Question

I’m getting my data ,with several similar methods, from sqlite3 file like in following code:

-(NSMutableArray *) getCountersByID:(NSString *) championID{

    NSMutableArray *arrayOfCounters;
    arrayOfCounters = [[NSMutableArray alloc] init];

    @try {
        NSFileManager *fileManager = [NSFileManager defaultManager];
        NSString *databasePath = [[[NSBundle mainBundle] resourcePath ]stringByAppendingPathComponent:@"DatabaseCounters.sqlite"];
        BOOL success = [fileManager fileExistsAtPath:databasePath];

        if (!success) {
            NSLog(@"cannot connect to Database! at filepath %@",databasePath);
        }
        else{
            NSLog (@"SUCCESS getCountersByID!!");
        }
        if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK){

            NSString *tempString = [NSString stringWithFormat:@"SELECT COUNTER_ID FROM COUNTERS WHERE CHAMPION_ID = %@",championID];
            const char *sql = [tempString cStringUsingEncoding:NSASCIIStringEncoding];
            sqlite3_stmt *sqlStatement;

            int ret = sqlite3_prepare(database, sql, -1, &sqlStatement, NULL);

            if (ret != SQLITE_OK) {
                NSLog(@"Error calling sqlite3_prepare: %d", ret);
            }
            if(sqlite3_prepare_v2(database, sql, -1, &sqlStatement, NULL) == SQLITE_OK){

                while (sqlite3_step(sqlStatement)==SQLITE_ROW) {
                    counterList *CounterList = [[counterList alloc]init];
                    CounterList.counterID = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,0)];
                    [arrayOfCounters addObject:CounterList];
                }
            }
            else{
                NSLog(@"problem with database prepare");
            }
            sqlite3_finalize(sqlStatement);
        }
        else{
            NSLog(@"problem with database openning %s",sqlite3_errmsg(database));
        }   
    }
    @catch (NSException *exception){
        NSLog(@"An exception occured: %@", [exception reason]);
    }
    @finally{
        sqlite3_close(database);
        return arrayOfCounters;
    }
    //end
}

then i’m getting access to data with this and other similar lines of code:

myCounterList *MyCounterList = [[myCounterList alloc] init];
countersTempArray = [MyCounterList getCountersByID:"2"];

[countersArray addObject:[NSString stringWithFormat:@"%@",(((counterList *) [countersTempArray objectAtIndex:i]).counterID)]];

I’m getting a lot of data like image name and showing combination of them that depends on users input with such code:

UIImage *tempImage = [UIImage imageNamed:[NSString stringWithFormat:@"%@_0.jpg",[countersArray objectAtIndex:0]]];

[championSelection setBackgroundImage:tempImage forState:UIControlStateNormal];

---

My problem:

When i’m run my app for some time and get a lot of data it throws error: ” problem with database openning unable to open database file – error = 24 (Too many open files)“

My guess is that i’m opening my database every time when getCountersByID is called but not closing it.

My question:

Am i using right approach to open and close database that i use?

---

Similar questions that did not helped me to solve this problem:

1. unable to open database
2. Sqlite Opening Error : Unable to open database

---

UPDATE:

I made assumption that error is showing up because i use this lines of code too much:

NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *databasePath = [[[NSBundle mainBundle] resourcePath ]stringByAppendingPathComponent:@"DatabaseCounters.sqlite"];
BOOL success = [fileManager fileExistsAtPath:databasePath];

and ending up with error 24.

So i made them global but sqlite3_errmsg shows same err 24, but app runs much faster now

Answer 1

You should open your DB only once basically when you are in the initialization phase but not when you are requesting some info to your DB. Your code shouldn’t failed though since you seems to open then close the DB after each request. Make sure this is happening by either logging those events or debugging through your code.