MySQL DECODE() function
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: 8.0
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.
Output:
mysql> SELECT DECODE(ENCODE('mytext','mykeystring'),'mykeystring');
+------------------------------------------------------+
| DECODE(ENCODE('mytext','mykeystring'),'mykeystring') |
+------------------------------------------------------+
| mytext                                               | 
+------------------------------------------------------+
1 row in set (0.00 sec)
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'.
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! | ›zוämù…w¤xÿ&‚ÛjV|3üKÜ     | 
| ^5[@·˜,IÜç¦Éý          | zÝÀâ“x®,ÕCý’              | 
+---------------------------+-------------------------------+
4 rows in set (0.00 sec)
 Previous: COMPRESS()
Next:  DES_DECRYPT()
