Delete

Introduction

DELETE: deletes rows that satisfy the WHERE clause from the specified table. If the WHERE clause is absent, the effect is to delete all rows in the table.

Synopsis

DELETE FROM table_name [ * ] [ [ AS ] alias ]
    [ WHERE condition  ]

Parameters

table_name: The name of the table to delete rows from. Optionally, * can be specified after the table name to explicitly indicate that descendant tables are included.

alias：A substitute name for the target table. When an alias is provided, it completely hides the actual name of the table. For example, given DELETE FROM foo AS f, the remainder of the DELETE statement must refer to this table as f not foo.

condition：An expression that returns a value of type boolean. Only rows for which this expression returns true will be deleted.

Examples

CREATE TABLE delete_test (
    id INT PRIMARY KEY,
    a INT,
    b text 
);

INSERT INTO delete_test VALUES 
(1, 10, 'a'),
(2, 30, 'b'),
(3, 50,  ''),
(4, 70, null);

DELETE FROM delete_test AS dt WHERE dt.a = 10;

DELETE FROM delete_test AS dt WHERE dt.b is null;

DELETE FROM delete_test AS dt WHERE dt.b='';

For more details about DELETE, please go to official PostgresSQL Documentation DELETE.