Change Data of database

Question

I'm developing for iOS and I have a previous database really poorly constructed. Now there is already 140 sealed but in my update I make a new database but I can not delete the data... How can I change the data from database A to database B ? I use sqlite3 in xCode 5

Answer 1

Here is an example code altering a column in a database table:

- (void)alterDB {

    sqlite3_stmt *statement;
    sqlite3_stmt *selectStmt;

    const char *columnExists = "select callCount from lastCall";
    //Alter the table ONLY IF column we want doesn't exist
    if (sqlite3_prepare_v2(database, columnExists, -1, &selectStmt, NULL) != SQLITE_OK)
    {
        NSString *updateSQL = [NSString stringWithFormat:@"ALTER TABLE lastCall ADD COLUMN callCount INTEGER"];
        const char *update_stmt = [updateSQL UTF8String];
        sqlite3_prepare_v2(database, update_stmt, -1, &statement, NULL);

        if (sqlite3_step(statement) == SQLITE_DONE) {
            NSLog(@"DATABASE ALTERED");
        } else {
            NSLog(@"error altering database");
        }
    }

}

I hope this gives you an idea.