CODEWITHSUNDEEP
postgresql
sibert
sibert

Reputation: 2208

Pick another column value depending on column value (postgresql)

In my frontend application I have a function that is called pick(VALUE,'col1','col2','col3'). If the VALUE is 2 the value in col2 should be picked.

This is very handsome for replacing long code using "case when", "switch case" or "if else" calculations.

I have tried to find a similar function in Postgres, but no luck so far. Seen some function array() and values() mentioned, but cannot find the correct syntax.

The goal is to set an return on of three column values depending on first column value.

Pseudo code (not working):

Select status values(column1,column2,column3)from code

I know I can do this by using "case-when-then-else-end", but I am looking for a shorter way to achieve the same thing.

Jsfiddle showing the principe. But I only want to pick ONE value depending on type:

http://sqlfiddle.com/#!15/e0b41/10

Upvotes: 0

Views: 1124

Answers (1)

krokodilko
krokodilko

Reputation: 36087

You can create an array of values from pr_* columns, then pick one of them in this way:

(array[prl_1,prl_2,prl_3])[code_type]

Here is a simple demo: http://sqlfiddle.com/#!15/e0b41/23

select *,
       (array[prl_1,prl_2,prl_3])[code_type]
from code
left join prl on prl_id =1

Upvotes: 1

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