Question

I have an iPad app that is using a sqlite database using FMDB as a wrapper. I am able to successfully query data from the database; however when I attempt to insert data using executeUpdate, the method fires correctly (i.e. I get no errors and it returns YES) but nothing is actually inserted into the database. I try to immediately retrieve the object I just inserted and it is null. I also try to look at the number of rows in the table I inserted to and the table is empty. Any idea what I’m doing wrong? Here’s some of the code:

–init method of the class that handles all my db work

    -(NSString *)getDbPath {    
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,     NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];
        return [documentsDirectory stringByAppendingPathComponent:@"iRecipeBox.db"];
     }

    -(id)init {
        self = [super init];
        if(self) {
           database = [FMDatabase databaseWithPath:[self getDbPath]];
           [database open];
        }

       return self;
     }

–App delegate code that moves my db into the docs directory

    - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
    {
        // Override point for customization after application launch.
        NSFileManager *fileManager = [NSFileManager defaultManager];
        NSError *error;
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];

        NSString *docsPath = [documentsDirectory stringByAppendingPathComponent:@"iRecipeBox.db"];

        if ([fileManager fileExistsAtPath:docsPath] == NO) {
            NSString *resourcePath = [[NSBundle mainBundle] pathForResource:@"iRecipeBox" ofType:@"db"];
            [fileManager copyItemAtPath:resourcePath toPath:docsPath error:&error];
         }
         return YES;

}

–Code to insert data into one of the tables

    recipeID = [NSNumber numberWithInt:newRecipeID];
    [database beginTransaction];
    NSArray *newRow = [[NSArray alloc] initWithObjects:recipeID,title, description, picFile, prepTime, cookTime, ovenTemp, nil];
    NSString *sql = @"insert into recipes (id, name, descr, picFile, prepTime, cookTime, ovenTemp) values (?, ?, ?, ?, ?, ?, ?)";
    NSLog(@"Before update, the number of args is %i", [newRow count]);

    if([database executeUpdate:sql withArgumentsInArray:newRow]) {
        [database commit];
        NSLog(@"the insert worked");
    } else {
        [database rollback];
        NSLog(@"the insert failed");
    }

Answer 1

[FMDatabase databaseWithPath:] returns an autoreleased object, so you’re going to want to retain that if you’re not using ARC.

Check [database lastError] right after the executeUpdate:, and see if it says anything.

And finally- there’s no point in using a transaction if it’s just a single insert.