DEV Community

Cover image for Common Table Expressions in Postgresql
Jordan Gamba
Jordan Gamba

Posted on • Updated on

Common Table Expressions in Postgresql

Common Table Expressions (CTEs) are an SQL feature that allows you to define temporary result sets within a SQL query. CTEs make complex queries more readable and easier to manage by breaking them down into smaller, more understandable parts.

CTEs are often used in SELECT, INSERT, UPDATE, or DELETE statements, and they are particularly useful when you need to reference the same subquery multiple times within a larger query.

Here's the basic syntax for creating a CTE in SQL:
Image description

  • WITH: This keyword introduces the CTE definition.

  • cte_name: The name you assign to the CTE. (column1, column2, ...): An optional list of column names for the CTE, which you can specify if you want to define column aliases.

  • AS: Separates the CTE name and the subquery.

  • Your subquery here: This is where you write the subquery that defines the CTE

Image description

Common Table Expressions offer various advantages to SQL Developers which include Improved query organization,Readability, the ability to create recursive queries for tasks like working
with hierarchical data.

In short CTes make SQL developer Codes More cleaner in tasks that involve simple data retrieval to complex analytical operations.

Top comments (0)