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iPhone app purchasers may sue Apple over allegations that the company monopolized the market for iPhone apps by not allowing users to purchase them outside the App Store, leading to higher prices, a U.S. appeals court ruled. From a report on Reuters: The 9th U.S. Circuit Court of Appeals ruling revives a long-simmering legal challenge originally filed in 2012 taking aim at Apple’s practice of only allowing iPhones to run apps purchased from its own App Store. A group of iPhone users sued saying the Cupertino, California, company’s practice was anticompetitive. Apple had argued that users did not have standing to sue it because they purchased apps from developers, with Apple simply renting out space to those developers. Developers pay a cut of their revenues to Apple in exchange for the right to sell in the App Store.

Read more of this story at Slashdot.

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US Appeals Court Revives Antitrust Lawsuit Against Apple

In the first two blogs entries on this series we set up a connection to MySQL and sent off a query. Now we need to get the data back from the database and into the application.

An Embarrassment of Riches

PHP has many options for what we want to do. But for the best place to start with was checking that rows were actually returned from a query. Below the results from a query are returned to a variable named $result. We can find out how many rows were returned from the server by examining $result->num_rows.

if (!$result = $mysqli->query($sql)) {

 // Again, do not do this on a public site, but we'll show you how
 // to get the error information
 echo "Error: Our query failed to execute and here is why: \n";
 echo "Query: " . $sql . "\n";
 echo "Errno: " . $mysqli->errno . "\n";
 echo "Error: " . $mysqli->error . "\n";
 exit;
}

// succeeded, but do we have a result?
if ($result->num_rows === 0) {
 // Oh, no rows! Sometimes that's expected and okay, sometimes
 // it is not. You decide.
 echo "No data returned.";
 exit;
}

This is a case where a programmer needs to know their data. In some cases you will not have a record or records returned because there is no data. Other times no data returned is a sign of big problems. So you have to have some education on what you expect back, and what you do not expect back.

Example

<?php
$mysqli = new mysqli("localhost", "root", "hidave", "world_x");

/* check connection */
if ($mysqli->connect_errno) {
 printf("Connect failed: %s\n", $mysqli->connect_error);
 exit();
}

/* Select queries return a resultset */
$query="SELECT Name, CountryCode, District FROM city LIMIT 10";

if ($result = $mysqli->query($query)) {

 if ($result->num_rows){
 printf("Select returned %d rows.\n", $result->num_rows);

 /* free result set */
 $result->close();
 } else {
 echo "No data returned";
 }
} else { // if ($result)
 printf("Query failed: %s", $mysqli_error);
}

$mysqli->close();
?>

Sometime you just need the number of records, like number of outstanding customer orders. But in this case we are making sure we have some data to work with before proceedings.

So Now We Have Data

Now you have at least three choices — rare, medium, or well done. Err, make that an associative array, an array or an object. Each have their uses and it is okay to have a favorite you use more.

$query="SELECT Name, CountryCode, District FROM city LIMIT 10";

if ($result = $mysqli->query($query)) {

 if ($result->num_rows){
 printf("Select returned %d rows.\n", $result->num_rows);
$assoc = $result->fetch_assoc();
 $row = $result->fetch_row();
 $obj = $result->fetch_object();
 } else {
 echo "No data returned";
 }
} else { // if ($result)
 printf("Query failed: %s", $mysqli_error);
}

So you make you choice of method and take the results. Here we use fetch_assoc(), fetch_row(), or fetch_object(). Depending on how you want to refer to the data, you use the one that fits the situation. Of course they are similar in use.

//associated array keys = column name, data = data from DB
printf("Sample assoc array %s -> %s\n", $assoc['Name'], $assoc['CountryCode']);

// simple row
printf("Sample row array %s -> %s\n", $row[0], $row[1]);

//object
printf("Sample object %s -> %s\n", $obj->Name, $obj->CountryCode);

Yes, you need to know all three as you will be looking at old code or someone else code that does not use your favorite. And sometimes you may need an object rather than a simple row.

Full Listing

<?php
$mysqli = new mysqli("localhost", "root", "hidave", "world_x");

/* check connection */
if ($mysqli->connect_errno) {
 printf("Connect failed: %s\n", $mysqli->connect_error);
 exit();
}

/* Select queries return a resultset */
$query="SELECT Name, CountryCode, District FROM city LIMIT 10";

if ($result = $mysqli->query($query)) {

 if ($result->num_rows){
 printf("Select returned %d rows.\n", $result->num_rows);
 $assoc = $result->fetch_assoc();
 $row = $result->fetch_row();
 $obj = $result->fetch_object();
 } else {
 echo "No data returned";
 }
} else { // if ($result)
 printf("Query failed: %s", $mysqli_error);
}
//associated array keys = column name, data = data from DB
printf("Sample assoc array %s -> %s\n", $assoc['Name'], $assoc['CountryCode']);

// simple row
printf("Sample row array %s -> %s\n", $row[0], $row[1]);

//object
printf("Sample object %s -> %s\n", $obj->Name, $obj->CountryCode);

$result->close();
$mysqli->close();
?>

via Planet MySQL
PHP and MySQL Basics III — Resulting Results

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Dilbert 2017-01-12

Ruger has a winner on its hands with their American Rifle series. The guns are priced for value conscious shooters but punch above their weight with some fantastic features and…

The post New From Ruger: American Rimfire Target Model Rifles appeared first on The Truth About Guns.

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New From Ruger: American Rimfire Target Model Rifles

Last time we set up a connection from a PHP program to a MySQL server. This time we will progress a little further in that direction.

Query

Data is asked for from the MySQL server by using a query written in a language named Structured Query Language (SQL). Now that we have a connection open to the server, we can pass out request to the server.

Manual Labor

The PHP Manual is wonderful 99% of time. If you take a peek at the page for mysqli::query there is a great example of a simple query. Many of learned to program by copying/pasting from books/manuals and this is a great us of the examples in the PHP manual. Except it may not work for you.

MySQL is usually case SeNsATiVe, so ‘A’ may not be the same thing as ‘a’. But this is dependent to some extent on your operating system where ‘A’ = ‘a’. I was using the example from the manual and … it did not work.

What Happened

Here is an excerpt of the code, somewhat cut down:

<?php
$mysqli = new mysqli("localhost", "user", "secret", "world_x");

/* check connection */
if ($mysqli->connect_errno) {
    printf("Connect failed: %s\n", $mysqli->connect_error);
    exit();
}

$mysqli->close();
?>

Run the program and … nothing.

So What Happened?

What happened is a subtle problem that novices will smack into very hard. Take a look at this section of the example.

/* Select queries return a resultset */
if ($result = $mysqli->query("SELECT Name FROM City LIMIT 10")) {
    printf("Select returned %d rows.\n", $result->num_rows);

    /* free result set */
    $result->close();
}

If you try the query SELECT Name FROM City LIMIT 10; with the MySQL command line client program you will get the answer. And the answer is:

mysql> SELECT Name FROM City LIMIT 10;
ERROR 1146 (42S02): Table 'world_x.City' doesn't exist
mysql>

I am using the new world_x example database where the city is NOT capitalized instead of the old world database where it is! This lesson can be summed as check you schema/table/column names for case sensitivity. Except that there is another problem here.

In the real world occasional the database/table/column that you carefully double checked was spelled correctly and with the proper case sensitivity will go away. It may have been renamed, deleted, munged, or what have you. What is needed is a way to check to see if there was an error if the query can not run.

Lets change the code slightly:

/* Select queries return a resultset */
if ($result = $mysqli->query("SELECT Name FROM City LIMIT 10")) {
 printf("Select returned %d rows.\n", $result->num_rows);

 /* free result set */
 $result->close();
} else {
 printf("Query failed: %s\n", $mysqli->error);
}

Always Check for Return Codes

By simply adding about 40 characters, the reliability of the program shoots up immensely AND we get an exact answer if what went wrong.

Query failed: Table 'world_x.City' doesn't exist

Same error as when we tried by query by hand. But now our code can handle this issue. We could even try to catch the error, send a note via a message queue to the operations staff about the nature of the problem, and possible limp along until things are resolved. Or we could just call exit()

When you are offered a return code be sure to check it. Yes, it may be over kill in simple examples. But the payoff comes when things go bad and you are scrambling to find out eleven months from now why your program is suddenly not working.
via Planet MySQL
PHP and MySQL Basics II – Case Sense

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Screen Junkies digs 30 years into the vaults to pay tribute to one of our all-time favorites. It’s got adventure, dark humor, romance, and a wealth of memorable characters and lines we still quote to this day. Also, we felt exactly like Fred Savage as the story unfolded.

via The Awesomer
Honest Princess Bride Trailer

PHP and MySQL have had a long intertwined path together. I have been talking with a lot of newbies in the past several months who are trying to become PHP developers but are amazed at all the ancillary parts that go along with PHP such as unit testing, databases, JavaScript, continuous integration, and much more. Add in that there are two MySQL APIs — PDO & MySQLi — and an older deprecated mysql API still often found in the wild. This blog is the start of a series for new PHP developers to learn to program with a database.

Client Server Model

The PHP code when it seeks to talk to a MySQL (or most other databases) will make a connection to a port at an IP address. Usually MySQL is listening on port 3306. If you are developing an accessing a database on your local computer the IP address used will generally be at 127.0.0.1. The software that goes between the PHP application and the database is called a connector.

So your code on you local system an be talking to a database server on your local system or through a network connection. It does not matter which.

Can’t connect to MySQL server on ‘x.x.x.x’ (111)

The Can’t connect error can be especially frustrating. An experienced developer will know what to check from tears of experience. But this is a column on basics so we need to spell out the steps.

1. Is the IP address correct? It is easy to fat finger IP address and ironically 127.0.01 on many Linux boxes will connect up to 127.0.0.1.
2. Is there a instance of MySQL running at that IP address?
3. Is that instance listening on the generic port 3306? Is may be running someplace else and you will have to chance down that port number.
4. Can the MySQL command line shell or other tool connect to the instance? MySQL Workbench, PhPMyAdmin, the cli tools, and everything else authenticate through the same steps so if they work and your PHP program does not then most likely the fault is in the PHP code.

Setting up the client server connection

The PHP Manual is worth its weight in gold and you should refer to it often. Its examples are clear, or usually as clear as can be, and concise. Below is an excerpt example from the manual.

<?php

$mysqli = new mysqli("127.0.0.1", "user", "password", "database", 3306);
if ($mysqli->connect_errno) {
 echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
}

echo $mysqli->host_info . "\n";
?>

Note that the IP address, user name of "user", password of "password", and the port of 3306 will need to be changed to fit the installation. The mysqli call sets up the connection between the application and the MySQL database server.

Please note that you should protect usernames and password or any other information that could allow someone to compromise the server and data.

The if statement is invoked when there is an error code is returned from the $mysql->connect_errono call. Subsequently the error message from the server can be printed out using $mysqli->error. The error message itself can be terse but often points out what is wrong in the code.

Bad arguments

What follows below are three bad connection strings.

// Bad IP address
$mysqli = new mysqli("19.10.0.3", "root", "barfoo", "world_x", 3306);
if ($mysqli->connect_errno) {
 echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
}

// Bad account information
$mysqli = new mysqli("127.0.0.1", "root", "foobar", "world_x", 3306);
if ($mysqli->connect_errno) {
 echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
}

// Bad database specified
$mysqli = new mysqli("127.0.0.1", "root", "foobar", "world_xx\", 3306);
if ($mysqli->connect_errno) {
 echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
}

Part of mastering any computer programming language is learning to understand the error messages. The three examples above return similar but distinctly different messages.

The first of the trip provides the following error:

PHP Warning:  mysqli::__construct(): (HY000/2002): Network is unreachable in /home/dstokes/php/m02.php 
Failed to connect to MySQL: (2002) Network is unreachable

It would be nice to get more information than ‘Network in unreachable’ but it provides a starting point to diagnose the problem. Generally the more specific the problem, the more specific the error message.

The third of the trio attempts to connect to a database named ‘world_xx’ when we really wanted ‘world_x’.

PHP Warning: mysqli::__construct(): (HY000/1049): Unknown database 'world_xx' in /home/dstokes/php/m02.php
Failed to connect to MySQL: (1049) Unknown database 'world_xx'

Sadly for beginners it takes time and experience to get to the point where you can instantly look at an error and know what has gone wrong (or have a pretty good idea of what has gone wrong). But do not worry as many of us learn by correcting OUR mistakes and learning not to repeat them.

Connection Good

So after establishing a good connection to the MySQL server, we can now query it for data.

Next Time — what happened to my query??

via Planet MySQL
PHP and MySQL Basics

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Designer Daniel Ballou and Dashdot are working on this cool DIY audio system which lets you take ordinary cinder blocks and turn them into speakers. Apparently, the concrete minimizes vibration and coloration of sound. Ballou hopes to retail the kit for about $150.

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Cinder Speakers

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The Best 6 Sites to Get Free Ebooks

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An old segment from How It’s Made which shows how a steel rod is gradually made thinner and thinner, then run through a metal shaving machine, and woven together to transform it into the scrubby cleaning material we’re familiar with.

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How Steel Wool Is Made