1DELETE(7) PostgreSQL 13.4 Documentation DELETE(7)
2
6 DELETE - delete rows of a table
7
9 [ WITH [ RECURSIVE ] with_query [, ...] ]
10 DELETE FROM [ ONLY ] table_name [ * ] [ [ AS ] alias ]
11 [ USING from_item [, ...] ]
12 [ WHERE condition | WHERE CURRENT OF cursor_name ]
13 [ RETURNING * | output_expression [ [ AS ] output_name ] [, ...] ]
14
16 DELETE deletes rows that satisfy the WHERE clause from the specified
17 table. If the WHERE clause is absent, the effect is to delete all rows
18 in the table. The result is a valid, but empty table.
19 Tip
21 TRUNCATE(7) provides a faster mechanism to remove all rows from a
22 table.
23 There are two ways to delete rows in a table using information
25 contained in other tables in the database: using sub-selects, or
26 specifying additional tables in the USING clause. Which technique is
27 more appropriate depends on the specific circumstances.
28 The optional RETURNING clause causes DELETE to compute and return
30 value(s) based on each row actually deleted. Any expression using the
31 table's columns, and/or columns of other tables mentioned in USING, can
32 be computed. The syntax of the RETURNING list is identical to that of
33 the output list of SELECT.
34 You must have the DELETE privilege on the table to delete from it, as
36 well as the SELECT privilege for any table in the USING clause or whose
37 values are read in the condition.
38
40 with_query
41 The WITH clause allows you to specify one or more subqueries that
42 can be referenced by name in the DELETE query. See Section 7.8 and
43 SELECT(7) for details.
44 table_name
46 The name (optionally schema-qualified) of the table to delete rows
47 from. If ONLY is specified before the table name, matching rows are
48 deleted from the named table only. If ONLY is not specified,
49 matching rows are also deleted from any tables inheriting from the
50 named table. Optionally, * can be specified after the table name to
51 explicitly indicate that descendant tables are included.
52 alias
54 A substitute name for the target table. When an alias is provided,
55 it completely hides the actual name of the table. For example,
56 given DELETE FROM foo AS f, the remainder of the DELETE statement
57 must refer to this table as f not foo.
58 from_item
60 A table expression allowing columns from other tables to appear in
61 the WHERE condition. This uses the same syntax as the FROM clause
62 of a SELECT statement; for example, an alias for the table name can
63 be specified. Do not repeat the target table as a from_item unless
64 you wish to set up a self-join (in which case it must appear with
65 an alias in the from_item).
66 condition
68 An expression that returns a value of type boolean. Only rows for
69 which this expression returns true will be deleted.
70 cursor_name
72 The name of the cursor to use in a WHERE CURRENT OF condition. The
73 row to be deleted is the one most recently fetched from this
74 cursor. The cursor must be a non-grouping query on the DELETE's
75 target table. Note that WHERE CURRENT OF cannot be specified
76 together with a Boolean condition. See DECLARE(7) for more
77 information about using cursors with WHERE CURRENT OF.
78 output_expression
80 An expression to be computed and returned by the DELETE command
81 after each row is deleted. The expression can use any column names
82 of the table named by table_name or table(s) listed in USING. Write
83 * to return all columns.
84 output_name
86 A name to use for a returned column.
87
89 On successful completion, a DELETE command returns a command tag of the
90 form
91 DELETE count
93 The count is the number of rows deleted. Note that the number may be
95 less than the number of rows that matched the condition when deletes
96 were suppressed by a BEFORE DELETE trigger. If count is 0, no rows were
97 deleted by the query (this is not considered an error).
98 If the DELETE command contains a RETURNING clause, the result will be
100 similar to that of a SELECT statement containing the columns and values
101 defined in the RETURNING list, computed over the row(s) deleted by the
102 command.
103
105 PostgreSQL lets you reference columns of other tables in the WHERE
106 condition by specifying the other tables in the USING clause. For
107 example, to delete all films produced by a given producer, one can do:
108 DELETE FROM films USING producers
110 WHERE producer_id = producers.id AND producers.name = 'foo';
111 What is essentially happening here is a join between films and
113 producers, with all successfully joined films rows being marked for
114 deletion. This syntax is not standard. A more standard way to do it is:
115 DELETE FROM films
117 WHERE producer_id IN (SELECT id FROM producers WHERE name = 'foo');
118 In some cases the join style is easier to write or faster to execute
120 than the sub-select style.
121
123 Delete all films but musicals:
124 DELETE FROM films WHERE kind <> 'Musical';
126 Clear the table films:
128 DELETE FROM films;
130 Delete completed tasks, returning full details of the deleted rows:
132 DELETE FROM tasks WHERE status = 'DONE' RETURNING *;
134 Delete the row of tasks on which the cursor c_tasks is currently
136 positioned:
137 DELETE FROM tasks WHERE CURRENT OF c_tasks;
139
141 This command conforms to the SQL standard, except that the USING and
142 RETURNING clauses are PostgreSQL extensions, as is the ability to use
143 WITH with DELETE.
144
146 TRUNCATE(7)
147PostgreSQL 13.4 2021 DELETE(7)