Retrieve Data From Mysql Database Using PHP

Today we gonna talk about how to retrieve data from a mysql database. in last three lessons we learned about how to create a connection to database, how to create database & tables and how to insert data. if you have any problem with those things you better read few last post before go through this. ok lets begin.

In this case we have to use Sql SELECT statement through mysql_query() function to fetch the data from mysql tables. There is several options that you can use to fetch data from mysql.

The most common function to use for this is mysql_fetch_array(). this function can return numeric array or associated array maybe in some cases it can return both types. it will return false if there is no values.

Lets look at the sample code below.

//make connection
$con = mysql_connect("localhost","root","123");
//check connection
if(!$con)
{
die('Could not connect to the database:'.mysql_error());
}

//select database
$db=mysql_select_db("my_database",$con);
 if(!$db)
{
die('Could not connect to the database:'.mysql_error());

}
//making sql query string. This table has two columns as name and tp_num (telephone number)
$sql="SELECT * FROM my_table";

//Execute the mysql query and check is execution process is succeeded
$values = mysql_query($con,$sql);
if(isset($values))
{


      while($row=mysql_fetch_array($values))
        {

         echo "Name :".$row['name'];
         echo "Contact Number :".$row['tp_num'];
         echo "<hr/>";
         }
 

mysql_free_result($value);

}
else
{
die('Error Occurred'.mysql_error($con));
}

//close connection
mysql_close($con);

We have use mysql_fetch_array() function here. i have sent only one argument to it in my case. but it can handle two paremeter inputs.  mysql_fetch_array(return_value_of_mysql_query(), MYSQL_ASSOC or MYSQL_NUM).. second argument is optional it can be  MYSQL_ASSOC or MYSQL_NUM.

MYSQL_ASSOC - If you used  MYSQL_ASSOC as second argument function will return row as an associated array.

MYSQL_NUM - If you used MYSQL_NUM as second argument it will return row with numeric index.

There is a another function that you can use for fetch data from mysql. that is mysql_fetch_assoc() it's also return row as an associated array.

You can see that at the end of while loop i have used new function call  mysql_free_result(). this function is use to release cursor memory. it is good practice to release memory at the end.

Try to play with codes and try to do this by your own. Cheers..