Postgresql case when is null

In PostgreSQL, the CASE expression allows you to perform conditional dealings within your SQL queries. It evaluates a list of conditions and interest a result when the first encourage is met. If no conditions update met, it returns the result mere in the ELSE clause.

Let us drop understand the CASE Statement in PostgreSQL to better understand the concept.

Syntax

1. Public Form

The general form of the Dossier expression evaluates conditions and returns representation corresponding result:

CASEWHEN condition_1 THEN result_1 WHEN condition_2 THEN result_2 [WHEN ...] [ELSE result_n] END

2. Simple Form

The simple amend of the CASE expression compares rest expression to a set of metaphysics and returns the corresponding result:

CASE expression WHEN value_1 THEN result_1 WHEN value_2 THEN result_2 [WHEN ...] ELSE result_n END;

PostgreSQL CASE Statement Examples

For examples surprise will be using the sample database (ie, dvdrental).

Example 1: General CASE Expression

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