Create Generic Function For Database Selects - objective-c

Question

I'm developing an iPhone app. I've got a function that reads data from a sqlite database and puts the results into an array. Everything works fine. Here is part of the function that fills the array:
while(sqlite3_step(compiledStatement) == SQLITE_ROW) {
NSString *aVar1 = [NSString stringWithUTF8String(char*)sqlite3_column_text(compiledStatement, 0)];
NSString *aVar2 = [NSString stringWithUTF8String(char*)sqlite3_column_text(compiledStatement, 1)];
NSArray *anArray = [NSArray arrayWithObjects:aVar1,aVar2,nil];
[returnArray addObject:anArray]
[anArray release];
}
//return the array
I want to make this function more generic so that it takes a sql statement string as a parameter, and returns a mutablearray of arrays, no matter how many columns are in the result set.
Is there a way to do this? The solution doesn't have to include arrays -- could be any collection object. I'm just looking for a way to make the function re-usable for other queries to the same database.

Answer 1

Couldn't you just do something like:
int numCols = sqlite3_column_count(compiledStatement);
NSMutableArray *result = [NSMutableArray array];
while(sqlite3_step(compiledStatement) == SQLITE_ROW) {
NSMutableArray *array = [NSMutableArray array];
for (int i = 0; i < numCols; i++) {
[array addObject:
[NSString stringWithUTF8String:
(char *)sqlite3_column_text(compiledStatement, i)]];
}
[result addObject:array];
}

Answer 2

+(NSArray *)executeQueryAndReturnArray:(NSString *)query {
sqlite3_stmt *statement = nil;
const char *sql = [query UTF8String];
if (sqlite3_prepare_v2(database, sql, -1, &statement, NULL) != SQLITE_OK) {
NSLog(#"[SQLITE] Error when preparing query!");
} else {
NSMutableArray *result = [NSMutableArray array];
while (sqlite3_step(statement) == SQLITE_ROW) {
NSMutableArray *row = [NSMutableArray array];
for (int i = 0; i < sqlite3_column_count(statement); i++) {
int colType = sqlite3_column_type(statement, i);
id value;
if (colType == SQLITE_TEXT) {`enter code here`
const unsigned char *col = sqlite3_column_text(statement, i);
value = [NSString stringWithFormat:#"%s", col];
} else if (colType == SQLITE_INTEGER) {
int col = sqlite3_column_int(statement, i);
value = [NSNumber numberWithInt:col];
} else if (colType == SQLITE_FLOAT) {
double col = sqlite3_column_double(statement, i);
value = [NSNumber numberWithDouble:col];
} else if (colType == SQLITE_NULL) {
value = [NSNull null];
} else {
NSLog(#"[SQLITE] UNKNOWN DATATYPE");
}
[row addObject:value];
}
[result addObject:row];
}
return result;
}
return nil;
}