Question

Ok, so I’m getting better with SQLite queries … but obviously not a master yet.

I am trying to loop through the array this returns, and all I am getting is 0 for every entry.

Here is what is making the query call and returning the result (this particular query should currently return 6 lines of data):

-(NSMutableArray *)getMyAthleteList
{
NSMutableArray *athleteList = [[NSMutableArray alloc] init];

NSString *getAthleteListSQL = [[NSString alloc] initWithFormat:@"SELECT * FROM athletes"];

sqlite3_stmt *selectStmt;

if (sqlite3_prepare_v2(database, [getAthleteListSQL UTF8String], -1, &selectStmt, nil)==SQLITE_OK)
{
    while (sqlite3_step(selectStmt)==SQLITE_ROW)
    {
        //NSLog(@"Adding athletes to the array");
        Athletes *athlete_array = [Athletes alloc];
        athlete_array.athlete_image = [[NSString alloc] initWithFormat:@"%d",sqlite3_column_int(selectStmt, 0)];
        athlete_array.athlete_id = [[NSString alloc] initWithFormat:@"%d",sqlite3_column_int(selectStmt, 1)];
        athlete_array.athlete_name = [[NSString alloc] initWithFormat:@"%d",sqlite3_column_int(selectStmt, 2)];
        athlete_array.school_name = [[NSString alloc] initWithFormat:@"%d",sqlite3_column_int(selectStmt, 3)];
        athlete_array.sport_name = [[NSString alloc] initWithFormat:@"%d",sqlite3_column_int(selectStmt, 4)];
        athlete_array.athlete_flag = [[NSString alloc] initWithFormat:@"%d",sqlite3_column_int(selectStmt, 5)];
        [athleteList addObject:athlete_array];
    }
}
else
{
    NSLog(@"Did not make a good query");
}

return athleteList;
}

Now here is what I am doing when calling and looping through it:

AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];

NSArray *myAthleteList = [[NSArray alloc] initWithArray:[appDelegate getMyAthleteList]];

for (Athletes *athlete in myAthleteList) {
    NSLog(@"Athlete Name: %@", athlete.athlete_name);
    NSLog(@"Athlete ID: %@", athlete.athlete_id);
}

And the output is:

Athlete Name: 0
Athlete ID: 0

My strings (athlete_name, athlete_id, etc.) are all defined correctly (in my Athletes.m and .h files).

I’m sure I’m missing something simple, but any help would be highly appreciated.

Thanks!

Answer 1

Are you expecting lines like this to return a string from the DB?

athlete_array.athlete_name = [[NSString alloc] initWithFormat:@"%d",
                              sqlite3_column_int(selectStmt, 2)];

If so, you might want to look into sqlite3_column_text or text16

See: http://www.sqlite.org/capi3ref.html#sqlite3_column_blob

You also may want to use this since it returns a const char *:

[[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(...)

For example, here’s a similar snippet from one of my samples:

contact = [[Contact alloc] init];
while (sqlite3_step(statement) == SQLITE_ROW)
{
    int idx = 0;

    NSNumber *idField = [NSNumber numberWithLongLong:sqlite3_column_int64(statement, idx++)];
    [contact setId:idField];

    NSString *nameField = [[NSString alloc] initWithUTF8String:
                           (const char *) sqlite3_column_text(statement, idx++)];
    [contact setName:nameField];

    NSString *addressField = [[NSString alloc] initWithUTF8String:
                            (const char *) sqlite3_column_text(statement, idx++)];
    [contact setAddress:addressField];

    NSString *phoneField = [[NSString alloc] initWithUTF8String:
                            (const char *) sqlite3_column_text(statement, idx)];
    [contact setPhone:phoneField];

    NSLog(@"id: %@", [contact id]);
    NSLog(@"name: %@", [contact name]);            
    NSLog(@"address: %@", [contact address]);
    NSLog(@"phone: %@", [contact phone]);

    // Code to do something with extracted data here

    [nameField release];
    [phoneField release];
    [addressField release];
}

Also, look into saving off your compiled statement &selectStmt and calling sqlite3_reset to use again. It’s compiled into byte code at that point and you don’t need to parse and compile your sql statement over and over.

See: http://www.sqlite.org/capi3ref.html#sqlite3_prepare

When you’re done with the statement (completely if you save it off), don’t forget to call sqlite3_finalize.