how to declare variable in PostgreSQL

Question

I try to declare a variable in a code like this, but it\'s doesn\'t work. Can you tell me what\'s the problem?

ERROR:  syntax error at or near \"VARCHAR\"
LI         


        

Answer 1

Create a new setting in postgresql.conf for custom_variable_classes:

custom_variable_classes = 'var'

Reload the config, you now have the variable "var" available in all your databases.

To create the variable p_country, just use SET:

SET var.p_country = 'US';
SELECT current_setting('var.p_country') AS p_country;

It's not a beauty, but it works.