DECODE

Syntax

DECODE(crypt_str,pass_str)

In Oracle mode from MariaDB 10.3.2:

DECODE(expr, search_expr, result_expr [, search_expr2, result_expr2 ...] [default_expr])

In all modes from MariaDB 10.3.2:

DECODE_ORACLE(expr, search_expr, result_expr [, search_expr2, result_expr2 ...] [default_expr])

Description

In the default mode, DECODE decrypts the encrypted string crypt_str using pass_str as the password. crypt_str should be a string returned from ENCODE(). The resulting string will be the original string only if pass_str is the same.

In Oracle mode from MariaDB 10.3.2, DECODE compares expr to the search expressions, in order. If it finds a match, the corresponding result expression is returned. If no matches are found, the default expression is returned, or NULL if no default is provided.

NULLs are treated as equivalent.

DECODE_ORACLE is a synonym for the Oracle-mode version of the function, and is available in all modes.

Examples

From MariaDB 10.3.2:

SELECT DECODE_ORACLE(2+1,3*1,'found1',3*2,'found2','default');
+--------------------------------------------------------+
| DECODE_ORACLE(2+1,3*1,'found1',3*2,'found2','default') |
+--------------------------------------------------------+
| found1                                                 |
+--------------------------------------------------------+

SELECT DECODE_ORACLE(2+4,3*1,'found1',3*2,'found2','default');
+--------------------------------------------------------+
| DECODE_ORACLE(2+4,3*1,'found1',3*2,'found2','default') |
+--------------------------------------------------------+
| found2                                                 |
+--------------------------------------------------------+

SELECT DECODE_ORACLE(2+2,3*1,'found1',3*2,'found2','default');
+--------------------------------------------------------+
| DECODE_ORACLE(2+2,3*1,'found1',3*2,'found2','default') |
+--------------------------------------------------------+
| default                                                |
+--------------------------------------------------------+

Nulls are treated as equivalent:

SELECT DECODE_ORACLE(NULL,NULL,'Nulls are equivalent','Nulls are not equivalent');
+----------------------------------------------------------------------------+
| DECODE_ORACLE(NULL,NULL,'Nulls are equivalent','Nulls are not equivalent') |
+----------------------------------------------------------------------------+
| Nulls are equivalent                                                       |
+----------------------------------------------------------------------------+