mysql_fetch_array: Why Use It?

Do you know what is returned when you used the mysql_query function to query a MySQL database? It isn’t something you can directly manipulate, that is for sure. Here is a sample SELECT query of a table we created in the MySQL Create Table lesson.

<?php
$result = mysql_query("SELECT * FROM example");
?>

The value that mysql_query returns and stores into $result is a special type of data, it is a MySQL Resource. Additional PHP functions are required to extract the data from this Resource.

A Row of Data

The mysql_fetch_array function takes a MySQL query resource as an argument ($result) and returns the first row of data returned by the mysql_query. Our table example basically looks like the table below.

example MySQL Table:

The first row of data in this table is “Timmy Mellowman” and “23″. When we fetch an array from our MySQL Resource $result it should have Timmy’s name and age in it.

Getting a Row of Data using mysql_fetch_array

mysql_fetch_array returns the first row in a MySQL Resource in the form of an associative array. The columns of the MySQL Result can be accessed by using the column names of the table. In our table example these are: name and age. Here is the code to print out the first MySQL Result row.

<?php
// Make a MySQL Connection
$query = "SELECT * FROM example"; 

$result = mysql_query($query) or die(mysql_error());

$row = mysql_fetch_array($result) or die(mysql_error());
echo $row['name']. " - ". $row['age'];
?>

Display:

This is just what we expected would happen! Now, the cool thing about mysql_fetch_array is that you can use it again on the same MySQL Resource to return the second, third, fourth and so on rows. You can keep doing this until the MySQL Resource has reached the end (which would be three times in our example).

Sounds like an awfully repetitive task. It would be nice if we could get all our results from a MySQL Resource in an easy to do script.

Fetch Array While Loop

As we have said, the mysql_fetch_array function returns an associative array, but it also returns FALSE if there are no more rows to return! Using a PHP While Loop we can use this information to our advantage.

If we place the statement “$row = mysql_fetch_array()” as our while loop’s conditional statement we will accomplish two things:

1. We will get a new row of MySQL information that we can print out each time the while loop checks its conditional statement.
2. When there are no more rows the function will return FALSE causing the while loop to stop!

Now that we know what we need to do and how to go about doing it, the code pretty much writes itself, so let’s move on to the next lesson. Just kidding! Here is the code that will print out all the rows of our MySQL Resource.

<?php
// Make a MySQL Connection
$query = "SELECT * FROM example"; 

$result = mysql_query($query) or die(mysql_error());

while($row = mysql_fetch_array($result)){
	echo $row['name']. " - ". $row['age'];
	echo "<br />";
}
?>

Display:

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