xref: /illumos-gate/usr/src/lib/libsqlite/src/insert.c (revision 002c70ff32f5df6f93c15f88d351ce26443e6ee7)
1 
2 #pragma ident	"%Z%%M%	%I%	%E% SMI"
3 
4 /*
5 ** 2001 September 15
6 **
7 ** The author disclaims copyright to this source code.  In place of
8 ** a legal notice, here is a blessing:
9 **
10 **    May you do good and not evil.
11 **    May you find forgiveness for yourself and forgive others.
12 **    May you share freely, never taking more than you give.
13 **
14 *************************************************************************
15 ** This file contains C code routines that are called by the parser
16 ** to handle INSERT statements in SQLite.
17 **
18 ** $Id: insert.c,v 1.94 2004/02/24 01:05:33 drh Exp $
19 */
20 #include "sqliteInt.h"
21 
22 /*
23 ** This routine is call to handle SQL of the following forms:
24 **
25 **    insert into TABLE (IDLIST) values(EXPRLIST)
26 **    insert into TABLE (IDLIST) select
27 **
28 ** The IDLIST following the table name is always optional.  If omitted,
29 ** then a list of all columns for the table is substituted.  The IDLIST
30 ** appears in the pColumn parameter.  pColumn is NULL if IDLIST is omitted.
31 **
32 ** The pList parameter holds EXPRLIST in the first form of the INSERT
33 ** statement above, and pSelect is NULL.  For the second form, pList is
34 ** NULL and pSelect is a pointer to the select statement used to generate
35 ** data for the insert.
36 **
37 ** The code generated follows one of three templates.  For a simple
38 ** select with data coming from a VALUES clause, the code executes
39 ** once straight down through.  The template looks like this:
40 **
41 **         open write cursor to <table> and its indices
42 **         puts VALUES clause expressions onto the stack
43 **         write the resulting record into <table>
44 **         cleanup
45 **
46 ** If the statement is of the form
47 **
48 **   INSERT INTO <table> SELECT ...
49 **
50 ** And the SELECT clause does not read from <table> at any time, then
51 ** the generated code follows this template:
52 **
53 **         goto B
54 **      A: setup for the SELECT
55 **         loop over the tables in the SELECT
56 **           gosub C
57 **         end loop
58 **         cleanup after the SELECT
59 **         goto D
60 **      B: open write cursor to <table> and its indices
61 **         goto A
62 **      C: insert the select result into <table>
63 **         return
64 **      D: cleanup
65 **
66 ** The third template is used if the insert statement takes its
67 ** values from a SELECT but the data is being inserted into a table
68 ** that is also read as part of the SELECT.  In the third form,
69 ** we have to use a intermediate table to store the results of
70 ** the select.  The template is like this:
71 **
72 **         goto B
73 **      A: setup for the SELECT
74 **         loop over the tables in the SELECT
75 **           gosub C
76 **         end loop
77 **         cleanup after the SELECT
78 **         goto D
79 **      C: insert the select result into the intermediate table
80 **         return
81 **      B: open a cursor to an intermediate table
82 **         goto A
83 **      D: open write cursor to <table> and its indices
84 **         loop over the intermediate table
85 **           transfer values form intermediate table into <table>
86 **         end the loop
87 **         cleanup
88 */
89 void sqliteInsert(
90   Parse *pParse,        /* Parser context */
91   SrcList *pTabList,    /* Name of table into which we are inserting */
92   ExprList *pList,      /* List of values to be inserted */
93   Select *pSelect,      /* A SELECT statement to use as the data source */
94   IdList *pColumn,      /* Column names corresponding to IDLIST. */
95   int onError           /* How to handle constraint errors */
96 ){
97   Table *pTab;          /* The table to insert into */
98   char *zTab;           /* Name of the table into which we are inserting */
99   const char *zDb;      /* Name of the database holding this table */
100   int i, j, idx;        /* Loop counters */
101   Vdbe *v;              /* Generate code into this virtual machine */
102   Index *pIdx;          /* For looping over indices of the table */
103   int nColumn;          /* Number of columns in the data */
104   int base;             /* VDBE Cursor number for pTab */
105   int iCont, iBreak;    /* Beginning and end of the loop over srcTab */
106   sqlite *db;           /* The main database structure */
107   int keyColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */
108   int endOfLoop;        /* Label for the end of the insertion loop */
109   int useTempTable;     /* Store SELECT results in intermediate table */
110   int srcTab;           /* Data comes from this temporary cursor if >=0 */
111   int iSelectLoop;      /* Address of code that implements the SELECT */
112   int iCleanup;         /* Address of the cleanup code */
113   int iInsertBlock;     /* Address of the subroutine used to insert data */
114   int iCntMem;          /* Memory cell used for the row counter */
115   int isView;           /* True if attempting to insert into a view */
116 
117   int row_triggers_exist = 0; /* True if there are FOR EACH ROW triggers */
118   int before_triggers;        /* True if there are BEFORE triggers */
119   int after_triggers;         /* True if there are AFTER triggers */
120   int newIdx = -1;            /* Cursor for the NEW table */
121 
122   if( pParse->nErr || sqlite_malloc_failed ) goto insert_cleanup;
123   db = pParse->db;
124 
125   /* Locate the table into which we will be inserting new information.
126   */
127   assert( pTabList->nSrc==1 );
128   zTab = pTabList->a[0].zName;
129   if( zTab==0 ) goto insert_cleanup;
130   pTab = sqliteSrcListLookup(pParse, pTabList);
131   if( pTab==0 ){
132     goto insert_cleanup;
133   }
134   assert( pTab->iDb<db->nDb );
135   zDb = db->aDb[pTab->iDb].zName;
136   if( sqliteAuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb) ){
137     goto insert_cleanup;
138   }
139 
140   /* Ensure that:
141   *  (a) the table is not read-only,
142   *  (b) that if it is a view then ON INSERT triggers exist
143   */
144   before_triggers = sqliteTriggersExist(pParse, pTab->pTrigger, TK_INSERT,
145                                        TK_BEFORE, TK_ROW, 0);
146   after_triggers = sqliteTriggersExist(pParse, pTab->pTrigger, TK_INSERT,
147                                        TK_AFTER, TK_ROW, 0);
148   row_triggers_exist = before_triggers || after_triggers;
149   isView = pTab->pSelect!=0;
150   if( sqliteIsReadOnly(pParse, pTab, before_triggers) ){
151     goto insert_cleanup;
152   }
153   if( pTab==0 ) goto insert_cleanup;
154 
155   /* If pTab is really a view, make sure it has been initialized.
156   */
157   if( isView && sqliteViewGetColumnNames(pParse, pTab) ){
158     goto insert_cleanup;
159   }
160 
161   /* Allocate a VDBE
162   */
163   v = sqliteGetVdbe(pParse);
164   if( v==0 ) goto insert_cleanup;
165   sqliteBeginWriteOperation(pParse, pSelect || row_triggers_exist, pTab->iDb);
166 
167   /* if there are row triggers, allocate a temp table for new.* references. */
168   if( row_triggers_exist ){
169     newIdx = pParse->nTab++;
170   }
171 
172   /* Figure out how many columns of data are supplied.  If the data
173   ** is coming from a SELECT statement, then this step also generates
174   ** all the code to implement the SELECT statement and invoke a subroutine
175   ** to process each row of the result. (Template 2.) If the SELECT
176   ** statement uses the the table that is being inserted into, then the
177   ** subroutine is also coded here.  That subroutine stores the SELECT
178   ** results in a temporary table. (Template 3.)
179   */
180   if( pSelect ){
181     /* Data is coming from a SELECT.  Generate code to implement that SELECT
182     */
183     int rc, iInitCode;
184     iInitCode = sqliteVdbeAddOp(v, OP_Goto, 0, 0);
185     iSelectLoop = sqliteVdbeCurrentAddr(v);
186     iInsertBlock = sqliteVdbeMakeLabel(v);
187     rc = sqliteSelect(pParse, pSelect, SRT_Subroutine, iInsertBlock, 0,0,0);
188     if( rc || pParse->nErr || sqlite_malloc_failed ) goto insert_cleanup;
189     iCleanup = sqliteVdbeMakeLabel(v);
190     sqliteVdbeAddOp(v, OP_Goto, 0, iCleanup);
191     assert( pSelect->pEList );
192     nColumn = pSelect->pEList->nExpr;
193 
194     /* Set useTempTable to TRUE if the result of the SELECT statement
195     ** should be written into a temporary table.  Set to FALSE if each
196     ** row of the SELECT can be written directly into the result table.
197     **
198     ** A temp table must be used if the table being updated is also one
199     ** of the tables being read by the SELECT statement.  Also use a
200     ** temp table in the case of row triggers.
201     */
202     if( row_triggers_exist ){
203       useTempTable = 1;
204     }else{
205       int addr = sqliteVdbeFindOp(v, OP_OpenRead, pTab->tnum);
206       useTempTable = 0;
207       if( addr>0 ){
208         VdbeOp *pOp = sqliteVdbeGetOp(v, addr-2);
209         if( pOp->opcode==OP_Integer && pOp->p1==pTab->iDb ){
210           useTempTable = 1;
211         }
212       }
213     }
214 
215     if( useTempTable ){
216       /* Generate the subroutine that SELECT calls to process each row of
217       ** the result.  Store the result in a temporary table
218       */
219       srcTab = pParse->nTab++;
220       sqliteVdbeResolveLabel(v, iInsertBlock);
221       sqliteVdbeAddOp(v, OP_MakeRecord, nColumn, 0);
222       sqliteVdbeAddOp(v, OP_NewRecno, srcTab, 0);
223       sqliteVdbeAddOp(v, OP_Pull, 1, 0);
224       sqliteVdbeAddOp(v, OP_PutIntKey, srcTab, 0);
225       sqliteVdbeAddOp(v, OP_Return, 0, 0);
226 
227       /* The following code runs first because the GOTO at the very top
228       ** of the program jumps to it.  Create the temporary table, then jump
229       ** back up and execute the SELECT code above.
230       */
231       sqliteVdbeChangeP2(v, iInitCode, sqliteVdbeCurrentAddr(v));
232       sqliteVdbeAddOp(v, OP_OpenTemp, srcTab, 0);
233       sqliteVdbeAddOp(v, OP_Goto, 0, iSelectLoop);
234       sqliteVdbeResolveLabel(v, iCleanup);
235     }else{
236       sqliteVdbeChangeP2(v, iInitCode, sqliteVdbeCurrentAddr(v));
237     }
238   }else{
239     /* This is the case if the data for the INSERT is coming from a VALUES
240     ** clause
241     */
242     SrcList dummy;
243     assert( pList!=0 );
244     srcTab = -1;
245     useTempTable = 0;
246     assert( pList );
247     nColumn = pList->nExpr;
248     dummy.nSrc = 0;
249     for(i=0; i<nColumn; i++){
250       if( sqliteExprResolveIds(pParse, &dummy, 0, pList->a[i].pExpr) ){
251         goto insert_cleanup;
252       }
253       if( sqliteExprCheck(pParse, pList->a[i].pExpr, 0, 0) ){
254         goto insert_cleanup;
255       }
256     }
257   }
258 
259   /* Make sure the number of columns in the source data matches the number
260   ** of columns to be inserted into the table.
261   */
262   if( pColumn==0 && nColumn!=pTab->nCol ){
263     sqliteErrorMsg(pParse,
264        "table %S has %d columns but %d values were supplied",
265        pTabList, 0, pTab->nCol, nColumn);
266     goto insert_cleanup;
267   }
268   if( pColumn!=0 && nColumn!=pColumn->nId ){
269     sqliteErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
270     goto insert_cleanup;
271   }
272 
273   /* If the INSERT statement included an IDLIST term, then make sure
274   ** all elements of the IDLIST really are columns of the table and
275   ** remember the column indices.
276   **
277   ** If the table has an INTEGER PRIMARY KEY column and that column
278   ** is named in the IDLIST, then record in the keyColumn variable
279   ** the index into IDLIST of the primary key column.  keyColumn is
280   ** the index of the primary key as it appears in IDLIST, not as
281   ** is appears in the original table.  (The index of the primary
282   ** key in the original table is pTab->iPKey.)
283   */
284   if( pColumn ){
285     for(i=0; i<pColumn->nId; i++){
286       pColumn->a[i].idx = -1;
287     }
288     for(i=0; i<pColumn->nId; i++){
289       for(j=0; j<pTab->nCol; j++){
290         if( sqliteStrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
291           pColumn->a[i].idx = j;
292           if( j==pTab->iPKey ){
293             keyColumn = i;
294           }
295           break;
296         }
297       }
298       if( j>=pTab->nCol ){
299         if( sqliteIsRowid(pColumn->a[i].zName) ){
300           keyColumn = i;
301         }else{
302           sqliteErrorMsg(pParse, "table %S has no column named %s",
303               pTabList, 0, pColumn->a[i].zName);
304           pParse->nErr++;
305           goto insert_cleanup;
306         }
307       }
308     }
309   }
310 
311   /* If there is no IDLIST term but the table has an integer primary
312   ** key, the set the keyColumn variable to the primary key column index
313   ** in the original table definition.
314   */
315   if( pColumn==0 ){
316     keyColumn = pTab->iPKey;
317   }
318 
319   /* Open the temp table for FOR EACH ROW triggers
320   */
321   if( row_triggers_exist ){
322     sqliteVdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
323   }
324 
325   /* Initialize the count of rows to be inserted
326   */
327   if( db->flags & SQLITE_CountRows ){
328     iCntMem = pParse->nMem++;
329     sqliteVdbeAddOp(v, OP_Integer, 0, 0);
330     sqliteVdbeAddOp(v, OP_MemStore, iCntMem, 1);
331   }
332 
333   /* Open tables and indices if there are no row triggers */
334   if( !row_triggers_exist ){
335     base = pParse->nTab;
336     idx = sqliteOpenTableAndIndices(pParse, pTab, base);
337     pParse->nTab += idx;
338   }
339 
340   /* If the data source is a temporary table, then we have to create
341   ** a loop because there might be multiple rows of data.  If the data
342   ** source is a subroutine call from the SELECT statement, then we need
343   ** to launch the SELECT statement processing.
344   */
345   if( useTempTable ){
346     iBreak = sqliteVdbeMakeLabel(v);
347     sqliteVdbeAddOp(v, OP_Rewind, srcTab, iBreak);
348     iCont = sqliteVdbeCurrentAddr(v);
349   }else if( pSelect ){
350     sqliteVdbeAddOp(v, OP_Goto, 0, iSelectLoop);
351     sqliteVdbeResolveLabel(v, iInsertBlock);
352   }
353 
354   /* Run the BEFORE and INSTEAD OF triggers, if there are any
355   */
356   endOfLoop = sqliteVdbeMakeLabel(v);
357   if( before_triggers ){
358 
359     /* build the NEW.* reference row.  Note that if there is an INTEGER
360     ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
361     ** translated into a unique ID for the row.  But on a BEFORE trigger,
362     ** we do not know what the unique ID will be (because the insert has
363     ** not happened yet) so we substitute a rowid of -1
364     */
365     if( keyColumn<0 ){
366       sqliteVdbeAddOp(v, OP_Integer, -1, 0);
367     }else if( useTempTable ){
368       sqliteVdbeAddOp(v, OP_Column, srcTab, keyColumn);
369     }else if( pSelect ){
370       sqliteVdbeAddOp(v, OP_Dup, nColumn - keyColumn - 1, 1);
371     }else{
372       sqliteExprCode(pParse, pList->a[keyColumn].pExpr);
373       sqliteVdbeAddOp(v, OP_NotNull, -1, sqliteVdbeCurrentAddr(v)+3);
374       sqliteVdbeAddOp(v, OP_Pop, 1, 0);
375       sqliteVdbeAddOp(v, OP_Integer, -1, 0);
376       sqliteVdbeAddOp(v, OP_MustBeInt, 0, 0);
377     }
378 
379     /* Create the new column data
380     */
381     for(i=0; i<pTab->nCol; i++){
382       if( pColumn==0 ){
383         j = i;
384       }else{
385         for(j=0; j<pColumn->nId; j++){
386           if( pColumn->a[j].idx==i ) break;
387         }
388       }
389       if( pColumn && j>=pColumn->nId ){
390         sqliteVdbeOp3(v, OP_String, 0, 0, pTab->aCol[i].zDflt, P3_STATIC);
391       }else if( useTempTable ){
392         sqliteVdbeAddOp(v, OP_Column, srcTab, j);
393       }else if( pSelect ){
394         sqliteVdbeAddOp(v, OP_Dup, nColumn-j-1, 1);
395       }else{
396         sqliteExprCode(pParse, pList->a[j].pExpr);
397       }
398     }
399     sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
400     sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);
401 
402     /* Fire BEFORE or INSTEAD OF triggers */
403     if( sqliteCodeRowTrigger(pParse, TK_INSERT, 0, TK_BEFORE, pTab,
404         newIdx, -1, onError, endOfLoop) ){
405       goto insert_cleanup;
406     }
407   }
408 
409   /* If any triggers exists, the opening of tables and indices is deferred
410   ** until now.
411   */
412   if( row_triggers_exist && !isView ){
413     base = pParse->nTab;
414     idx = sqliteOpenTableAndIndices(pParse, pTab, base);
415     pParse->nTab += idx;
416   }
417 
418   /* Push the record number for the new entry onto the stack.  The
419   ** record number is a randomly generate integer created by NewRecno
420   ** except when the table has an INTEGER PRIMARY KEY column, in which
421   ** case the record number is the same as that column.
422   */
423   if( !isView ){
424     if( keyColumn>=0 ){
425       if( useTempTable ){
426         sqliteVdbeAddOp(v, OP_Column, srcTab, keyColumn);
427       }else if( pSelect ){
428         sqliteVdbeAddOp(v, OP_Dup, nColumn - keyColumn - 1, 1);
429       }else{
430         sqliteExprCode(pParse, pList->a[keyColumn].pExpr);
431       }
432       /* If the PRIMARY KEY expression is NULL, then use OP_NewRecno
433       ** to generate a unique primary key value.
434       */
435       sqliteVdbeAddOp(v, OP_NotNull, -1, sqliteVdbeCurrentAddr(v)+3);
436       sqliteVdbeAddOp(v, OP_Pop, 1, 0);
437       sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
438       sqliteVdbeAddOp(v, OP_MustBeInt, 0, 0);
439     }else{
440       sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
441     }
442 
443     /* Push onto the stack, data for all columns of the new entry, beginning
444     ** with the first column.
445     */
446     for(i=0; i<pTab->nCol; i++){
447       if( i==pTab->iPKey ){
448         /* The value of the INTEGER PRIMARY KEY column is always a NULL.
449         ** Whenever this column is read, the record number will be substituted
450         ** in its place.  So will fill this column with a NULL to avoid
451         ** taking up data space with information that will never be used. */
452         sqliteVdbeAddOp(v, OP_String, 0, 0);
453         continue;
454       }
455       if( pColumn==0 ){
456         j = i;
457       }else{
458         for(j=0; j<pColumn->nId; j++){
459           if( pColumn->a[j].idx==i ) break;
460         }
461       }
462       if( pColumn && j>=pColumn->nId ){
463         sqliteVdbeOp3(v, OP_String, 0, 0, pTab->aCol[i].zDflt, P3_STATIC);
464       }else if( useTempTable ){
465         sqliteVdbeAddOp(v, OP_Column, srcTab, j);
466       }else if( pSelect ){
467         sqliteVdbeAddOp(v, OP_Dup, i+nColumn-j, 1);
468       }else{
469         sqliteExprCode(pParse, pList->a[j].pExpr);
470       }
471     }
472 
473     /* Generate code to check constraints and generate index keys and
474     ** do the insertion.
475     */
476     sqliteGenerateConstraintChecks(pParse, pTab, base, 0, keyColumn>=0,
477                                    0, onError, endOfLoop);
478     sqliteCompleteInsertion(pParse, pTab, base, 0,0,0,
479                             after_triggers ? newIdx : -1);
480   }
481 
482   /* Update the count of rows that are inserted
483   */
484   if( (db->flags & SQLITE_CountRows)!=0 ){
485     sqliteVdbeAddOp(v, OP_MemIncr, iCntMem, 0);
486   }
487 
488   if( row_triggers_exist ){
489     /* Close all tables opened */
490     if( !isView ){
491       sqliteVdbeAddOp(v, OP_Close, base, 0);
492       for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
493         sqliteVdbeAddOp(v, OP_Close, idx+base, 0);
494       }
495     }
496 
497     /* Code AFTER triggers */
498     if( sqliteCodeRowTrigger(pParse, TK_INSERT, 0, TK_AFTER, pTab, newIdx, -1,
499           onError, endOfLoop) ){
500       goto insert_cleanup;
501     }
502   }
503 
504   /* The bottom of the loop, if the data source is a SELECT statement
505   */
506   sqliteVdbeResolveLabel(v, endOfLoop);
507   if( useTempTable ){
508     sqliteVdbeAddOp(v, OP_Next, srcTab, iCont);
509     sqliteVdbeResolveLabel(v, iBreak);
510     sqliteVdbeAddOp(v, OP_Close, srcTab, 0);
511   }else if( pSelect ){
512     sqliteVdbeAddOp(v, OP_Pop, nColumn, 0);
513     sqliteVdbeAddOp(v, OP_Return, 0, 0);
514     sqliteVdbeResolveLabel(v, iCleanup);
515   }
516 
517   if( !row_triggers_exist ){
518     /* Close all tables opened */
519     sqliteVdbeAddOp(v, OP_Close, base, 0);
520     for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
521       sqliteVdbeAddOp(v, OP_Close, idx+base, 0);
522     }
523   }
524 
525   sqliteVdbeAddOp(v, OP_SetCounts, 0, 0);
526   sqliteEndWriteOperation(pParse);
527 
528   /*
529   ** Return the number of rows inserted.
530   */
531   if( db->flags & SQLITE_CountRows ){
532     sqliteVdbeOp3(v, OP_ColumnName, 0, 1, "rows inserted", P3_STATIC);
533     sqliteVdbeAddOp(v, OP_MemLoad, iCntMem, 0);
534     sqliteVdbeAddOp(v, OP_Callback, 1, 0);
535   }
536 
537 insert_cleanup:
538   sqliteSrcListDelete(pTabList);
539   if( pList ) sqliteExprListDelete(pList);
540   if( pSelect ) sqliteSelectDelete(pSelect);
541   sqliteIdListDelete(pColumn);
542 }
543 
544 /*
545 ** Generate code to do a constraint check prior to an INSERT or an UPDATE.
546 **
547 ** When this routine is called, the stack contains (from bottom to top)
548 ** the following values:
549 **
550 **    1.  The recno of the row to be updated before the update.  This
551 **        value is omitted unless we are doing an UPDATE that involves a
552 **        change to the record number.
553 **
554 **    2.  The recno of the row after the update.
555 **
556 **    3.  The data in the first column of the entry after the update.
557 **
558 **    i.  Data from middle columns...
559 **
560 **    N.  The data in the last column of the entry after the update.
561 **
562 ** The old recno shown as entry (1) above is omitted unless both isUpdate
563 ** and recnoChng are 1.  isUpdate is true for UPDATEs and false for
564 ** INSERTs and recnoChng is true if the record number is being changed.
565 **
566 ** The code generated by this routine pushes additional entries onto
567 ** the stack which are the keys for new index entries for the new record.
568 ** The order of index keys is the same as the order of the indices on
569 ** the pTable->pIndex list.  A key is only created for index i if
570 ** aIdxUsed!=0 and aIdxUsed[i]!=0.
571 **
572 ** This routine also generates code to check constraints.  NOT NULL,
573 ** CHECK, and UNIQUE constraints are all checked.  If a constraint fails,
574 ** then the appropriate action is performed.  There are five possible
575 ** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
576 **
577 **  Constraint type  Action       What Happens
578 **  ---------------  ----------   ----------------------------------------
579 **  any              ROLLBACK     The current transaction is rolled back and
580 **                                sqlite_exec() returns immediately with a
581 **                                return code of SQLITE_CONSTRAINT.
582 **
583 **  any              ABORT        Back out changes from the current command
584 **                                only (do not do a complete rollback) then
585 **                                cause sqlite_exec() to return immediately
586 **                                with SQLITE_CONSTRAINT.
587 **
588 **  any              FAIL         Sqlite_exec() returns immediately with a
589 **                                return code of SQLITE_CONSTRAINT.  The
590 **                                transaction is not rolled back and any
591 **                                prior changes are retained.
592 **
593 **  any              IGNORE       The record number and data is popped from
594 **                                the stack and there is an immediate jump
595 **                                to label ignoreDest.
596 **
597 **  NOT NULL         REPLACE      The NULL value is replace by the default
598 **                                value for that column.  If the default value
599 **                                is NULL, the action is the same as ABORT.
600 **
601 **  UNIQUE           REPLACE      The other row that conflicts with the row
602 **                                being inserted is removed.
603 **
604 **  CHECK            REPLACE      Illegal.  The results in an exception.
605 **
606 ** Which action to take is determined by the overrideError parameter.
607 ** Or if overrideError==OE_Default, then the pParse->onError parameter
608 ** is used.  Or if pParse->onError==OE_Default then the onError value
609 ** for the constraint is used.
610 **
611 ** The calling routine must open a read/write cursor for pTab with
612 ** cursor number "base".  All indices of pTab must also have open
613 ** read/write cursors with cursor number base+i for the i-th cursor.
614 ** Except, if there is no possibility of a REPLACE action then
615 ** cursors do not need to be open for indices where aIdxUsed[i]==0.
616 **
617 ** If the isUpdate flag is true, it means that the "base" cursor is
618 ** initially pointing to an entry that is being updated.  The isUpdate
619 ** flag causes extra code to be generated so that the "base" cursor
620 ** is still pointing at the same entry after the routine returns.
621 ** Without the isUpdate flag, the "base" cursor might be moved.
622 */
623 void sqliteGenerateConstraintChecks(
624   Parse *pParse,      /* The parser context */
625   Table *pTab,        /* the table into which we are inserting */
626   int base,           /* Index of a read/write cursor pointing at pTab */
627   char *aIdxUsed,     /* Which indices are used.  NULL means all are used */
628   int recnoChng,      /* True if the record number will change */
629   int isUpdate,       /* True for UPDATE, False for INSERT */
630   int overrideError,  /* Override onError to this if not OE_Default */
631   int ignoreDest      /* Jump to this label on an OE_Ignore resolution */
632 ){
633   int i;
634   Vdbe *v;
635   int nCol;
636   int onError;
637   int addr;
638   int extra;
639   int iCur;
640   Index *pIdx;
641   int seenReplace = 0;
642   int jumpInst1, jumpInst2;
643   int contAddr;
644   int hasTwoRecnos = (isUpdate && recnoChng);
645 
646   v = sqliteGetVdbe(pParse);
647   assert( v!=0 );
648   assert( pTab->pSelect==0 );  /* This table is not a VIEW */
649   nCol = pTab->nCol;
650 
651   /* Test all NOT NULL constraints.
652   */
653   for(i=0; i<nCol; i++){
654     if( i==pTab->iPKey ){
655       continue;
656     }
657     onError = pTab->aCol[i].notNull;
658     if( onError==OE_None ) continue;
659     if( overrideError!=OE_Default ){
660       onError = overrideError;
661     }else if( pParse->db->onError!=OE_Default ){
662       onError = pParse->db->onError;
663     }else if( onError==OE_Default ){
664       onError = OE_Abort;
665     }
666     if( onError==OE_Replace && pTab->aCol[i].zDflt==0 ){
667       onError = OE_Abort;
668     }
669     sqliteVdbeAddOp(v, OP_Dup, nCol-1-i, 1);
670     addr = sqliteVdbeAddOp(v, OP_NotNull, 1, 0);
671     switch( onError ){
672       case OE_Rollback:
673       case OE_Abort:
674       case OE_Fail: {
675         char *zMsg = 0;
676         sqliteVdbeAddOp(v, OP_Halt, SQLITE_CONSTRAINT, onError);
677         sqliteSetString(&zMsg, pTab->zName, ".", pTab->aCol[i].zName,
678                         " may not be NULL", (char*)0);
679         sqliteVdbeChangeP3(v, -1, zMsg, P3_DYNAMIC);
680         break;
681       }
682       case OE_Ignore: {
683         sqliteVdbeAddOp(v, OP_Pop, nCol+1+hasTwoRecnos, 0);
684         sqliteVdbeAddOp(v, OP_Goto, 0, ignoreDest);
685         break;
686       }
687       case OE_Replace: {
688         sqliteVdbeOp3(v, OP_String, 0, 0, pTab->aCol[i].zDflt, P3_STATIC);
689         sqliteVdbeAddOp(v, OP_Push, nCol-i, 0);
690         break;
691       }
692       default: assert(0);
693     }
694     sqliteVdbeChangeP2(v, addr, sqliteVdbeCurrentAddr(v));
695   }
696 
697   /* Test all CHECK constraints
698   */
699   /**** TBD ****/
700 
701   /* If we have an INTEGER PRIMARY KEY, make sure the primary key
702   ** of the new record does not previously exist.  Except, if this
703   ** is an UPDATE and the primary key is not changing, that is OK.
704   */
705   if( recnoChng ){
706     onError = pTab->keyConf;
707     if( overrideError!=OE_Default ){
708       onError = overrideError;
709     }else if( pParse->db->onError!=OE_Default ){
710       onError = pParse->db->onError;
711     }else if( onError==OE_Default ){
712       onError = OE_Abort;
713     }
714 
715     if( isUpdate ){
716       sqliteVdbeAddOp(v, OP_Dup, nCol+1, 1);
717       sqliteVdbeAddOp(v, OP_Dup, nCol+1, 1);
718       jumpInst1 = sqliteVdbeAddOp(v, OP_Eq, 0, 0);
719     }
720     sqliteVdbeAddOp(v, OP_Dup, nCol, 1);
721     jumpInst2 = sqliteVdbeAddOp(v, OP_NotExists, base, 0);
722     switch( onError ){
723       default: {
724         onError = OE_Abort;
725         /* Fall thru into the next case */
726       }
727       case OE_Rollback:
728       case OE_Abort:
729       case OE_Fail: {
730         sqliteVdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, onError,
731                          "PRIMARY KEY must be unique", P3_STATIC);
732         break;
733       }
734       case OE_Replace: {
735         sqliteGenerateRowIndexDelete(pParse->db, v, pTab, base, 0);
736         if( isUpdate ){
737           sqliteVdbeAddOp(v, OP_Dup, nCol+hasTwoRecnos, 1);
738           sqliteVdbeAddOp(v, OP_MoveTo, base, 0);
739         }
740         seenReplace = 1;
741         break;
742       }
743       case OE_Ignore: {
744         assert( seenReplace==0 );
745         sqliteVdbeAddOp(v, OP_Pop, nCol+1+hasTwoRecnos, 0);
746         sqliteVdbeAddOp(v, OP_Goto, 0, ignoreDest);
747         break;
748       }
749     }
750     contAddr = sqliteVdbeCurrentAddr(v);
751     sqliteVdbeChangeP2(v, jumpInst2, contAddr);
752     if( isUpdate ){
753       sqliteVdbeChangeP2(v, jumpInst1, contAddr);
754       sqliteVdbeAddOp(v, OP_Dup, nCol+1, 1);
755       sqliteVdbeAddOp(v, OP_MoveTo, base, 0);
756     }
757   }
758 
759   /* Test all UNIQUE constraints by creating entries for each UNIQUE
760   ** index and making sure that duplicate entries do not already exist.
761   ** Add the new records to the indices as we go.
762   */
763   extra = -1;
764   for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
765     if( aIdxUsed && aIdxUsed[iCur]==0 ) continue;  /* Skip unused indices */
766     extra++;
767 
768     /* Create a key for accessing the index entry */
769     sqliteVdbeAddOp(v, OP_Dup, nCol+extra, 1);
770     for(i=0; i<pIdx->nColumn; i++){
771       int idx = pIdx->aiColumn[i];
772       if( idx==pTab->iPKey ){
773         sqliteVdbeAddOp(v, OP_Dup, i+extra+nCol+1, 1);
774       }else{
775         sqliteVdbeAddOp(v, OP_Dup, i+extra+nCol-idx, 1);
776       }
777     }
778     jumpInst1 = sqliteVdbeAddOp(v, OP_MakeIdxKey, pIdx->nColumn, 0);
779     if( pParse->db->file_format>=4 ) sqliteAddIdxKeyType(v, pIdx);
780 
781     /* Find out what action to take in case there is an indexing conflict */
782     onError = pIdx->onError;
783     if( onError==OE_None ) continue;  /* pIdx is not a UNIQUE index */
784     if( overrideError!=OE_Default ){
785       onError = overrideError;
786     }else if( pParse->db->onError!=OE_Default ){
787       onError = pParse->db->onError;
788     }else if( onError==OE_Default ){
789       onError = OE_Abort;
790     }
791     if( seenReplace ){
792       if( onError==OE_Ignore ) onError = OE_Replace;
793       else if( onError==OE_Fail ) onError = OE_Abort;
794     }
795 
796 
797     /* Check to see if the new index entry will be unique */
798     sqliteVdbeAddOp(v, OP_Dup, extra+nCol+1+hasTwoRecnos, 1);
799     jumpInst2 = sqliteVdbeAddOp(v, OP_IsUnique, base+iCur+1, 0);
800 
801     /* Generate code that executes if the new index entry is not unique */
802     switch( onError ){
803       case OE_Rollback:
804       case OE_Abort:
805       case OE_Fail: {
806         int j, n1, n2;
807         char zErrMsg[200];
808         strcpy(zErrMsg, pIdx->nColumn>1 ? "columns " : "column ");
809         n1 = strlen(zErrMsg);
810         for(j=0; j<pIdx->nColumn && n1<sizeof(zErrMsg)-30; j++){
811           char *zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
812           n2 = strlen(zCol);
813           if( j>0 ){
814             strcpy(&zErrMsg[n1], ", ");
815             n1 += 2;
816           }
817           if( n1+n2>sizeof(zErrMsg)-30 ){
818             strcpy(&zErrMsg[n1], "...");
819             n1 += 3;
820             break;
821           }else{
822             strcpy(&zErrMsg[n1], zCol);
823             n1 += n2;
824           }
825         }
826         strcpy(&zErrMsg[n1],
827             pIdx->nColumn>1 ? " are not unique" : " is not unique");
828         sqliteVdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, onError, zErrMsg, 0);
829         break;
830       }
831       case OE_Ignore: {
832         assert( seenReplace==0 );
833         sqliteVdbeAddOp(v, OP_Pop, nCol+extra+3+hasTwoRecnos, 0);
834         sqliteVdbeAddOp(v, OP_Goto, 0, ignoreDest);
835         break;
836       }
837       case OE_Replace: {
838         sqliteGenerateRowDelete(pParse->db, v, pTab, base, 0);
839         if( isUpdate ){
840           sqliteVdbeAddOp(v, OP_Dup, nCol+extra+1+hasTwoRecnos, 1);
841           sqliteVdbeAddOp(v, OP_MoveTo, base, 0);
842         }
843         seenReplace = 1;
844         break;
845       }
846       default: assert(0);
847     }
848     contAddr = sqliteVdbeCurrentAddr(v);
849 #if NULL_DISTINCT_FOR_UNIQUE
850     sqliteVdbeChangeP2(v, jumpInst1, contAddr);
851 #endif
852     sqliteVdbeChangeP2(v, jumpInst2, contAddr);
853   }
854 }
855 
856 /*
857 ** This routine generates code to finish the INSERT or UPDATE operation
858 ** that was started by a prior call to sqliteGenerateConstraintChecks.
859 ** The stack must contain keys for all active indices followed by data
860 ** and the recno for the new entry.  This routine creates the new
861 ** entries in all indices and in the main table.
862 **
863 ** The arguments to this routine should be the same as the first six
864 ** arguments to sqliteGenerateConstraintChecks.
865 */
866 void sqliteCompleteInsertion(
867   Parse *pParse,      /* The parser context */
868   Table *pTab,        /* the table into which we are inserting */
869   int base,           /* Index of a read/write cursor pointing at pTab */
870   char *aIdxUsed,     /* Which indices are used.  NULL means all are used */
871   int recnoChng,      /* True if the record number will change */
872   int isUpdate,       /* True for UPDATE, False for INSERT */
873   int newIdx          /* Index of NEW table for triggers.  -1 if none */
874 ){
875   int i;
876   Vdbe *v;
877   int nIdx;
878   Index *pIdx;
879 
880   v = sqliteGetVdbe(pParse);
881   assert( v!=0 );
882   assert( pTab->pSelect==0 );  /* This table is not a VIEW */
883   for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
884   for(i=nIdx-1; i>=0; i--){
885     if( aIdxUsed && aIdxUsed[i]==0 ) continue;
886     sqliteVdbeAddOp(v, OP_IdxPut, base+i+1, 0);
887   }
888   sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
889   if( newIdx>=0 ){
890     sqliteVdbeAddOp(v, OP_Dup, 1, 0);
891     sqliteVdbeAddOp(v, OP_Dup, 1, 0);
892     sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);
893   }
894   sqliteVdbeAddOp(v, OP_PutIntKey, base,
895     (pParse->trigStack?0:OPFLAG_NCHANGE) |
896     (isUpdate?0:OPFLAG_LASTROWID) | OPFLAG_CSCHANGE);
897   if( isUpdate && recnoChng ){
898     sqliteVdbeAddOp(v, OP_Pop, 1, 0);
899   }
900 }
901 
902 /*
903 ** Generate code that will open write cursors for a table and for all
904 ** indices of that table.  The "base" parameter is the cursor number used
905 ** for the table.  Indices are opened on subsequent cursors.
906 **
907 ** Return the total number of cursors opened.  This is always at least
908 ** 1 (for the main table) plus more for each cursor.
909 */
910 int sqliteOpenTableAndIndices(Parse *pParse, Table *pTab, int base){
911   int i;
912   Index *pIdx;
913   Vdbe *v = sqliteGetVdbe(pParse);
914   assert( v!=0 );
915   sqliteVdbeAddOp(v, OP_Integer, pTab->iDb, 0);
916   sqliteVdbeOp3(v, OP_OpenWrite, base, pTab->tnum, pTab->zName, P3_STATIC);
917   for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
918     sqliteVdbeAddOp(v, OP_Integer, pIdx->iDb, 0);
919     sqliteVdbeOp3(v, OP_OpenWrite, i+base, pIdx->tnum, pIdx->zName, P3_STATIC);
920   }
921   return i;
922 }
923