPR_COL_NUMBER_STRING:
 275         r = wv->table->ops->fetch_int( wv->table, row, expr->u.col_number, &val );
 276         if( r != ERROR_SUCCESS )
 277             return NULL;
 278         return msi_string_lookup_id( wv->db->strings, val );
 279
 280     case EXPR_SVAL:
 281         return expr->u.sval;
 282
 283     case EXPR_WILDCARD:
 284         return MSI_RecordGetString( record, ++wv->rec_index );
 285
 286     default:
 287         ERR("Invalid expression type\n");
 288         break;
 289     }
 290     return NULL;
 291 }
 292
 293 static UINT STRCMP_Evaluate( MSIWHEREVIEW *wv, UINT row, const struct expr *cond,
 294                              INT *val, const MSIRECORD *record )
 295 {
 296     int sr;
 297     const WCHAR *l_str, *r_str;
 298
 299     l_str = STRING_evaluate( wv, row, cond->u.expr.left, record );
 300     r_str = STRING_evaluate( wv, row, cond->u.expr.right, record );
 301     if( l_str == r_str ||
 302         ((!l_str || !*l_str) && (!r_str || !*r_str)) )
 303         sr = 0;
 304     else if( l_str && ! r_str )
 305         sr = 1;
 306     else if( r_str && ! l_str )
 307         sr = -1;
 308     else
 309         sr = lstrcmpW( l_str, r_str );
 310
 311     *val = ( cond->u.expr.op == OP_EQ && ( sr == 0 ) ) ||
 312            ( cond->u.expr.op == OP_NE && ( sr != 0 ) );
 313
 314     return ERROR_SUCCESS;
 315 }
 316
 317 static UINT WHERE_evaluate( MSIWHEREVIEW *wv, UINT row,
 318                             struct expr *cond, INT *val, MSIRECORD *record )
 319 {
 320     UINT r, tval;
 321     INT lval, rval;
 322
 323     if( !cond )
 324         return ERROR_SUCCESS;
 325
 326     switch( cond->type )
 327     {
 328     case EXPR_COL_NUMBER:
 329         r = wv->table->ops->fetch_int( wv->table, row, cond->u.col_number, &tval );
 330         *val = tval - 0x8000;
 331         return ERROR_SUCCESS;
 332
 333     case EXPR_COL_NUMBER32:
 334         r = wv->table->ops->fetch_int( wv->table, row, cond->u.col_number, &tval );
 335         *val = tval - 0x80000000;
 336         return r;
 337
 338     case EXPR_UVAL:
 339         *val = cond->u.uval;
 340         return ERROR_SUCCESS;
 341
 342     case EXPR_COMPLEX:
 343         r = WHERE_evaluate( wv, row, cond->u.expr.left, &lval, record );
 344         if( r != ERROR_SUCCESS )
 345             return r;
 346         r = WHERE_evaluate( wv, row, cond->u.expr.right, &rval, record );
 347         if( r != ERROR_SUCCESS )
 348             return r;
 349         *val = INT_evaluate_binary( lval, cond->u.expr.op, rval );
 350         return ERROR_SUCCESS;
 351
 352     case EXPR_UNARY:
 353         r = wv->table->ops->fetch_int( wv->table, row, cond->u.expr.left->u.col_number, &tval );
 354         if( r != ERROR_SUCCESS )
 355             return r;
 356         *val = INT_evaluate_unary( tval, cond->u.expr.op );
 357         return ERROR_SUCCESS;
 358
 359     case EXPR_STRCMP:
 360         return STRCMP_Evaluate( wv, row, cond, val, record );
 361
 362     case EXPR_WILDCARD:
 363         *val = MSI_RecordGetInteger( record, ++wv->rec_index );
 364         return ERROR_SUCCESS;
 365
 366     default:
 367         ERR("Invalid expression type\n");
 368         break;
 369     }
 370
 371     return ERROR_SUCCESS;
 372 }
 373
 374 static UINT WHERE_execute( struct tagMSIVIEW *view, MSIRECORD *record )
 375 {
 376     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
 377     UINT count = 0, r, i;
 378     INT val;
 379     MSIVIEW *table = wv->table;
 380
 381     TRACE("%p %p\n", wv, record);
 382
 383     if( !table )
 384          return ERROR_FUNCTION_FAILED;
 385
 386     r = table->ops->execute( table, record );
 387     if( r != ERROR_SUCCESS )
 388         return r;
 389
 390     r = table->ops->get_dimensions( table, &count, NULL );
 391     if( r != ERROR_SUCCESS )
 392         return r;
 393
 394     free_hash_table(wv->reorder);
 395     wv->reorder = msi_alloc_zero(MSI_HASH_TABLE_SIZE * sizeof(MSIHASHENTRY *));
 396     if( !wv->reorder )
 397         return ERROR_OUTOFMEMORY;
 398
 399     wv->row_count = 0;
 400
 401 if (0) /* disable optimization, there's no guarantee that strings are in the string table */
 402 {
 403     if (wv->cond->type == EXPR_STRCMP)
 404     {
 405         MSIITERHANDLE handle = NULL;
 406         UINT row, value, col;
 407         struct expr *col_cond = wv->cond->u.expr.left;
 408         struct expr *val_cond = wv->cond->u.expr.right;
 409
 410         /* swap conditionals */
 411         if (col_cond->type != EXPR_COL_NUMBER_STRING)
 412         {
 413             val_cond = wv->cond->u.expr.left;
 414             col_cond = wv->cond->u.expr.right;
 415         }
 416
 417         if ((col_cond->type == EXPR_COL_NUMBER_STRING) && (val_cond->type == EXPR_SVAL))
 418         {
 419             col = col_cond->u.col_number;
 420             /* special case for "" - translate it into nil */
 421             if (!val_cond->u.sval[0])
 422                 value = 0;
 423             else
 424             {
 425                 r = msi_string2idW(wv->db->strings, val_cond->u.sval, &value);
 426                 if (r != ERROR_SUCCESS)
 427                 {
 428                     TRACE("no id for %s, assuming it doesn't exist in the table\n", debugstr_w(wv->cond->u.expr.right->u.sval));
 429                     return ERROR_SUCCESS;
 430                 }
 431             }
 432
 433             do
 434             {
 435                 r = table->ops->find_matching_rows(table, col, value, &row, &handle);
 436                 if (r == ERROR_SUCCESS)
 437                     add_entry_to_hash(wv->reorder, wv->row_count++, row);
 438             } while (r == ERROR_SUCCESS);
 439
 440             if (r == ERROR_NO_MORE_ITEMS)
 441                 return ERROR_SUCCESS;
 442             else
 443                 return r;
 444         }
 445         /* else fallback to slow case */
 446     }
 447 }
 448
 449     for( i=0; i<count; i++ )
 450     {
 451         val = 0;
 452         wv->rec_index = 0;
 453         r = WHERE_evaluate( wv, i, wv->cond, &val, record );
 454         if( r != ERROR_SUCCESS )
 455             return r;
 456         if( val )
 457             add_entry_to_hash( wv->reorder, wv->row_count++, i );
 458     }
 459
 460     return ERROR_SUCCESS;
 461 }
 462
 463 static UINT WHERE_close( struct tagMSIVIEW *view )
 464 {
 465     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
 466
 467     TRACE("%p\n", wv );
 468
 469     if( !wv->table )
 470         return ERROR_FUNCTION_FAILED;
 471
 472     return wv->table->ops->close( wv->table );
 473 }
 474
 475 static UINT WHERE_get_dimensions( struct tagMSIVIEW *view, UINT *rows, UINT *cols )
 476 {
 477     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
 478
 479     TRACE("%p %p %p\n", wv, rows, cols );
 480
 481     if( !wv->table )
 482          return ERROR_FUNCTION_FAILED;
 483
 484     if( rows )
 485     {
 486         if( !wv->reorder )
 487             return ERROR_FUNCTION_FAILED;
 488         *rows = wv->row_count;
 489     }
 490
 491     return wv->table->ops->get_dimensions( wv->table, NULL, cols );
 492 }
 493
 494 static UINT WHERE_get_column_info( struct tagMSIVIEW *view,
 495                 UINT n, LPWSTR *name, UINT *type, BOOL *temporary,
 496                 LPWSTR *table_name)
 497 {
 498     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
 499
 500     TRACE("%p %d %p %p %p %p\n", wv, n, name, type, temporary, table_name );
 501
 502     if( !wv->table )
 503          return ERROR_FUNCTION_FAILED;
 504
 505     return wv->table->ops->get_column_info( wv->table, n, name,
 506                                             type, temporary, table_name );
 507 }
 508
 509 static UINT WHERE_modify( struct tagMSIVIEW *view, MSIMODIFY eModifyMode,
 510                           MSIRECORD *rec, UINT row )
 511 {
 512     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
 513
 514     TRACE("%p %d %p\n", wv, eModifyMode, rec);
 515
 516     find_entry_in_hash(wv->reorder, row - 1, &row);
 517     row++;
 518
 519     return wv->table->ops->modify( wv->table, eModifyMode, rec, row );
 520 }
 521
 522 static UINT WHERE_delete( struct tagMSIVIEW *view )
 523 {
 524     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
 525
 526     TRACE("%p\n", wv );
 527
 528     if( wv->table )
 529         wv->table->ops->delete( wv->table );
 530     wv->table = 0;
 531
 532     free_hash_table(wv->reorder);
 533     wv->reorder = NULL;
 534     wv->row_count = 0;
 535
 536     msiobj_release( &wv->db->hdr );
 537     msi_free( wv );
 538
 539     return ERROR_SUCCESS;
 540 }
 541
 542 static UINT WHERE_find_matching_rows( struct tagMSIVIEW *view, UINT col,
 543     UINT val, UINT *row, MSIITERHANDLE *handle )
 544 {
 545     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
 546     UINT r;
 547
 548     TRACE("%p, %d, %u, %p\n", view, col, val, *handle);
 549
 550     if( !wv->table )
 551          return ERROR_FUNCTION_FAILED;
 552
 553     r = wv->table->ops->find_matching_rows( wv->table, col, val, row, handle );
 554     if (r != ERROR_SUCCESS)
 555         return r;
 556
 557     if( *row > wv->row_count )
 558         return ERROR_NO_MORE_ITEMS;
 559
 560     return find_entry_in_hash(wv->reorder, *row, row);
 561 }
 562
 563 static UINT WHERE_sort(struct tagMSIVIEW *view, column_info *columns)
 564 {
 565     MSIWHEREVIEW *wv = (MSIWHEREVIEW *)view;
 566
 567     TRACE("%p %p\n", view, columns);
 568
 569     return wv->table->ops->sort(wv->table, columns);
 570 }
 571
 572 static const MSIVIEWOPS where_ops =
 573 {
 574     WHERE_fetch_int,
 575     WHERE_fetch_stream,
 576     WHERE_get_row,
 577     WHERE_set_row,
 578     NULL,
 579     WHERE_delete_row,
 580     WHERE_execute,
 581     WHERE_close,
 582     WHERE_get_dimensions,
 583     WHERE_get_column_info,
 584     WHERE_modify,
 585     WHERE_delete,
 586     WHERE_find_matching_rows,
 587     NULL,
 588     NULL,
 589     NULL,
 590     NULL,
 591     WHERE_sort,
 592     NULL,
 593 };
 594
 595 static UINT WHERE_VerifyCondition( MSIDATABASE *db, MSIVIEW *table, struct expr *cond,
 596                                    UINT *valid )
 597 {
 598     UINT r, val = 0;
 599
 600     switch( cond->type )
 601     {
 602     case EXPR_COLUMN:
 603         r = VIEW_find_column( table, cond->u.column.column,
 604                               cond->u.column.table, &val );
 605         if( r == ERROR_SUCCESS )
 606         {
 607             UINT type = 0;
 608             r = table->ops->get_column_info( table, val, NULL, &type,
 609                                              NULL, NULL );
 610             if( r == ERROR_SUCCESS )
 611             {
 612                 if (type&MSITYPE_STRING)
 613                     cond->type = EXPR_COL_NUMBER_STRING;
 614                 else if ((type&0xff) == 4)
 615                     cond->type = EXPR_COL_NUMBER32;
 616                 else
 617                     cond->type = EXPR_COL_NUMBER;
 618                 cond->u.col_number = val;
 619                 *valid = 1;
 620             }
 621             else
 622                 *valid = 0;
 623         }
 624         else
 625         {
 626             *valid = 0;
 627             WARN("Couldn't find column %s.%s\n", debugstr_w( cond->u.column.table ), debugstr_w( cond->u.column.column ) );
 628         }
 629         break;
 630     case EXPR_COMPLEX:
 631         r = WHERE_VerifyCondition( db, table, cond->u.expr.left, valid );
 632         if( r != ERROR_SUCCESS )
 633             return r;
 634         if( !*valid )
 635             return ERROR_SUCCESS;
 636         r = WHERE_VerifyCondition( db, table, cond->u.expr.right, valid );
 637         if( r != ERROR_SUCCESS )
 638             return r;
 639
 640         /* check the type of the comparison */
 641         if( ( cond->u.expr.left->type == EXPR_SVAL ) ||
 642             ( cond->u.expr.left->type == EXPR_COL_NUMBER_STRING ) ||
 643             ( cond->u.expr.right->type == EXPR_SVAL ) ||
 644             ( cond->u.expr.right->type == EXPR_COL_NUMBER_STRING ) )
 645         {
 646             switch( cond->u.expr.op )
 647             {
 648             case OP_EQ:
 649             case OP_NE:
 650                 break;
 651             default:
 652                 *valid = FALSE;
 653                 return ERROR_INVALID_PARAMETER;
 654             }
 655
 656             /* FIXME: check we're comparing a string to a column */
 657
 658             cond->type = EXPR_STRCMP;
 659         }
 660
 661         break;
 662     case EXPR_UNARY:
 663         if ( cond->u.expr.left->type != EXPR_COLUMN )
 664         {
 665             *valid = FALSE;
 666             return ERROR_INVALID_PARAMETER;
 667         }
 668         r = WHERE_VerifyCondition( db, table, cond->u.expr.left, valid );
 669         if( r != ERROR_SUCCESS )
 670             return r;
 671         break;
 672     case EXPR_IVAL:
 673         *valid = 1;
 674         cond->type = EXPR_UVAL;
 675         cond->u.uval = cond->u.ival;
 676         break;
 677     case EXPR_WILDCARD:
 678         *valid = 1;
 679         break;
 680     case EXPR_SVAL:
 681         *valid = 1;
 682         break;
 683     default:
 684         ERR("Invalid expression type\n");
 685         *valid = 0;
 686         break;
 687     }
 688
 689     return ERROR_SUCCESS;
 690 }
 691
 692 UINT WHERE_CreateView( MSIDATABASE *db, MSIVIEW **view, MSIVIEW *table,
 693                        struct expr *cond )
 694 {
 695     MSIWHEREVIEW *wv = NULL;
 696     UINT count = 0, r, valid = 0;
 697
 698     TRACE("%p\n", table );
 699
 700     r = table->ops->get_dimensions( table, NULL, &count );
 701     if( r != ERROR_SUCCESS )
 702     {
 703         ERR("can't get table dimensions\n");
 704         return r;
 705     }
 706
 707     if( cond )
 708     {
 709         r = WHERE_VerifyCondition( db, table, cond, &valid );
 710         if( r != ERROR_SUCCESS )
 711             return r;
 712         if( !valid )
 713             return ERROR_FUNCTION_FAILED;
 714     }
 715
 716     wv = msi_alloc_zero( sizeof *wv );
 717     if( !wv )
 718         return ERROR_FUNCTION_FAILED;
 719
 720     /* fill the structure */
 721     wv->view.ops = &where_ops;
 722     msiobj_addref( &db->hdr );
 723     wv->db = db;
 724     wv->table = table;
 725     wv->row_count = 0;
 726     wv->reorder = NULL;
 727     wv->cond = cond;
 728     wv->rec_index = 0;
 729     *view = (MSIVIEW*) wv;
 730
 731     return ERROR_SUCCESS;
 732 }