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objective-ccore-datansfetchrequest

Fetching all data from an Entity and printing only displays the last record


I'm trying to fetch all of the data from a particular Core Data Entity and place each record into a string. However the following code only prints the LAST record that it accesses. What am I doing wrong?

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Order" inManagedObjectContext:managedObjectContext];

[fetchRequest setEntity:entity];
NSArray *fetchedObjects = [managedObjectContext executeFetchRequest:fetchRequest error:&error];


NSLog(@"=============================================");
NSLog(@"Generating Data To Be Sent");
for (NSManagedObjectContext * info in fetchedObjects) 

{

    NSLog(@"Client Name: %@", [info valueForKey:@"clientName"]);
    NSLog(@"Client Account Number: %@", [info valueForKey:@"clientAccountNumber"]); 
    NSLog(@"Product Code: %@", [info valueForKey:@"productCode"]);
    NSLog(@"Product Price: %@", [info valueForKey:@"productPrice"]);
    NSLog(@"Product Quantity: %@", [info valueForKey:@"productQuantity"]);
    NSLog(@"Order Total: %@", [info valueForKey:@"orderTotal"]);
    NSLog(@"Order ID : %@", [info valueForKey:@"orderID"]); 
    NSLog(@"Transaction ID: %@", [info valueForKey:@"transactionID"]);
    NSLog(@"Sales Rep ID : %@", [info valueForKey:@"salesRepresentativeID"]);

}

NSString * printedData;
NSString * formattedData;

NSString * clientName;
NSString * clientAccount;
NSString * productCode;
NSString * productQuantity;
NSString * productPrice;
NSString * orderTotal;
NSString * orderID;
NSString * transactionID;
NSString * salesRepID;



for(NSManagedObject * info in fetchedObjects)

{

    clientName = [info valueForKey:@"clientName"];
    clientAccount =  [info valueForKey:@"clientAccountNumber"]; 
    productCode =  [info valueForKey:@"productCode"];
    productPrice =  [info valueForKey:@"productPrice"];
    productQuantity = [info valueForKey:@"productQuantity"];
    orderTotal =  [info valueForKey:@"orderTotal"];
    orderID = [info valueForKey:@"orderID"]; 
    transactionID = [info valueForKey:@"transactionID"];
    salesRepID = [info valueForKey:@"salesRepresentativeID"];


    formattedData = [NSString stringWithFormat:@"|%@|%@|%@|%@|%@|%@|%@|%@|%@|\n",clientName,clientAccount,productCode,productQuantity,productPrice,orderID,transactionID,orderTotal,salesRepID];

    printedData = formattedData;

}

NSLog(@"=============================================");
NSLog(@"Data Generated");
NSLog(@"%@",printedData);
[fetchRequest release];

NSMutableArray *recipients = [[NSMutableArray alloc] initWithCapacity:1];
[recipients addObject:toEmail.text];

MFMailComposeViewController *controller = [[MFMailComposeViewController alloc] init];
controller.mailComposeDelegate = self;
[controller setSubject:toSubject.text];
[controller setMessageBody:printedData isHTML:NO];
[controller setToRecipients:recipients];

[self presentModalViewController:controller animated:YES];
[controller release];

Solution

  • To fix your initial problem you need to use an NSMutableString. There is no need for formattedData variable.

    ...
    NSMutableString * printedData = [NSMutableString string];
    ...
    
    for(NSManagedObject * info in fetchedObjects)
    {
        ...
        [printedData appendFormat:@"|%@|%@|%@|%@|%@|%@|%@|%@|%@|\n",clientName,clientAccount,productCode,productQuantity,productPrice,orderID,transactionID,orderTotal,salesRepID];
    }
    ...
    

    Your next issue is how inefficient this code is. You are looping over the same collection twice, once to log, once to create a formatted string. You can combine this into one loop. Also all of the variables are defined outside of the scope of the for loop that they are used in, you could simply just declare each one on a line like this.

    for(NSManagedObject * info in fetchedObjects)
    {
        NSString *clientName = [info valueForKey:@"clientName"];
        NSString *clientAccount =  [info valueForKey:@"clientAccountNumber"];
        ...
        //Log them all
        NSLog(@"%@",clientName);
        NSLog(@"%@",clientAccount);
        ...
    }