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

The following shows the correct syntax for the DECODE function:

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

Parameters

The following table shows the DECODE parameters:

Parameter	Description
expr	The expression to be evaluated.
search	A value that expr is compared against.
result1	A value that is returnd 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;

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