postgresqlHow do I use the WITH statement in PostgreSQL?
The WITH statement in PostgreSQL is a convenient way to write complex queries. It allows you to define a set of subqueries which can then be used in the main query. This makes it easier to read and debug complex queries.
Here is an example of a WITH statement:
WITH subquery1 AS (
SELECT *
FROM table1
),
subquery2 AS (
SELECT *
FROM table2
)
SELECT *
FROM subquery1
JOIN subquery2
ON subquery1.id = subquery2.id;
This query consists of two subqueries, subquery1
and subquery2
, which are defined in the WITH
clause. These subqueries are then used in the main SELECT
statement.
Code explanation
WITH
clause: This is where the subqueries are defined.- Subqueries: These are the queries that are defined in the
WITH
clause. SELECT
statement: This is the main query that uses the subqueries defined in theWITH
clause.
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