1 /* 2 ** 2006 June 10 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 ** Code for testing the virtual table interfaces. This code 13 ** is not included in the SQLite library. It is used for automated 14 ** testing of the SQLite library. 15 */ 16 17 /* The code in this file defines a sqlite3 virtual-table module that 18 ** provides a read-only view of the current database schema. There is one 19 ** row in the schema table for each column in the database schema. 20 */ 21 #define SCHEMA \ 22 "CREATE TABLE x(" \ 23 "database," /* Name of database (i.e. main, temp etc.) */ \ 24 "tablename," /* Name of table */ \ 25 "cid," /* Column number (from left-to-right, 0 upward) */ \ 26 "name," /* Column name */ \ 27 "type," /* Specified type (i.e. VARCHAR(32)) */ \ 28 "not_null," /* Boolean. True if NOT NULL was specified */ \ 29 "dflt_value," /* Default value for this column */ \ 30 "pk" /* True if this column is part of the primary key */ \ 31 ")" 32 33 /* If SQLITE_TEST is defined this code is preprocessed for use as part 34 ** of the sqlite test binary "testfixture". Otherwise it is preprocessed 35 ** to be compiled into an sqlite dynamic extension. 36 */ 37 #ifdef SQLITE_TEST 38 # include "sqliteInt.h" 39 # if defined(INCLUDE_SQLITE_TCL_H) 40 # include "sqlite_tcl.h" 41 # else 42 # include "tcl.h" 43 # endif 44 #else 45 # include "sqlite3ext.h" 46 SQLITE_EXTENSION_INIT1 47 #endif 48 49 #include <stdlib.h> 50 #include <string.h> 51 #include <assert.h> 52 53 typedef struct schema_vtab schema_vtab; 54 typedef struct schema_cursor schema_cursor; 55 56 /* A schema table object */ 57 struct schema_vtab { 58 sqlite3_vtab base; 59 sqlite3 *db; 60 }; 61 62 /* A schema table cursor object */ 63 struct schema_cursor { 64 sqlite3_vtab_cursor base; 65 sqlite3_stmt *pDbList; 66 sqlite3_stmt *pTableList; 67 sqlite3_stmt *pColumnList; 68 int rowid; 69 }; 70 71 /* 72 ** None of this works unless we have virtual tables. 73 */ 74 #ifndef SQLITE_OMIT_VIRTUALTABLE 75 76 /* 77 ** Table destructor for the schema module. 78 */ 79 static int schemaDestroy(sqlite3_vtab *pVtab){ 80 sqlite3_free(pVtab); 81 return 0; 82 } 83 84 /* 85 ** Table constructor for the schema module. 86 */ 87 static int schemaCreate( 88 sqlite3 *db, 89 void *pAux, 90 int argc, const char *const*argv, 91 sqlite3_vtab **ppVtab, 92 char **pzErr 93 ){ 94 int rc = SQLITE_NOMEM; 95 schema_vtab *pVtab = sqlite3_malloc(sizeof(schema_vtab)); 96 if( pVtab ){ 97 memset(pVtab, 0, sizeof(schema_vtab)); 98 pVtab->db = db; 99 #ifndef SQLITE_OMIT_VIRTUALTABLE 100 rc = sqlite3_declare_vtab(db, SCHEMA); 101 #endif 102 } 103 *ppVtab = (sqlite3_vtab *)pVtab; 104 return rc; 105 } 106 107 /* 108 ** Open a new cursor on the schema table. 109 */ 110 static int schemaOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){ 111 int rc = SQLITE_NOMEM; 112 schema_cursor *pCur; 113 pCur = sqlite3_malloc(sizeof(schema_cursor)); 114 if( pCur ){ 115 memset(pCur, 0, sizeof(schema_cursor)); 116 *ppCursor = (sqlite3_vtab_cursor *)pCur; 117 rc = SQLITE_OK; 118 } 119 return rc; 120 } 121 122 /* 123 ** Close a schema table cursor. 124 */ 125 static int schemaClose(sqlite3_vtab_cursor *cur){ 126 schema_cursor *pCur = (schema_cursor *)cur; 127 sqlite3_finalize(pCur->pDbList); 128 sqlite3_finalize(pCur->pTableList); 129 sqlite3_finalize(pCur->pColumnList); 130 sqlite3_free(pCur); 131 return SQLITE_OK; 132 } 133 134 /* 135 ** Retrieve a column of data. 136 */ 137 static int schemaColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){ 138 schema_cursor *pCur = (schema_cursor *)cur; 139 switch( i ){ 140 case 0: 141 sqlite3_result_value(ctx, sqlite3_column_value(pCur->pDbList, 1)); 142 break; 143 case 1: 144 sqlite3_result_value(ctx, sqlite3_column_value(pCur->pTableList, 0)); 145 break; 146 default: 147 sqlite3_result_value(ctx, sqlite3_column_value(pCur->pColumnList, i-2)); 148 break; 149 } 150 return SQLITE_OK; 151 } 152 153 /* 154 ** Retrieve the current rowid. 155 */ 156 static int schemaRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ 157 schema_cursor *pCur = (schema_cursor *)cur; 158 *pRowid = pCur->rowid; 159 return SQLITE_OK; 160 } 161 162 static int finalize(sqlite3_stmt **ppStmt){ 163 int rc = sqlite3_finalize(*ppStmt); 164 *ppStmt = 0; 165 return rc; 166 } 167 168 static int schemaEof(sqlite3_vtab_cursor *cur){ 169 schema_cursor *pCur = (schema_cursor *)cur; 170 return (pCur->pDbList ? 0 : 1); 171 } 172 173 /* 174 ** Advance the cursor to the next row. 175 */ 176 static int schemaNext(sqlite3_vtab_cursor *cur){ 177 int rc = SQLITE_OK; 178 schema_cursor *pCur = (schema_cursor *)cur; 179 schema_vtab *pVtab = (schema_vtab *)(cur->pVtab); 180 char *zSql = 0; 181 182 while( !pCur->pColumnList || SQLITE_ROW!=sqlite3_step(pCur->pColumnList) ){ 183 if( SQLITE_OK!=(rc = finalize(&pCur->pColumnList)) ) goto next_exit; 184 185 while( !pCur->pTableList || SQLITE_ROW!=sqlite3_step(pCur->pTableList) ){ 186 if( SQLITE_OK!=(rc = finalize(&pCur->pTableList)) ) goto next_exit; 187 188 assert(pCur->pDbList); 189 while( SQLITE_ROW!=sqlite3_step(pCur->pDbList) ){ 190 rc = finalize(&pCur->pDbList); 191 goto next_exit; 192 } 193 194 /* Set zSql to the SQL to pull the list of tables from the 195 ** sqlite_schema (or sqlite_temp_schema) table of the database 196 ** identified by the row pointed to by the SQL statement pCur->pDbList 197 ** (iterating through a "PRAGMA database_list;" statement). 198 */ 199 if( sqlite3_column_int(pCur->pDbList, 0)==1 ){ 200 zSql = sqlite3_mprintf( 201 "SELECT name FROM sqlite_temp_schema WHERE type='table'" 202 ); 203 }else{ 204 sqlite3_stmt *pDbList = pCur->pDbList; 205 zSql = sqlite3_mprintf( 206 "SELECT name FROM %Q.sqlite_schema WHERE type='table'", 207 sqlite3_column_text(pDbList, 1) 208 ); 209 } 210 if( !zSql ){ 211 rc = SQLITE_NOMEM; 212 goto next_exit; 213 } 214 215 rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pTableList, 0); 216 sqlite3_free(zSql); 217 if( rc!=SQLITE_OK ) goto next_exit; 218 } 219 220 /* Set zSql to the SQL to the table_info pragma for the table currently 221 ** identified by the rows pointed to by statements pCur->pDbList and 222 ** pCur->pTableList. 223 */ 224 zSql = sqlite3_mprintf("PRAGMA %Q.table_info(%Q)", 225 sqlite3_column_text(pCur->pDbList, 1), 226 sqlite3_column_text(pCur->pTableList, 0) 227 ); 228 229 if( !zSql ){ 230 rc = SQLITE_NOMEM; 231 goto next_exit; 232 } 233 rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pColumnList, 0); 234 sqlite3_free(zSql); 235 if( rc!=SQLITE_OK ) goto next_exit; 236 } 237 pCur->rowid++; 238 239 next_exit: 240 /* TODO: Handle rc */ 241 return rc; 242 } 243 244 /* 245 ** Reset a schema table cursor. 246 */ 247 static int schemaFilter( 248 sqlite3_vtab_cursor *pVtabCursor, 249 int idxNum, const char *idxStr, 250 int argc, sqlite3_value **argv 251 ){ 252 int rc; 253 schema_vtab *pVtab = (schema_vtab *)(pVtabCursor->pVtab); 254 schema_cursor *pCur = (schema_cursor *)pVtabCursor; 255 pCur->rowid = 0; 256 finalize(&pCur->pTableList); 257 finalize(&pCur->pColumnList); 258 finalize(&pCur->pDbList); 259 rc = sqlite3_prepare(pVtab->db,"PRAGMA database_list", -1, &pCur->pDbList, 0); 260 return (rc==SQLITE_OK ? schemaNext(pVtabCursor) : rc); 261 } 262 263 /* 264 ** Analyse the WHERE condition. 265 */ 266 static int schemaBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ 267 return SQLITE_OK; 268 } 269 270 /* 271 ** A virtual table module that merely echos method calls into TCL 272 ** variables. 273 */ 274 static sqlite3_module schemaModule = { 275 0, /* iVersion */ 276 schemaCreate, 277 schemaCreate, 278 schemaBestIndex, 279 schemaDestroy, 280 schemaDestroy, 281 schemaOpen, /* xOpen - open a cursor */ 282 schemaClose, /* xClose - close a cursor */ 283 schemaFilter, /* xFilter - configure scan constraints */ 284 schemaNext, /* xNext - advance a cursor */ 285 schemaEof, /* xEof */ 286 schemaColumn, /* xColumn - read data */ 287 schemaRowid, /* xRowid - read data */ 288 0, /* xUpdate */ 289 0, /* xBegin */ 290 0, /* xSync */ 291 0, /* xCommit */ 292 0, /* xRollback */ 293 0, /* xFindMethod */ 294 0, /* xRename */ 295 }; 296 297 #endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */ 298 299 #ifdef SQLITE_TEST 300 301 /* 302 ** Decode a pointer to an sqlite3 object. 303 */ 304 extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb); 305 306 /* 307 ** Register the schema virtual table module. 308 */ 309 static int SQLITE_TCLAPI register_schema_module( 310 ClientData clientData, /* Not used */ 311 Tcl_Interp *interp, /* The TCL interpreter that invoked this command */ 312 int objc, /* Number of arguments */ 313 Tcl_Obj *CONST objv[] /* Command arguments */ 314 ){ 315 sqlite3 *db; 316 if( objc!=2 ){ 317 Tcl_WrongNumArgs(interp, 1, objv, "DB"); 318 return TCL_ERROR; 319 } 320 if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR; 321 #ifndef SQLITE_OMIT_VIRTUALTABLE 322 sqlite3_create_module(db, "schema", &schemaModule, 0); 323 #endif 324 return TCL_OK; 325 } 326 327 /* 328 ** Register commands with the TCL interpreter. 329 */ 330 int Sqlitetestschema_Init(Tcl_Interp *interp){ 331 static struct { 332 char *zName; 333 Tcl_ObjCmdProc *xProc; 334 void *clientData; 335 } aObjCmd[] = { 336 { "register_schema_module", register_schema_module, 0 }, 337 }; 338 int i; 339 for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){ 340 Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 341 aObjCmd[i].xProc, aObjCmd[i].clientData, 0); 342 } 343 return TCL_OK; 344 } 345 346 #else 347 348 /* 349 ** Extension load function. 350 */ 351 #ifdef _WIN32 352 __declspec(dllexport) 353 #endif 354 int sqlite3_schema_init( 355 sqlite3 *db, 356 char **pzErrMsg, 357 const sqlite3_api_routines *pApi 358 ){ 359 SQLITE_EXTENSION_INIT2(pApi); 360 #ifndef SQLITE_OMIT_VIRTUALTABLE 361 sqlite3_create_module(db, "schema", &schemaModule, 0); 362 #endif 363 return 0; 364 } 365 366 #endif 367