The MySQL WHERE clause is useful to filter only those records that are fulfilled by the user’s specific condition. The SQL WHERE Clause is useful to restrict the number of rows affected by a SELECT, UPDATE, or DELETE query.
Index
PHP MySQL Where Clause
The WHERE clause works like an if condition in any programming language. The where Clause is useful to compare the given value with the field value available in a MySQL table. If the given value from outside is equal to the available field value in the MySQL table, it returns that row.
Syntax
SELECT Column1 , Column2 , ... FROM Table_Name WHERE Condition
Read Also: PHP MySQL Select Data
WHERE Clause Using Procedural Method
<?php $conn = mysqli_connect("localhost", "user_name", "password", "database"); if($conn === false){ die("ERROR: Could not connect. " . mysqli_connect_error()); } $query = "SELECT * FROM Data WHERE Firstname='ram'"; if($result = mysqli_query($conn, $query)){ if(mysqli_num_rows($result) > 0){ echo "<table>"; echo "<tr>"; echo "<th>Firstname</th>"; echo "<th>Lastname</th>"; echo "<th>Age</th>"; echo "</tr>"; while($row = mysqli_fetch_array($result)){ echo "<tr>"; echo "<td>" . $row['Firstname'] . "</td>"; echo "<td>" . $row['Lastname'] . "</td>"; echo "<td>" . $row['Age'] . "</td>"; echo "</tr>"; } echo "</table>"; mysqli_free_result($result); } else{ echo "No Matching records are found."; } } else{ echo "ERROR: Could not able to execute $sql. " . mysqli_error($conn); } mysqli_close($conn); ?>
WHERE Clause Using Object-Oriented Method
<?php $mysqli = new mysqli("localhost", "user_name", "password", "database"); if($mysqli === false){ die("ERROR: Could not connect. " . $mysqli->connect_error); } $query = "SELECT * FROM Data WHERE Firstname='ram'"; if($result = $mysqli->query($query)){ if($result->num_rows > 0){ echo "<table>"; echo "<tr>"; echo "<th>Firstname</th>"; echo "<th>Lastname</th>"; echo "<th>Age</th>"; echo "</tr>"; while($row = $result->fetch_array()){ echo "<tr>"; echo "<td>" . $row['Firstname'] . "</td>"; echo "<td>" . $row['Lastname'] . "</td>"; echo "<td>" . $row['Age'] . "</td>"; echo "</tr>"; } echo "</table>"; $result->free(); } else{ echo "No matching records are found."; } } else{ echo "ERROR: Could not able to execute $query. " . $mysqli->error; } $mysqli->close(); ?>
WHERE Clause Using PDO Method
<?php try{ $pdo = new PDO("mysql:host=localhost; dbname=database", "user_name", "password"); $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); } catch(PDOException $e) { die("ERROR: Could not connect. " . $e->getMessage()); } try{ $query = "SELECT * FROM Data WHERE Firstname='ram'"; $result = $pdo->query($query); if($result->rowCount() > 0){ echo "<table>"; echo "<tr>"; echo "<th>Firstname</th>"; echo "<th>Lastname</th>"; echo "<th>Age</th>"; echo "</tr>"; while($row = $res->fetch()){ echo "<tr>"; echo "<td>" . $row['Firstname'] . "</td>"; echo "<td>" . $row['Lastname'] . "</td>"; echo "<td>" . $row['Age'] . "</td>"; echo "</tr>"; } echo "</table>"; unset($res); } else{ echo "No records matching are found."; } } catch(PDOException $e) { die("ERROR: Could not able to execute $sql. " . $e->getMessage()); } unset($pdo); ?>
Conclusion
The WHERE Clause is useful to fetch the selected rows from a MySQL table.
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