sl@0: /*
sl@0: ** 2006 June 10
sl@0: **
sl@0: ** The author disclaims copyright to this source code.  In place of
sl@0: ** a legal notice, here is a blessing:
sl@0: **
sl@0: **    May you do good and not evil.
sl@0: **    May you find forgiveness for yourself and forgive others.
sl@0: **    May you share freely, never taking more than you give.
sl@0: **
sl@0: *************************************************************************
sl@0: ** Code for testing the virtual table interfaces.  This code
sl@0: ** is not included in the SQLite library.  It is used for automated
sl@0: ** testing of the SQLite library.
sl@0: **
sl@0: ** $Id: test_schema.c,v 1.15 2008/07/07 14:50:14 drh Exp $
sl@0: */
sl@0: 
sl@0: /* The code in this file defines a sqlite3 virtual-table module that
sl@0: ** provides a read-only view of the current database schema. There is one
sl@0: ** row in the schema table for each column in the database schema.
sl@0: */
sl@0: #define SCHEMA \
sl@0: "CREATE TABLE x("                                                            \
sl@0:   "database,"          /* Name of database (i.e. main, temp etc.) */         \
sl@0:   "tablename,"         /* Name of table */                                   \
sl@0:   "cid,"               /* Column number (from left-to-right, 0 upward) */    \
sl@0:   "name,"              /* Column name */                                     \
sl@0:   "type,"              /* Specified type (i.e. VARCHAR(32)) */               \
sl@0:   "not_null,"          /* Boolean. True if NOT NULL was specified */         \
sl@0:   "dflt_value,"        /* Default value for this column */                   \
sl@0:   "pk"                 /* True if this column is part of the primary key */  \
sl@0: ")"
sl@0: 
sl@0: /* If SQLITE_TEST is defined this code is preprocessed for use as part
sl@0: ** of the sqlite test binary "testfixture". Otherwise it is preprocessed
sl@0: ** to be compiled into an sqlite dynamic extension.
sl@0: */
sl@0: #ifdef SQLITE_TEST
sl@0:   #include "sqliteInt.h"
sl@0:   #include "tcl.h"
sl@0: #else
sl@0:   #include "sqlite3ext.h"
sl@0:   SQLITE_EXTENSION_INIT1
sl@0: #endif
sl@0: 
sl@0: #include <stdlib.h>
sl@0: #include <string.h>
sl@0: #include <assert.h>
sl@0: 
sl@0: typedef struct schema_vtab schema_vtab;
sl@0: typedef struct schema_cursor schema_cursor;
sl@0: 
sl@0: /* A schema table object */
sl@0: struct schema_vtab {
sl@0:   sqlite3_vtab base;
sl@0:   sqlite3 *db;
sl@0: };
sl@0: 
sl@0: /* A schema table cursor object */
sl@0: struct schema_cursor {
sl@0:   sqlite3_vtab_cursor base;
sl@0:   sqlite3_stmt *pDbList;
sl@0:   sqlite3_stmt *pTableList;
sl@0:   sqlite3_stmt *pColumnList;
sl@0:   int rowid;
sl@0: };
sl@0: 
sl@0: /*
sl@0: ** None of this works unless we have virtual tables.
sl@0: */
sl@0: #ifndef SQLITE_OMIT_VIRTUALTABLE
sl@0: 
sl@0: /*
sl@0: ** Table destructor for the schema module.
sl@0: */
sl@0: static int schemaDestroy(sqlite3_vtab *pVtab){
sl@0:   sqlite3_free(pVtab);
sl@0:   return 0;
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** Table constructor for the schema module.
sl@0: */
sl@0: static int schemaCreate(
sl@0:   sqlite3 *db,
sl@0:   void *pAux,
sl@0:   int argc, const char *const*argv,
sl@0:   sqlite3_vtab **ppVtab,
sl@0:   char **pzErr
sl@0: ){
sl@0:   int rc = SQLITE_NOMEM;
sl@0:   schema_vtab *pVtab = sqlite3_malloc(sizeof(schema_vtab));
sl@0:   if( pVtab ){
sl@0:     memset(pVtab, 0, sizeof(schema_vtab));
sl@0:     pVtab->db = db;
sl@0: #ifndef SQLITE_OMIT_VIRTUALTABLE
sl@0:     rc = sqlite3_declare_vtab(db, SCHEMA);
sl@0: #endif
sl@0:   }
sl@0:   *ppVtab = (sqlite3_vtab *)pVtab;
sl@0:   return rc;
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** Open a new cursor on the schema table.
sl@0: */
sl@0: static int schemaOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
sl@0:   int rc = SQLITE_NOMEM;
sl@0:   schema_cursor *pCur;
sl@0:   pCur = sqlite3_malloc(sizeof(schema_cursor));
sl@0:   if( pCur ){
sl@0:     memset(pCur, 0, sizeof(schema_cursor));
sl@0:     *ppCursor = (sqlite3_vtab_cursor *)pCur;
sl@0:     rc = SQLITE_OK;
sl@0:   }
sl@0:   return rc;
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** Close a schema table cursor.
sl@0: */
sl@0: static int schemaClose(sqlite3_vtab_cursor *cur){
sl@0:   schema_cursor *pCur = (schema_cursor *)cur;
sl@0:   sqlite3_finalize(pCur->pDbList);
sl@0:   sqlite3_finalize(pCur->pTableList);
sl@0:   sqlite3_finalize(pCur->pColumnList);
sl@0:   sqlite3_free(pCur);
sl@0:   return SQLITE_OK;
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** Retrieve a column of data.
sl@0: */
sl@0: static int schemaColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
sl@0:   schema_cursor *pCur = (schema_cursor *)cur;
sl@0:   switch( i ){
sl@0:     case 0:
sl@0:       sqlite3_result_value(ctx, sqlite3_column_value(pCur->pDbList, 1));
sl@0:       break;
sl@0:     case 1:
sl@0:       sqlite3_result_value(ctx, sqlite3_column_value(pCur->pTableList, 0));
sl@0:       break;
sl@0:     default:
sl@0:       sqlite3_result_value(ctx, sqlite3_column_value(pCur->pColumnList, i-2));
sl@0:       break;
sl@0:   }
sl@0:   return SQLITE_OK;
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** Retrieve the current rowid.
sl@0: */
sl@0: static int schemaRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
sl@0:   schema_cursor *pCur = (schema_cursor *)cur;
sl@0:   *pRowid = pCur->rowid;
sl@0:   return SQLITE_OK;
sl@0: }
sl@0: 
sl@0: static int finalize(sqlite3_stmt **ppStmt){
sl@0:   int rc = sqlite3_finalize(*ppStmt);
sl@0:   *ppStmt = 0;
sl@0:   return rc;
sl@0: }
sl@0: 
sl@0: static int schemaEof(sqlite3_vtab_cursor *cur){
sl@0:   schema_cursor *pCur = (schema_cursor *)cur;
sl@0:   return (pCur->pDbList ? 0 : 1);
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** Advance the cursor to the next row.
sl@0: */
sl@0: static int schemaNext(sqlite3_vtab_cursor *cur){
sl@0:   int rc = SQLITE_OK;
sl@0:   schema_cursor *pCur = (schema_cursor *)cur;
sl@0:   schema_vtab *pVtab = (schema_vtab *)(cur->pVtab);
sl@0:   char *zSql = 0;
sl@0: 
sl@0:   while( !pCur->pColumnList || SQLITE_ROW!=sqlite3_step(pCur->pColumnList) ){
sl@0:     if( SQLITE_OK!=(rc = finalize(&pCur->pColumnList)) ) goto next_exit;
sl@0: 
sl@0:     while( !pCur->pTableList || SQLITE_ROW!=sqlite3_step(pCur->pTableList) ){
sl@0:       if( SQLITE_OK!=(rc = finalize(&pCur->pTableList)) ) goto next_exit;
sl@0: 
sl@0:       assert(pCur->pDbList);
sl@0:       while( SQLITE_ROW!=sqlite3_step(pCur->pDbList) ){
sl@0:         rc = finalize(&pCur->pDbList);
sl@0:         goto next_exit;
sl@0:       }
sl@0: 
sl@0:       /* Set zSql to the SQL to pull the list of tables from the 
sl@0:       ** sqlite_master (or sqlite_temp_master) table of the database
sl@0:       ** identfied by the row pointed to by the SQL statement pCur->pDbList
sl@0:       ** (iterating through a "PRAGMA database_list;" statement).
sl@0:       */
sl@0:       if( sqlite3_column_int(pCur->pDbList, 0)==1 ){
sl@0:         zSql = sqlite3_mprintf(
sl@0:             "SELECT name FROM sqlite_temp_master WHERE type='table'"
sl@0:         );
sl@0:       }else{
sl@0:         sqlite3_stmt *pDbList = pCur->pDbList;
sl@0:         zSql = sqlite3_mprintf(
sl@0:             "SELECT name FROM %Q.sqlite_master WHERE type='table'",
sl@0:              sqlite3_column_text(pDbList, 1)
sl@0:         );
sl@0:       }
sl@0:       if( !zSql ){
sl@0:         rc = SQLITE_NOMEM;
sl@0:         goto next_exit;
sl@0:       }
sl@0: 
sl@0:       rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pTableList, 0);
sl@0:       sqlite3_free(zSql);
sl@0:       if( rc!=SQLITE_OK ) goto next_exit;
sl@0:     }
sl@0: 
sl@0:     /* Set zSql to the SQL to the table_info pragma for the table currently
sl@0:     ** identified by the rows pointed to by statements pCur->pDbList and
sl@0:     ** pCur->pTableList.
sl@0:     */
sl@0:     zSql = sqlite3_mprintf("PRAGMA %Q.table_info(%Q)", 
sl@0:         sqlite3_column_text(pCur->pDbList, 1),
sl@0:         sqlite3_column_text(pCur->pTableList, 0)
sl@0:     );
sl@0: 
sl@0:     if( !zSql ){
sl@0:       rc = SQLITE_NOMEM;
sl@0:       goto next_exit;
sl@0:     }
sl@0:     rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pColumnList, 0);
sl@0:     sqlite3_free(zSql);
sl@0:     if( rc!=SQLITE_OK ) goto next_exit;
sl@0:   }
sl@0:   pCur->rowid++;
sl@0: 
sl@0: next_exit:
sl@0:   /* TODO: Handle rc */
sl@0:   return rc;
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** Reset a schema table cursor.
sl@0: */
sl@0: static int schemaFilter(
sl@0:   sqlite3_vtab_cursor *pVtabCursor, 
sl@0:   int idxNum, const char *idxStr,
sl@0:   int argc, sqlite3_value **argv
sl@0: ){
sl@0:   int rc;
sl@0:   schema_vtab *pVtab = (schema_vtab *)(pVtabCursor->pVtab);
sl@0:   schema_cursor *pCur = (schema_cursor *)pVtabCursor;
sl@0:   pCur->rowid = 0;
sl@0:   finalize(&pCur->pTableList);
sl@0:   finalize(&pCur->pColumnList);
sl@0:   finalize(&pCur->pDbList);
sl@0:   rc = sqlite3_prepare(pVtab->db,"PRAGMA database_list", -1, &pCur->pDbList, 0);
sl@0:   return (rc==SQLITE_OK ? schemaNext(pVtabCursor) : rc);
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** Analyse the WHERE condition.
sl@0: */
sl@0: static int schemaBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
sl@0:   return SQLITE_OK;
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** A virtual table module that merely echos method calls into TCL
sl@0: ** variables.
sl@0: */
sl@0: static sqlite3_module schemaModule = {
sl@0:   0,                           /* iVersion */
sl@0:   schemaCreate,
sl@0:   schemaCreate,
sl@0:   schemaBestIndex,
sl@0:   schemaDestroy,
sl@0:   schemaDestroy,
sl@0:   schemaOpen,                  /* xOpen - open a cursor */
sl@0:   schemaClose,                 /* xClose - close a cursor */
sl@0:   schemaFilter,                /* xFilter - configure scan constraints */
sl@0:   schemaNext,                  /* xNext - advance a cursor */
sl@0:   schemaEof,                   /* xEof */
sl@0:   schemaColumn,                /* xColumn - read data */
sl@0:   schemaRowid,                 /* xRowid - read data */
sl@0:   0,                           /* xUpdate */
sl@0:   0,                           /* xBegin */
sl@0:   0,                           /* xSync */
sl@0:   0,                           /* xCommit */
sl@0:   0,                           /* xRollback */
sl@0:   0,                           /* xFindMethod */
sl@0:   0,                           /* xRename */
sl@0: };
sl@0: 
sl@0: #endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */
sl@0: 
sl@0: #ifdef SQLITE_TEST
sl@0: 
sl@0: /*
sl@0: ** Decode a pointer to an sqlite3 object.
sl@0: */
sl@0: extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
sl@0: 
sl@0: /*
sl@0: ** Register the schema virtual table module.
sl@0: */
sl@0: static int register_schema_module(
sl@0:   ClientData clientData, /* Not used */
sl@0:   Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
sl@0:   int objc,              /* Number of arguments */
sl@0:   Tcl_Obj *CONST objv[]  /* Command arguments */
sl@0: ){
sl@0:   sqlite3 *db;
sl@0:   if( objc!=2 ){
sl@0:     Tcl_WrongNumArgs(interp, 1, objv, "DB");
sl@0:     return TCL_ERROR;
sl@0:   }
sl@0:   if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
sl@0: #ifndef SQLITE_OMIT_VIRTUALTABLE
sl@0:   sqlite3_create_module(db, "schema", &schemaModule, 0);
sl@0: #endif
sl@0:   return TCL_OK;
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** Register commands with the TCL interpreter.
sl@0: */
sl@0: int Sqlitetestschema_Init(Tcl_Interp *interp){
sl@0:   static struct {
sl@0:      char *zName;
sl@0:      Tcl_ObjCmdProc *xProc;
sl@0:      void *clientData;
sl@0:   } aObjCmd[] = {
sl@0:      { "register_schema_module", register_schema_module, 0 },
sl@0:   };
sl@0:   int i;
sl@0:   for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
sl@0:     Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
sl@0:         aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
sl@0:   }
sl@0:   return TCL_OK;
sl@0: }
sl@0: 
sl@0: #else
sl@0: 
sl@0: /*
sl@0: ** Extension load function.
sl@0: */
sl@0: int sqlite3_extension_init(
sl@0:   sqlite3 *db, 
sl@0:   char **pzErrMsg, 
sl@0:   const sqlite3_api_routines *pApi
sl@0: ){
sl@0:   SQLITE_EXTENSION_INIT2(pApi);
sl@0: #ifndef SQLITE_OMIT_VIRTUALTABLE
sl@0:   sqlite3_create_module(db, "schema", &schemaModule, 0);
sl@0: #endif
sl@0:   return 0;
sl@0: }
sl@0: 
sl@0: #endif