Question

I am writing a script using DBI to execute a select query to an Oracle db. I have successfully able to capture the data but I need help to change the output.

Below is the sample output.

Type
2
6

I want to display 2=>Good and 6=>Bad

Can anyone please suggest me the Perl code to map the output?

Answer 1

Usually the easiest way is to change directly the values outputted by the SQL query. With Oracle you can use DECODE.

SELECT DECODE(MY_TYPE, 2, 'TWO', 6, 'SIX', 'DEFAULT_VALUE') FROM MY_TABLE

The standard SQL way is to use a CASE conditional expression. It is a little more verbose, but more powerful and more portable. It works for example in Oracle, PostgreSQL and MS-SQL.

SELECT 
    CASE 
        WHEN MY_TYPE = 2 THEN 'TWO'
        WHEN MY_TYPE = 6 THEN 'SIX'
        ELSE 'DEFAULT_VALUE'
    END CASE 
FROM MY_TABLE

If you still want to do it in Perl, you might create a Hash. The code sample is quite trivial, and well documented in the link I provided.