xref: /sqlite-3.40.0/src/insert.c (revision 7c68d60b)
1 /*
2 ** Copyright (c) 1999, 2000 D. Richard Hipp
3 **
4 ** This program is free software; you can redistribute it and/or
5 ** modify it under the terms of the GNU General Public
6 ** License as published by the Free Software Foundation; either
7 ** version 2 of the License, or (at your option) any later version.
8 **
9 ** This program is distributed in the hope that it will be useful,
10 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
11 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 ** General Public License for more details.
13 **
14 ** You should have received a copy of the GNU General Public
15 ** License along with this library; if not, write to the
16 ** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 ** Boston, MA  02111-1307, USA.
18 **
19 ** Author contact information:
20 **   [email protected]
21 **   http://www.hwaci.com/drh/
22 **
23 *************************************************************************
24 ** This file contains C code routines that are called by the parser
25 ** to handle INSERT statements.
26 **
27 ** $Id: insert.c,v 1.11 2000/06/21 13:59:12 drh Exp $
28 */
29 #include "sqliteInt.h"
30 
31 /*
32 ** This routine is call to handle SQL of the following forms:
33 **
34 **    insert into TABLE (IDLIST) values(EXPRLIST)
35 **    insert into TABLE (IDLIST) select
36 **
37 ** The IDLIST following the table name is always optional.  If omitted,
38 ** then a list of all columns for the table is substituted.  The IDLIST
39 ** appears in the pColumn parameter.  pColumn is NULL if IDLIST is omitted.
40 **
41 ** The pList parameter holds EXPRLIST in the first form of the INSERT
42 ** statement above, and pSelect is NULL.  For the second form, pList is
43 ** NULL and pSelect is a pointer to the select statement used to generate
44 ** data for the insert.
45 */
46 void sqliteInsert(
47   Parse *pParse,        /* Parser context */
48   Token *pTableName,    /* Name of table into which we are inserting */
49   ExprList *pList,      /* List of values to be inserted */
50   Select *pSelect,      /* A SELECT statement to use as the data source */
51   IdList *pColumn       /* Column names corresponding to IDLIST. */
52 ){
53   Table *pTab;          /* The table to insert into */
54   char *zTab;           /* Name of the table into which we are inserting */
55   int i, j, idx;        /* Loop counters */
56   Vdbe *v;              /* Generate code into this virtual machine */
57   Index *pIdx;          /* For looping over indices of the table */
58   int srcTab;           /* Date comes from this temporary cursor if >=0 */
59   int nColumn;          /* Number of columns in the data */
60   int base;             /* First available cursor */
61   int iCont, iBreak;    /* Beginning and end of the loop over srcTab */
62 
63   /* Locate the table into which we will be inserting new information.
64   */
65   zTab = sqliteTableNameFromToken(pTableName);
66   pTab = sqliteFindTable(pParse->db, zTab);
67   sqliteFree(zTab);
68   if( pTab==0 ){
69     sqliteSetNString(&pParse->zErrMsg, "no such table: ", 0,
70         pTableName->z, pTableName->n, 0);
71     pParse->nErr++;
72     goto insert_cleanup;
73   }
74   if( pTab->readOnly ){
75     sqliteSetString(&pParse->zErrMsg, "table ", pTab->zName,
76         " may not be modified", 0);
77     pParse->nErr++;
78     goto insert_cleanup;
79   }
80 
81   /* Allocate a VDBE
82   */
83   v = sqliteGetVdbe(pParse);
84   if( v==0 ) goto insert_cleanup;
85 
86   /* Figure out how many columns of data are supplied.  If the data
87   ** is comming from a SELECT statement, then this step has to generate
88   ** all the code to implement the SELECT statement and leave the data
89   ** in a temporary table.  If data is coming from an expression list,
90   ** then we just have to count the number of expressions.
91   */
92   if( pSelect ){
93     int rc;
94     srcTab = pParse->nTab++;
95     sqliteVdbeAddOp(v, OP_Open, srcTab, 1, 0, 0);
96     rc = sqliteSelect(pParse, pSelect, SRT_Table, srcTab);
97     if( rc ) goto insert_cleanup;
98     assert( pSelect->pEList );
99     nColumn = pSelect->pEList->nExpr;
100   }else{
101     srcTab = -1;
102     assert( pList );
103     nColumn = pList->nExpr;
104   }
105 
106   /* Make sure the number of columns in the source data matches the number
107   ** of columns to be inserted into the table.
108   */
109   if( pColumn==0 && nColumn!=pTab->nCol ){
110     char zNum1[30];
111     char zNum2[30];
112     sprintf(zNum1,"%d", nColumn);
113     sprintf(zNum2,"%d", pTab->nCol);
114     sqliteSetString(&pParse->zErrMsg, "table ", pTab->zName,
115        " has ", zNum2, " columns but ",
116        zNum1, " values were supplied", 0);
117     pParse->nErr++;
118     goto insert_cleanup;
119   }
120   if( pColumn!=0 && nColumn!=pColumn->nId ){
121     char zNum1[30];
122     char zNum2[30];
123     sprintf(zNum1,"%d", nColumn);
124     sprintf(zNum2,"%d", pColumn->nId);
125     sqliteSetString(&pParse->zErrMsg, zNum1, " values for ",
126        zNum2, " columns", 0);
127     pParse->nErr++;
128     goto insert_cleanup;
129   }
130 
131   /* If the INSERT statement included an IDLIST term, then make sure
132   ** all elements of the IDLIST really are columns of the table and
133   ** remember the column indices.
134   */
135   if( pColumn ){
136     for(i=0; i<pColumn->nId; i++){
137       pColumn->a[i].idx = -1;
138     }
139     for(i=0; i<pColumn->nId; i++){
140       for(j=0; j<pTab->nCol; j++){
141         if( sqliteStrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
142           pColumn->a[i].idx = j;
143           break;
144         }
145       }
146       if( j>=pTab->nCol ){
147         sqliteSetString(&pParse->zErrMsg, "table ", pTab->zName,
148            " has no column named ", pColumn->a[i].zName, 0);
149         pParse->nErr++;
150         goto insert_cleanup;
151       }
152     }
153   }
154 
155   /* Open cursors into the table that is received the new data and
156   ** all indices of that table.
157   */
158   base = pParse->nTab;
159   sqliteVdbeAddOp(v, OP_Open, base, 1, pTab->zName, 0);
160   for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
161     sqliteVdbeAddOp(v, OP_Open, idx+base, 1, pIdx->zName, 0);
162   }
163 
164   /* If the data source is a SELECT statement, then we have to create
165   ** a loop because there might be multiple rows of data.  If the data
166   ** source is an expression list, then exactly one row will be inserted
167   ** and the loop is not used.
168   */
169   if( srcTab>=0 ){
170     sqliteVdbeAddOp(v, OP_Rewind, srcTab, 0, 0, 0);
171     iBreak = sqliteVdbeMakeLabel(v);
172     iCont = sqliteVdbeAddOp(v, OP_Next, srcTab, iBreak, 0, 0);
173   }
174 
175   /* Create a new entry in the table and fill it with data.
176   */
177   sqliteVdbeAddOp(v, OP_New, 0, 0, 0, 0);
178   if( pTab->pIndex ){
179     sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
180   }
181   for(i=0; i<pTab->nCol; i++){
182     if( pColumn==0 ){
183       j = i;
184     }else{
185       for(j=0; j<pColumn->nId; j++){
186         if( pColumn->a[j].idx==i ) break;
187       }
188     }
189     if( pColumn && j>=pColumn->nId ){
190       char *zDflt = pTab->aCol[i].zDflt;
191       if( zDflt==0 ){
192         sqliteVdbeAddOp(v, OP_Null, 0, 0, 0, 0);
193       }else{
194         sqliteVdbeAddOp(v, OP_String, 0, 0, zDflt, 0);
195       }
196     }else if( srcTab>=0 ){
197       sqliteVdbeAddOp(v, OP_Field, srcTab, i, 0, 0);
198     }else{
199       sqliteExprCode(pParse, pList->a[j].pExpr);
200     }
201   }
202   sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0, 0, 0);
203   sqliteVdbeAddOp(v, OP_Put, base, 0, 0, 0);
204 
205   /* Create appropriate entries for the new data row in all indices
206   ** of the table.
207   */
208   for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
209     if( pIdx->pNext ){
210       sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
211     }
212     for(i=0; i<pIdx->nColumn; i++){
213       int idx = pIdx->aiColumn[i];
214       if( pColumn==0 ){
215         j = idx;
216       }else{
217         for(j=0; j<pColumn->nId; j++){
218           if( pColumn->a[j].idx==idx ) break;
219         }
220       }
221       if( pColumn && j>=pColumn->nId ){
222         char *zDflt = pTab->aCol[idx].zDflt;
223         if( zDflt==0 ){
224           sqliteVdbeAddOp(v, OP_Null, 0, 0, 0, 0);
225         }else{
226           sqliteVdbeAddOp(v, OP_String, 0, 0, zDflt, 0);
227         }
228       }else if( srcTab>=0 ){
229         sqliteVdbeAddOp(v, OP_Field, srcTab, idx, 0, 0);
230       }else{
231         sqliteExprCode(pParse, pList->a[j].pExpr);
232       }
233     }
234     sqliteVdbeAddOp(v, OP_MakeKey, pIdx->nColumn, 0, 0, 0);
235     sqliteVdbeAddOp(v, OP_PutIdx, idx+base, 0, 0, 0);
236   }
237 
238   /* The bottom of the loop, if the data source is a SELECT statement
239   */
240   if( srcTab>=0 ){
241     sqliteVdbeAddOp(v, OP_Goto, 0, iCont, 0, 0);
242     sqliteVdbeAddOp(v, OP_Noop, 0, 0, 0, iBreak);
243   }
244 
245 insert_cleanup:
246   if( pList ) sqliteExprListDelete(pList);
247   if( pSelect ) sqliteSelectDelete(pSelect);
248   sqliteIdListDelete(pColumn);
249 }
250