Tried "DROP TABLE / DROP TABLE IF EXISTS tablename" but got SQLITE_LOCKED, not SQLITE_DONE

Question

Tried "DROP TABLE / DROP TABLE IF EXISTS tablename" but got SQLITE_LOCKED, not SQLITE_DONE

I am developing an application for the iPhone that uses the sqlite library directly instead of CoreData. I tried to reset the table, but no matter how I tried, I always had SQLITE_LOCKEDinstead SQLITE_DONE.

I searched stackoverflow.com but could not find any similar problems. Here is my code:

`-DropTable:`

- (BOOL) dropTable: (NSString *) tableName {
    NSString * queryBase = [NSString stringWithFormat: @ "drop table if exists% @;", tableName];

    const char * query = [queryBase UTF8String];

    sqlite3_stmt * stmt = nil;

    if (sqlite3_prepare_v2 ([SLDBAccess sharedSLDBAccess] .database, query, -1, & stmt, NULL)! = SQLITE_OK) {
        NSAssert1 (0, @ "Error: failed to prepare statement with message '% s'.", Sqlite3_errmsg ([SLDBAccess sharedSLDBAccess] .database));
    }

    // transaction start
    sqlite3_exec ([SLDBAccess sharedSLDBAccess] .database, "BEGIN;", NULL, NULL, NULL);

/ *
The following line returns SQLITE_LOCKED, which the value is 6.
* /
    int dropOperationResult = sqlite3_step (stmt);
    sqlite3_reset (stmt);
    sqlite3_finalize (stmt);

    BOOL operationSucceeded = NO;
    if (dropOperationResult == SQLITE_DONE) {
        operationSucceeded = YES;
    }

    // transaction end
    if (operationSucceeded) {
        sqlite3_exec ([SLDBAccess sharedSLDBAccess] .database, "COMMIT;", NULL, NULL, NULL);
    } else {
        sqlite3_exec ([SLDBAccess sharedSLDBAccess] .database, "ROLLBACK;", NULL, NULL, NULL);
    }

    // No means failed.
    return operationSucceeded;
}

`-initTable:`

- (BOOL) initTimelineTableWith: (NSString *) tableName {
    NSString * queryBase = [NSString stringWithFormat: @ "CREATE TABLE% @ (id INTEGER PRIMARY KEY AUTOINCREMENT, timeline_id BIGINT UNSIGNED UNIQUE, in_reply_to_screen_name TEXT, in_reply_to_status_id INTEGER UNSIGNED, in_reply_to_user_id BIGINT UNSIGNED, source TEXT, text TEXT, favorited BOOLEAN, truncated BOOLEAN, retweeted_status BIGINT UNSIGNED, retweeted BOOLEAN, user BIGINT UNSIGNED, status INTEGER UNSIGNED, create_at DATETIME, update_on DATETIME); ", tableName];

    const char * query = [queryBase UTF8String];

    sqlite3_stmt * stmt = nil;

    if (sqlite3_prepare_v2 ([SLDBAccess sharedSLDBAccess] .database, query, -1, & stmt, NULL)! = SQLITE_OK) {
        NSAssert1(0, @"Error: failed to prepare statement with message '%s'.", sqlite3_errmsg([SLDBAccess sharedSLDBAccess].database));
    }

    //transaction start
    sqlite3_exec([SLDBAccess sharedSLDBAccess].database, "BEGIN;", NULL, NULL, NULL);

    int createOperationResult = sqlite3_step(stmt);
    sqlite3_reset(stmt);
    sqlite3_finalize(stmt);

    BOOL operationSucceeded = NO;
    if(createOperationResult == SQLITE_DONE) {
        operationSucceeded = YES;
    }

    //transaction end
    if (operationSucceeded) {
        sqlite3_exec([SLDBAccess sharedSLDBAccess].database, "COMMIT;", NULL, NULL, NULL);
        SLLog(@"create table successfully!");
    }else {
        sqlite3_exec([SLDBAccess sharedSLDBAccess].database, "ROLLBACK;", NULL, NULL, NULL);
        SLLog(@"create table failed!");
    }

    // No means failed.
    return operationSucceeded;
}

    NSString *newTableName = @"tonny_test";

    STAssertFalse([[DTModelHelper sharedDTModelHelper] isTableExistWith:newTableName], @"new table should not exsit.");
    STAssertTrue([[DTModelHelper sharedDTModelHelper] initTimelineTableWith:newTableName], @"init with new table.");
    STAssertTrue([[DTModelHelper sharedDTModelHelper] isTableExistWith:newTableName], @"new table should exsit after we created it.");

/*
The following 2 test cases always failed.
*/

    STAssertTrue([[DTModelHelper sharedDTModelHelper] dropTable:newTableName], @"drop table operation should return OK.");
    STAssertFalse([[DTModelHelper sharedDTModelHelper] isTableExistWith:newTableName], @"new table should not exsit after being dropped.");