Tuesday, 10 July 2018

Mysql MID() function

Mysql MID() function

MySQL MID() extracts a substring from a string. The actual string, position to start extraction and length of the extracted string - all are specified as arguments.
Syntax:
MID(str, pos, len)
Arguments
NameDescription
strA string from which a substring will be extracted.
posAn integer indicating the position (within the str) from where extraction should start.
lenAn integer indicating the length of the extracted string.
The above function is a synonym for SUBSTRING(str,pos,len).
MySQL Version: 5.6
Pictorial Presentation
MySQL MID() pictorial presentation
Example of MySQL MID() function
The following MySQL statement extracts 'eso' by starting extraction from the fourth character of 'w3resource' string and extracting 3 following characters.
Code:
SELECT MID('w3resource',4,3);


Sample Output:
mysql> SELECT MID('w3resource',4,3); 
+-----------------------+
| MID('w3resource',4,3) |
+-----------------------+
| eso                   | 
+-----------------------+
1 row in set (0.02 sec)
Example of MySQL MID() function with where clause
The following MySQL statement extracts a substring from the name of the publishers (pub_name column), starting extraction from the fourth character and continue to extract following five characters; but this is done only if the publisher belongs to the USA.
Code:

SELECT pub_name, MID(pub_name,4,5)
FROM publisher 
WHERE country='USA';


Sample table: publisher

Sample Output:
mysql> SELECT pub_name, MID(pub_name,4,5)
    -> FROM publisher 
    -> WHERE country='USA';
+--------------------------+-------------------+
| pub_name                 | MID(pub_name,4,5) |
+--------------------------+-------------------+
| Jex Max Publication      |  Max              | 
| Mountain Publication     | ntain             | 
| Summer Night Publication | mer N             | 
+--------------------------+-------------------+
3 rows in set (0.06 sec)
PHP script
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>example-mid-function - php mysql examples | w3resource</title>
<meta name="description" content="example-mid-function - php mysql examples | w3resource">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
</head>
<body>
<div class="container">
<div class="row">
<div class="col-md-12">
<h2>A list of Publishers and a string from the name which starting at position four and five characters long:</h2>
<table class='table table-bordered'>
<tr>
<th>Output</th><th>MID(pub_name,4,5)</th>
</tr>
<?php
$hostname="your_hostname";
$username="your_username";
$password="your_password";
$db = "your_dbname";
$dbh = new PDO("mysql:host=$hostname;dbname=$db", $username, $password);
foreach($dbh->query('SELECT pub_name, MID(pub_name,4,5)
FROM publisher
WHERE country="USA"') as $row) {
echo "<tr>";
echo "<td>" . $row['pub_name'] . "</td>";
echo "<td>" . $row['MID(pub_name,4,5)'] . "</td>";
echo "</tr>";
}
?>
</tbody></table>
</div>
</div>
</div>
</body>
</html>

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