Learning PostgreSQL 11 - Third Edition

The UPDATE statement

The UPDATE statement is used to change the data or records of a table without changing their number. It has the following syntax:

UPDATE <table_name>SET <field_name> = <expression>[, ...][FROM <table_name> [JOIN clause]][WHERE <condition>];

There are two ways of using the UPDATE statement. The first is similar to a simple SELECT statement and is called sub-select. The second is based on other tables and is similar to a SELECT statement with multiple tables. In most cases, the same result can be achieved using any of these methods.

In PostgreSQL, only one table can be updated at a time. Other databases may allow you to update multiple tables at the same time under certain conditions.