1/*
2** 2001 September 15
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 the sqlite3_get_table() and sqlite3_free_table()
13** interface routines. These are just wrappers around the main
14** interface routine of sqlite3_exec().
15**
16** These routines are in a separate files so that they will not be linked
17** if they are not used.
18*/
19#include "sqliteInt.h"
20
21#ifndef SQLITE_OMIT_GET_TABLE
22
23/*
24** This structure is used to pass data from sqlite3_get_table() through
25** to the callback function is uses to build the result.
26*/
27typedef struct TabResult {
28 char **azResult; /* Accumulated output */
29 char *zErrMsg; /* Error message text, if an error occurs */
30 u32 nAlloc; /* Slots allocated for azResult[] */
31 u32 nRow; /* Number of rows in the result */
32 u32 nColumn; /* Number of columns in the result */
33 u32 nData; /* Slots used in azResult[]. (nRow+1)*nColumn */
34 int rc; /* Return code from sqlite3_exec() */
35} TabResult;
36
37/*
38** This routine is called once for each row in the result table. Its job
39** is to fill in the TabResult structure appropriately, allocating new
40** memory as necessary.
41*/
42static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
43 TabResult *p = (TabResult*)pArg; /* Result accumulator */
44 int need; /* Slots needed in p->azResult[] */
45 int i; /* Loop counter */
46 char *z; /* A single column of result */
47
48 /* Make sure there is enough space in p->azResult to hold everything
49 ** we need to remember from this invocation of the callback.
50 */
51 if( p->nRow==0 && argv!=0 ){
52 need = nCol*2;
53 }else{
54 need = nCol;
55 }
56 if( p->nData + need > p->nAlloc ){
57 char **azNew;
58 p->nAlloc = p->nAlloc*2 + need;
59 azNew = sqlite3Realloc( p->azResult, sizeof(char*)*p->nAlloc );
60 if( azNew==0 ) goto malloc_failed;
61 p->azResult = azNew;
62 }
63
64 /* If this is the first row, then generate an extra row containing
65 ** the names of all columns.
66 */
67 if( p->nRow==0 ){
68 p->nColumn = nCol;
69 for(i=0; i<nCol; i++){
70 z = sqlite3_mprintf("%s", colv[i]);
71 if( z==0 ) goto malloc_failed;
72 p->azResult[p->nData++] = z;
73 }
74 }else if( (int)p->nColumn!=nCol ){
75 sqlite3_free(p->zErrMsg);
76 p->zErrMsg = sqlite3_mprintf(
77 "sqlite3_get_table() called with two or more incompatible queries"
78 );
79 p->rc = SQLITE_ERROR;
80 return 1;
81 }
82
83 /* Copy over the row data
84 */
85 if( argv!=0 ){
86 for(i=0; i<nCol; i++){
87 if( argv[i]==0 ){
88 z = 0;
89 }else{
90 int n = sqlite3Strlen30(argv[i])+1;
91 z = sqlite3_malloc64( n );
92 if( z==0 ) goto malloc_failed;
93 memcpy(z, argv[i], n);
94 }
95 p->azResult[p->nData++] = z;
96 }
97 p->nRow++;
98 }
99 return 0;
100
101malloc_failed:
102 p->rc = SQLITE_NOMEM_BKPT;
103 return 1;
104}
105
106/*
107** Query the database. But instead of invoking a callback for each row,
108** malloc() for space to hold the result and return the entire results
109** at the conclusion of the call.
110**
111** The result that is written to ***pazResult is held in memory obtained
112** from malloc(). But the caller cannot free this memory directly.
113** Instead, the entire table should be passed to sqlite3_free_table() when
114** the calling procedure is finished using it.
115*/
116int sqlite3_get_table(
117 sqlite3 *db, /* The database on which the SQL executes */
118 const char *zSql, /* The SQL to be executed */
119 char ***pazResult, /* Write the result table here */
120 int *pnRow, /* Write the number of rows in the result here */
121 int *pnColumn, /* Write the number of columns of result here */
122 char **pzErrMsg /* Write error messages here */
123){
124 int rc;
125 TabResult res;
126
127#ifdef SQLITE_ENABLE_API_ARMOR
128 if( !sqlite3SafetyCheckOk(db) || pazResult==0 ) return SQLITE_MISUSE_BKPT;
129#endif
130 *pazResult = 0;
131 if( pnColumn ) *pnColumn = 0;
132 if( pnRow ) *pnRow = 0;
133 if( pzErrMsg ) *pzErrMsg = 0;
134 res.zErrMsg = 0;
135 res.nRow = 0;
136 res.nColumn = 0;
137 res.nData = 1;
138 res.nAlloc = 20;
139 res.rc = SQLITE_OK;
140 res.azResult = sqlite3_malloc64(sizeof(char*)*res.nAlloc );
141 if( res.azResult==0 ){
142 db->errCode = SQLITE_NOMEM;
143 return SQLITE_NOMEM_BKPT;
144 }
145 res.azResult[0] = 0;
146 rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);
147 assert( sizeof(res.azResult[0])>= sizeof(res.nData) );
148 res.azResult[0] = SQLITE_INT_TO_PTR(res.nData);
149 if( (rc&0xff)==SQLITE_ABORT ){
150 sqlite3_free_table(&res.azResult[1]);
151 if( res.zErrMsg ){
152 if( pzErrMsg ){
153 sqlite3_free(*pzErrMsg);
154 *pzErrMsg = sqlite3_mprintf("%s",res.zErrMsg);
155 }
156 sqlite3_free(res.zErrMsg);
157 }
158 db->errCode = res.rc; /* Assume 32-bit assignment is atomic */
159 return res.rc;
160 }
161 sqlite3_free(res.zErrMsg);
162 if( rc!=SQLITE_OK ){
163 sqlite3_free_table(&res.azResult[1]);
164 return rc;
165 }
166 if( res.nAlloc>res.nData ){
167 char **azNew;
168 azNew = sqlite3Realloc( res.azResult, sizeof(char*)*res.nData );
169 if( azNew==0 ){
170 sqlite3_free_table(&res.azResult[1]);
171 db->errCode = SQLITE_NOMEM;
172 return SQLITE_NOMEM_BKPT;
173 }
174 res.azResult = azNew;
175 }
176 *pazResult = &res.azResult[1];
177 if( pnColumn ) *pnColumn = res.nColumn;
178 if( pnRow ) *pnRow = res.nRow;
179 return rc;
180}
181
182/*
183** This routine frees the space the sqlite3_get_table() malloced.
184*/
185void sqlite3_free_table(
186 char **azResult /* Result returned from sqlite3_get_table() */
187){
188 if( azResult ){
189 int i, n;
190 azResult--;
191 assert( azResult!=0 );
192 n = SQLITE_PTR_TO_INT(azResult[0]);
193 for(i=1; i<n; i++){ if( azResult[i] ) sqlite3_free(azResult[i]); }
194 sqlite3_free(azResult);
195 }
196}
197
198#endif /* SQLITE_OMIT_GET_TABLE */
199