Reading from SQL database into NSArray - sql

Question

I have an iPad that reads data from an SQL database. The following code works fine and retrieves 2 fields from each record and reads them into an NSArray.
I now need to read 5 of the fields and I can't help but think that there is a better way of doing it rather than running 5 separate queries through php (the getinfo.php file with the choice parameter set to pick the different fields).
Any pointers to a better method for doing this?
NSString *strURLClass = [NSString stringWithFormat:#"%#%#", #"http://wwwaddress/getinfo.php?choice=1&schoolname=",obsSchoolName];
NSArray *observationsArrayClass = [[NSMutableArray alloc] initWithContentsOfURL:[NSURL URLWithString:strURLClass]];
observationListFromSQL = [[NSMutableArray alloc]init];
NSEnumerator *enumForObsClass = [observationsArrayClass objectEnumerator];
NSString *strURLDate = [NSString stringWithFormat:#"%#%#", #"http://wwwaddress/getinfo.php?choice=5&schoolname=",obsSchoolName];
NSArray *observationsArrayDate = [[NSMutableArray alloc] initWithContentsOfURL:[NSURL URLWithString:strURLDate]];
observationListFromSQL = [[NSMutableArray alloc]init];
NSEnumerator *enumForObsDate = [observationsArrayDate objectEnumerator];
id className, dateOfObs;
while (className = [enumForObsClass nextObject])
{
dateOfObs = [enumForObsDate nextObject];
[observationListFromSQL addObject:[NSDictionary dictionaryWithObjectsAndKeys:className, #"obsClass", dateOfObs, #"obsDate",nil]];
}

Answer 1

Yes, you can do that with less code by "folding" the statements into a loop, and using a mutable dictionary:
// Add other items that you wish to retrieve to the two arrays below:
NSArray *keys = #[#"obsClass", #"obsDate"]; // Key in the dictionary
NSArray *choices = #[#1, #5]; // Choice in the URL string
NSMutableArray *res = [NSMutableArray array];
NSMutableArray *observationListFromSQL = [NSMutableArray array];
for (int i = 0 ; i != keys.count ; i++) {
NSNumber *choice = choices[i];
NSString *strURLClass = [NSString stringWithFormat:#"http://wwwaddress/getinfo.php?choice=%#&schoolname=%#", choice, obsSchoolName];
NSArray *observationsArray = [[NSMutableArray alloc] initWithContentsOfURL:[NSURL URLWithString:strURLClass]];
NSEnumerator *objEnum = [observationsArrayClass objectEnumerator];
NSString *key = keys[i];
NSMutableDictionary *dict;
if (res.count < i) {
dict = res[i];
} else {
dict = [NSMutableDictionary dictionary];
[res addObject:dict];
}
id item;
while (item = [objEnum nextObject]) {
[res setObject:item forKey:key];
}
}