sql and UIPickerView - ios

Question

I need to develop a sql statement based on values picked on a UIPickerView. If you need a visual idea, here's a link to the screenshot (sorry not enough reputation to post pics yet) . I haven't been able to find any documentation on this and want to make sure I'm on the right track before I dig into it.
Each component (kTypeComponent, kDifficultyComponent, kDescriptionComponent) has three rows to select from (ex. kTypeComponent row1=bike, row2=run, row3=swim)
My thought would be that the sql statement would look something like this
sqlite3_stmt *pickerStatement;
//This would give back a string of the row selected (i.e bike, run, swim)
NSInteger getTypeSelected = [pickerView selectedRowInComponent:kTypeComponent];
NSString typeSQL = [rowOneItems objectAtIndex:getTypeSelected];
const char *pickerSQL = "SELECT description FROM workoutTbl WHERE (type = typeSQL) AND ...
Is this possible to do with a sql statement? I'm only familiar with basic SQL, so I'm not sure
Would the SQL statement go in the action (button) or where I set up my NSMutableArray and open the database? Should it go into a different class?
Edit - Solution
In case anyone comes around with the same problem, here is the solution to it
- (NSArray *)getWorkoutListwithType:(NSString *)workoutType withDifficulty:(NSString *)difficulty withLength:(NSString *)length {
NSMutableArray *workouts;
#try {
NSFileManager *fileMgr = [NSFileManager defaultManager];
NSString *dbPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"workoutList.sqlite"];
// NSLog(#"Db path is %#",dbPath);
BOOL success = [fileMgr fileExistsAtPath:dbPath];
if (!success){
NSLog(#"Cannot locate database file '%#'.", dbPath);
}
if (!(sqlite3_open([dbPath UTF8String], &db) == SQLITE_OK)) {
NSLog(#"error with message '%s'.", sqlite3_errmsg(db));
}
// only alloc/init the array if the SQL database opens properly
workouts = [[NSMutableArray alloc] init];
sqlite3_stmt *sqlStatement;
// add "%%" as a wildcard so the query will say "difficulty LIKE '>30%' and match >30 MINS, >30 HOURS, etc.
NSString *sqlString = [NSString stringWithFormat: #"SELECT description FROM workoutTbl WHERE type LIKE '%#%%' AND difficulty LIKE '%#%%' AND duration LIKE '%#%%'", workoutType, difficulty, length];
NSLog(#"query: %#", sqlString);
const char *sql = [sqlString UTF8String];
if (sqlite3_prepare(db, sql, -1, &sqlStatement, NULL) != SQLITE_OK) {
NSLog(#"%s Prepare failure '%s' (%1d)", __FUNCTION__, sqlite3_errmsg(db), sqlite3_errcode(db));
}
while (sqlite3_step(sqlStatement)==SQLITE_ROW) {
[workouts addObject:[NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,0)]];
}
sqlite3_finalize(sqlStatement);
}
#catch (NSException *exception) {
NSLog(#"An exception occured: %#", [exception reason]);
}
#finally {
sqlite3_close(db);
}
// Pass back an immutable copy of the array. if the array is nil, then the database never opened and there will be an error
return [workouts copy];
}

Answer 1

What do you mean by 'three rows to select'? Do you mean 'three fields (columns) to select'? If you want to specify field values, then a statement should like
NSString* sqlStatement = [NSString stringWithFormat:#"SELECT * FROM workoutTbl WHERE type = '%#' AND id = '%i'", typeSQL,idNumber];