How to declare a variable in a PostgreSQL query

Question

How do I declare a variable for use in a PostgreSQL 8.3 query?

In MS SQL Server I can do this:

DECLARE @myvar INT
SET @myvar = 5

SELECT *
FROM somew         


        

Answer 1

It depends on your client.

However, if you're using the psql client, then you can use the following:

my_db=> \set myvar 5
my_db=> SELECT :myvar  + 1 AS my_var_plus_1;
 my_var_plus_1 
---------------
             6

If you are using text variables you need to quote.

\set myvar 'sometextvalue'
select * from sometable where name = :'myvar';