To assign the return value of a SQL query to a psql variable, the following process can be followed:
Declare the psql variable using the command \set variable_name value
.
Write the SQL query to retrieve the required data.
Use the SELECT
statement to execute the SQL query and assign the result to the psql variable.
Use the :variable_name
notation to reference the psql variable in subsequent commands.
Example:
-- Declare psql variable
\set customer_count 0
-- SQL query to retrieve customer count
SELECT COUNT(*) FROM customers;
-- Assign result to psql variable
\set customer_count :SELECT
-- Use psql variable in subsequent commands
SELECT * FROM orders WHERE customer_id = :customer_count;
Asked: 2023-06-21 09:56:05 +0000
Seen: 11 times
Last updated: Jun 21 '23