MySQL DECODE() function

Last update on April 04 2022 13:12:40 (UTC/GMT +8 hours)

DECODE() function

MySQL DECODE() function decodes an encoded string and returns the original string.

Syntax:

DECODE(crypt_str, pass_str);

Arguments:

Name	Description
crypt_str	An encoded string.
pass_str	The password string to decode crypt_str.

Syntax Diagram:

MySQL Version: 5.6

Example:

Code:

SELECT   DECODE(ENCODE('mytext','mykeystring'),'mykeystring');

Explanation:

The above MySQL statement decodes the encoded string 'mytext' as specified in the argument and returns the original string.

Sample Output:

mysql> SELECT DECODE(ENCODE('mytext','mykeystring'),'mykeystring');
+------------------------------------------------------+
| DECODE(ENCODE('mytext','mykeystring'),'mykeystring') |
+------------------------------------------------------+
| mytext                                               | 
+------------------------------------------------------+
1 row in set (0.00 sec)

PHP script:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; 
charset=iso-8859-1" />
<title>example-decode - php mysql examples | w3resource</title>
</head>
<body>
<?php
echo "<h2>Retrieving the decrypted data from encrypted 'description' column from 'testtable' : </h2>";
echo "<table border='1' style='border-collapse: collapse; border-color: silver;'>";
echo "<tr style='font-weight: bold;'>";
echo "<td width='100' align='center'>Description</td><td width='100' align='center'>DECODE(description,'mypassw')</td>";
echo "</tr>";
include("../dbopen.php");
$result = mysql_query("SELECT description,DECODE(description,'mypassw') 
FROM testtable");
while($row=mysql_fetch_array($result))
{
echo "<tr>";
echo "<td align='center' width='200'>" . $row[" description"] . "</td>";
echo "<td align='center' width='200'>" . $row[" DECODE(description,'mypassw')"] . "</td>";
echo "</tr>";
}
echo "</table>";
?>
</body>
</html>

View the example in browser>>

Example : MySQL decode() function using table

Sample table: testtable

Code:

SELECT description, DECODE(description,'mypassw')           
FROM testtable;

Explanation:

The above MySQL statement retrieves the decoded data from encoded 'description' column from 'testtable'.

Sample Output:

mysql> SELECT description, DECODE(description,'mypassw')           
    -> FROM testtable;
+---------------------------+-------------------------------+
| description               | DECODE(description,'mypassw') |
+---------------------------+-------------------------------+
| ^5[@·˜,IÜç¦Éý          | zÝÀâ“x®,ÕCý’              | 
| Ô£^]Žþª_‹m              | myencodetext                  | 
| ÿ»(õ 2ñ«QèªöjD¸=ËTú9Ž! | ›z×•ämù…w¤xÿ&‚ÛjV|3üKÜ     | 
| ^5[@·˜,IÜç¦Éý          | zÝÀâ“x®,ÕCý’              | 
+---------------------------+-------------------------------+
4 rows in set (0.00 sec)

PHP script:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; 
charset=iso-8859-1" />
<title>example1-decode - php mysql examples | w3resource</title>
</head>
<body>
<?php
echo "<h2>Retrieving the decrypted data from encrypted 'description' column from 'testtable' : </h2>";
echo "<table border='1' style='border-collapse: collapse; border-color: silver;'>";
echo "<tr style='font-weight: bold;'>";
echo "<td width='100' align='center'>Description</td><td width='100' align='center'>DECODE(description,'mypassw')</td>";
echo "</tr>";
include("../dbopen.php");
$result = mysql_query("SELECT description,DECODE(description,'mypassw') 
FROM testtable");
while($row=mysql_fetch_array($result))
{
echo "<tr>";
echo "<td align='center' width='200'>" . $row[" description"] . "</td>";
echo "<td align='center' width='200'>" . $row[" DECODE(description,'mypassw')"] . "</td>";
echo "</tr>";
}
echo "</table>";
?>
</body>
</html>

View the example in browser

Online Practice Editor:

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