# DELETE DELETE — delete rows of a table ## Synopsis ``` [ WITH [ RECURSIVE ] with_query [, ...] ] DELETE FROM [ ONLY ] table_name [ * ] [ [ AS ] alias ] [ USING using_list ] [ WHERE condition | WHERE CURRENT OF cursor_name ] [ RETURNING * | output_expression [ [ AS ] output_name ] [, ...] ] ``` ## Description `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. The result is a valid, but empty table. ### Tip [TRUNCATE](https://www.postgresql.org/docs/10/static/sql-truncate.html)provides a faster mechanism to remove all rows from a table. There are two ways to delete rows in a table using information contained in other tables in the database: using sub-selects, or specifying additional tables in the`USING`clause. Which technique is more appropriate depends on the specific circumstances. The optional`RETURNING`clause causes`DELETE`to compute and return value(s) based on each row actually deleted. Any expression using the table's columns, and/or columns of other tables mentioned in`USING`, can be computed. The syntax of the`RETURNING`list is identical to that of the output list of`SELECT`. You must have the`DELETE`privilege on the table to delete from it, as well as the`SELECT`privilege for any table in the`USING`clause or whose values are read in the`condition`. ## Parameters `with_query` The`WITH`clause allows you to specify one or more subqueries that can be referenced by name in the`DELETE`query. See[Section 7.8](https://www.postgresql.org/docs/10/static/queries-with.html)and[SELECT](https://www.postgresql.org/docs/10/static/sql-select.html)for details. `table_name` The name (optionally schema-qualified) of the table to delete rows from. If`ONLY`is specified before the table name, matching rows are deleted from the named table only. If`ONLY`is not specified, matching rows are also deleted from any tables inheriting from the named table. 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`. `using_list` A list of table expressions, allowing columns from other tables to appear in the`WHERE`condition. This is similar to the list of tables that can be specified in the[`FROM`Clause](https://www.postgresql.org/docs/10/static/sql-select.html#SQL-FROM)of a`SELECT`statement; for example, an alias for the table name can be specified. Do not repeat the target table in the`using_list`, unless you wish to set up a self-join. `condition` An expression that returns a value of type`boolean`. Only rows for which this expression returns`true`will be deleted. `cursor_name` The name of the cursor to use in a`WHERE CURRENT OF`condition. The row to be deleted is the one most recently fetched from this cursor. The cursor must be a non-grouping query on the`DELETE`'s target table. Note that`WHERE CURRENT OF`cannot be specified together with a Boolean condition. See[DECLARE](https://www.postgresql.org/docs/10/static/sql-declare.html)for more information about using cursors with`WHERE CURRENT OF`. `output_expression` An expression to be computed and returned by the`DELETE`command after each row is deleted. The expression can use any column names of the table named by\_`table_name`\_or table(s) listed in`USING`. Write`*`to return all columns. `output_name` A name to use for a returned column. ## Outputs On successful completion, a`DELETE`command returns a command tag of the form ``` DELETE count ``` The`count`*\_is the number of rows deleted. Note that the number may be less than the number of rows that matched the*`condition`*when deletes were suppressed by a*`BEFORE DELETE`*trigger. If*`count`\_is 0, no rows were deleted by the query (this is not considered an error). If the`DELETE`command contains a`RETURNING`clause, the result will be similar to that of a`SELECT`statement containing the columns and values defined in the`RETURNING`list, computed over the row(s) deleted by the command. ## Notes PostgreSQLlets you reference columns of other tables in the`WHERE`condition by specifying the other tables in the`USING`clause. For example, to delete all films produced by a given producer, one can do: ``` DELETE FROM films USING producers WHERE producer_id = producers.id AND producers.name = 'foo'; ``` What is essentially happening here is a join between`films`and`producers`, with all successfully joined`films`rows being marked for deletion. This syntax is not standard. A more standard way to do it is: ``` DELETE FROM films WHERE producer_id IN (SELECT id FROM producers WHERE name = 'foo'); ``` In some cases the join style is easier to write or faster to execute than the sub-select style. ## Examples Delete all films but musicals: ``` DELETE FROM films WHERE kind < > 'Musical'; ``` Clear the table`films`: ``` DELETE FROM films; ``` Delete completed tasks, returning full details of the deleted rows: ``` DELETE FROM tasks WHERE status = 'DONE' RETURNING *; ``` Delete the row of`tasks`on which the cursor`c_tasks`is currently positioned: ``` DELETE FROM tasks WHERE CURRENT OF c_tasks; ``` ## Compatibility This command conforms to theSQLstandard, except that the`USING`and`RETURNING`clauses arePostgreSQLextensions, as is the ability to use`WITH`with`DELETE`. ## See Also [TRUNCATE](https://www.postgresql.org/docs/10/static/sql-truncate.html) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.postgresql.tw/reference/sql-commands/delete.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.