PHP-MySQL Lesson: The Where Clause

The Where Clause

In this lesson we are going to write PHP scripts that select a specific records in MySQL using the WHERE clause

Using WHERE clause we can specify a selection criteria to select, update,delete required records from a table.

We can execute any sql query like insert, update, delete, select etc. using the mysql_query() function.Here is the code: name it as php_where.php

<?php
//including the database connection file

include("mysql_connect.php");
mysql_select_db("employee");

$result = mysql_query("SELECT * FROM employee_record where l_name=’Piolo’");

echo "<table border='1'>
<tr>
<th>ID</th>
<th>Firstname</th>
<th>Lastname</th>
<th>Position</th>
<th>Age</th>
<th>Salary</th>
<th>Email</th>
</tr>";
while($row = mysql_fetch_array($result))
{
echo "<tr>";
echo "<td>".$row['id']."</td>";
echo "<td>".$row['f_name']."</td>";
echo "<td>".$row['l_name']."</td>";
echo "<td>".$row['position']."</td>";
echo "<td>".$row['age']."</td>";
echo "<td>".$row['salary']."</td>";
echo "<td>".$row['email']."</td>";  echo "</tr>";
}
echo "</table>";
?>

In the above example it will display the record of the employee whose f_name is equal to Piolo.

In our example we have used include() function, this function takes all the content in a specified file and includes it in the current file.

Then, we have selected the employee database using the mysql_select_db() function.

Next, we have declared a variable $result that will store the value returned by mysql_query() function.

Next, we use the mysql_fetch_array() function to fetch a row from a recordset as an array.

Then, we place the mysql_fetch_array() function within the conditional statement of the while loop. It means that the while loop will continue to execute as long as there a row to fetch.