DECODE

The DECODE function takes an expression or column and compares it to a series of search values. It returns a result value that corresponds to the first matching search value, or the default value NULL if no matches are found.

Syntax

DECODE( <expr> , <search1> , <result1> [ , <search2> , <result2> ... ] [ , <default> ] )

Parameters

Parameter	Description
`expr`	The expression to be evaluated
`search`	A value that `expr` is compared against
`result1`	A value that is returned if `expr` matches `search`

Return

Returns the same type as the argument supplied.

Example

CREATE TABLE test1 (european_size int not null);
INSERT INTO test1 values (8),(9),(10),(11);

SELECT european_size,DECODE(european_size,8,40,9,41,10,42,99) from test1;

+---------------+---------+
|european_size  |decode   |
+---------------+---------+
|8              |40       |
+---------------+---------+
|9              |41       |
+---------------+---------+
|10             |42       |
+---------------+---------+
|11             |99       |
+---------------+---------+