Combine two tables to create a mailing list.

I have two MySQL databases on my server for my customers. One has customers who work for universities and one has customers who purchased from our website or made inquiries by phone or email. There is some overlap between the two and for the latest product announcement, I wanted to avoid sending duplicate emails. I usually use a php script to do my queries. If I am sending to just one group, the query is fairly straightforward.


$fname = "./MarketingExports/email.txt";

    $sql  = "(SELECT name, email FROM Universities ";
    $sql .= "WHERE email IS NOT NULL AND email != '' ";
    $sql .= "AND duplicate_email = 0 ";
    $sql .= "AND remove_email != 1) ";
    $result = $dbMKT->query($sql);
    $numRecords = mysqli_num_rows($result);

    echo "There are $numRecords records.";
    // Open the file to save the words
    $fp = fopen($fname, 'w');
    if (!$fp) {
        echo "Couldn’t open file.";

    } else {

        echo "Save to file $fname.<br />";
        for ($i = 0; $i < $numRecords; $i++) {
            $row = $result->fetch_array();
            $id = $row["id"];
            $company = trim($row["company"]);
            $name = trim($row["name"]);
            $email = trim($row["email"]);
            // Add to the email mail list
            $info = "\"$name\" <$email>";
            fwrite ($fp, "$info" . "\r");

However, if I want to combine the University list and the other customers list, I need to adjust the query a bit by using a UNION

  $sql  = "(SELECT name, email, company FROM Customers ";
  $sql .= "WHERE email IS NOT NULL AND email != '' ";
  $sql .= "AND duplicate_email = 0 ";
  $sql .= "AND remove_email != 1) ";
  $sql .= "UNION ";
  $sql .= "(SELECT,, Universities.title FROM Universities, Customers ";
  $sql .= "WHERE IS NOT NULL AND != '' ";
  $sql .= "AND Universities.duplicate_email = 0 ";
  $sql .= "AND Universities.remove_email != 1 ";
  $sql .= "AND != ";
  $sql .= "ORDER BY email ";

Two things to note. Name and email are the same in both tables. However, some of my customer records have the customer name as the company and a blank name field. The UNION won’t work if there are a different number of fields in the SELECT statement, so I include the title field for Universities just to make MySQL happy.

I can order by email because it is in both tables. Notice also that I had to tell the second part of the query which table to work on for the WHERE statement.

An example of using Enums

After I posted my deviceType code on Stackoverflow, one of the commenters suggested that I use enums. Now I know what they are because Apple uses them all the time but I didn’t know how useful they were. I did some research on enums and they are nice. They make the code a bit more readable, but mostly they allow the compiler to help you type and catch errors. Xcode will autocomplete your deviceType for you and will give you the error: Use of undeclared identifier if you try to use a value that isn’t defined. I suspect that they are slightly faster in comparisons since they use integers rather than strings. Also, you can use them directly in switch statements. Here’s the code rewritten as an enum. I prefixed the values with LF but you should use whatever is appropriate for your project.

This is in my header file

// Devices as of Fall 2014
typedef NS_ENUM(NSInteger, LFdeviceType) {

And this is in my .m file.

+ (NSInteger)deviceType {
    CGSize screenSize = [[UIScreen mainScreen] bounds].size;
    CGFloat deviceScale = [UIScreen mainScreen].scale;
    LFdeviceType device = LFDeviceTypePhoneClassic;

    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
        device = LFDeviceTypePhoneClassic; // Just in case it doesn't make it through the conditionals
        // Classic has a resolution of 480 × 320
        if( (screenSize.height == 480 || screenSize.width == 480) && deviceScale == 1.0f ) {
            device = LFDeviceTypePhoneClassic;
        // Retina has a resolution of 960 × 640
        } else if( (screenSize.height == 480 || screenSize.width == 480) && deviceScale == 2.0f ) {
            device = LFDeviceTypePhoneRetina3_5;
        // Retina 4" has a resolution of 1136 x 640
        } else if (screenSize.height == 568 || screenSize.width == 568 ) {
            device = LFDeviceTypePhoneRetina4;
        // iPhone 6 has a resolution of 1334 by 750
        } else if (screenSize.height == 667 || screenSize.width == 667 ) {
            device = LFDeviceTypePhone6;
        // iPhone 6 Plus has an actual size of 2208 × 1242 and resolution of 1920 by 1080
        // Reported size is 736 x 414
        } else if (screenSize.height == 736 || screenSize.width == 736 ) {
            device = LFDeviceTypePhone6Plus;

    } else if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
        device = LFDeviceTypePadClassic; // Just in case it doesn't make it through the conditionals
        if(deviceScale == 1.0f) {
            device = LFDeviceTypePadClassic;
        } else if (deviceScale == 2.0f) {
            device = LFDeviceTypePadRetina;
    //NSLog(@"The device is %@ scale is %f and the height is %f and width is %f", device, deviceScale, screenSize.height, screenSize.width);

    return device;

Call it like this:

if ( (   [Utilities deviceType] == LFDeviceTypePhoneClassic 
      || [Utilities deviceType] == LFDeviceTypePhoneRetina3_5) &&
        numberOfFoilsOnScreen > 7 ) {
        numberOfFoilsOnScreen = 7;

Update UIAlertView to UIAlertController

UIAlertView and UIActionSheet have been deprecated in iOS8. They still work and I submitted all of my apps without changing anything, but you’ll need to do it sometime. Now that my apps are all updated for the new phones, I have some time to do these type of nice to have’s. At first glance it appears difficult to update, but it really isn’t that hard.

The first place I updated was in the AppDelegate. I have an alert that asks the user to either start a new session (with new scoring and word choice) or resume the current session (keeping all of the current settings). The old code runs in the applicationWillEnterForeground method.

- (void)applicationWillEnterForeground:(UIApplication *)application {
    if (self.window.rootViewController) {
        NSString *messageWithTitle = [NSString stringWithFormat:@"Do you want to resume playing %@ or start a new session?", GAME_NAME_TITLE];
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Welcome Back"
                                              otherButtonTitles: @"Start New Session",nil];
        [alert show];

Because I want to continue to run the app in versions prior to iOS8, I need to change this to a conditional. The code makes use of a #define from my Project-Prefix.pch

#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)

Then I created two methods, one just has the code from the original alert and the other is new.
- (void)applicationWillEnterForeground:(UIApplication *)application {
    if (self.window.rootViewController) {

            [self displayUIAlertController];
        } else {
            [self displayUIAlertView];

This is the new code. The title is the first line of the alert. The message is the second and additional lines. What’s different about this from the old way is that you add actions using methods with completion blocks. You can do anything in a block that you normally would. I kept mine simple and just called a method. If was writing this just for iOS8, I’d probably put the contents of the method in the block. Note: I could have used UIAlertActionStyleCancel instead of UIAlertActionStyleDefault for the Resume button. If you use the UIAlertActionStyleCancel style, it always appears at the end and is bolded
- (void)displayUIAlertController {

    NSString *alertMessage = [NSString stringWithFormat:@"Do you want to resume playing %@ or start a new session?", GAME_NAME_TITLE];
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Welcome Back"

    // You can add as many actions as you want
    UIAlertAction *startNewSession = [UIAlertAction actionWithTitle:@"Start New Session" 
                                                            handler:^(UIAlertAction *action) {
       [self startNewSession];

    UIAlertAction *doNothingAction = [UIAlertAction actionWithTitle:@"Resume"
                                                            handler:^(UIAlertAction *action) {
                    // Do nothing

    // Add actions to the controller. The order here determines the order in the alert. The last one is bolded.
    [alert addAction:doNothingAction];
    [alert addAction:startNewSession];

    // Finally present the action
    [self.window.rootViewController presentViewController:alert animated:true completion:nil];

Normally you’d display the alert with

[self presentViewController:alert animated:YES completion:nil];

but since this is the app delegate you need to do it slightly different.

This is the old code, just put into a method.

- (void)displayUIAlertView {
    NSString *messageWithTitle = [NSString stringWithFormat:@"Do you want to resume playing %@ or start a new session?", GAME_NAME_TITLE];
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Welcome Back"
                                          otherButtonTitles: @"Start New Session",nil];
    [alert show];

I pulled the code out of the buttonIndex1 section and created a new method that is called by both versions when a new session is started.

#pragma mark - Alert on restart
// buttonIndex 0 is cancel and the game continues
// buttonIndex 1 is Start New Session and the old results are saved and new session started
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    if (buttonIndex == 1) {
        [self startNewSession];

- (void)startNewSession {

    // Delete current results
    [Utilities copyCachedResultsToFile];
    [Utilities removeFileFromCache:@"Results.txt"];
    // When deciding whether to start a new table, compares the current scoringType to previousScoringType
    [Globals sharedInstance].previousScoringType = @"";
    [self.navigationController popToRootViewControllerAnimated:YES];

And this is what it looks like.

UIAlertControler example

Initializing Booleans

I have a globals method that I use to keep track of global values in my apps. It is mostly for options. I override the getter like this. In this example, if trials per round is not set, I initialize it to the #defined value for that app.

- (NSUInteger)trialsPerRound {
    if ( !_trialsPerRound ) _trialsPerRound = TRIALS_PER_ROUND;
    return _trialsPerRound;

I tried to do the same thing for some Booleans, but ran into a problem.

- (BOOL)reviewIgnored {
    if ( !_reviewIgnored ) _reviewIgnored = YES;
    return _reviewIgnored;

I wanted the reviewIgnored value to start at YES if it was not set. But what happened is that when I would change it to NO in the options page it would be fine. But when I called it in my if statement

  if (![Globals sharedInstance].reviewIgnored) {

what happened is that the getter checks its value, sees that it is NO. The if statement says to change reviewIgnored to YES and I get the wrong behaviour.

What I did was put all of my Boolean initialization in th AppDelegate.m file. Problem solved.