> For the complete documentation index, see [llms.txt](https://docs.postgresql.tw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.postgresql.tw/reference/sql-commands/sql-call.md).

# CALL

### CALL

CALL — invoke a procedure

### Synopsis

```

CALL name ( [ argument ] [, ...] )
```

### Description

`CALL` executes a procedure.

If the procedure has any output parameters, then a result row will be returned, containing the values of those parameters.

### Parameters

*`name`* : The name (optionally schema-qualified) of the procedure.

*`argument`* : An argument expression for the procedure call.

```
Arguments can include parameter names, using the syntax
`name => value`.
This works the same as in ordinary function calls; see
[Section 4.3](../../the-sql-language/sql-syntax/sql-syntax-calling-funcs.md) for details.

Arguments must be supplied for all procedure parameters that lack
defaults, including `OUT` parameters. However,
arguments matching `OUT` parameters are not evaluated,
so it's customary to just write `NULL` for them.
(Writing something else for an `OUT` parameter
might cause compatibility problems with
future PostgreSQL versions.)
```

### Notes

The user must have `EXECUTE` privilege on the procedure in order to be allowed to invoke it.

To call a function (not a procedure), use `SELECT` instead.

If `CALL` is executed in a transaction block, then the called procedure cannot execute transaction control statements. Transaction control statements are only allowed if `CALL` is executed in its own transaction.

PL/pgSQL handles output parameters in `CALL` commands differently; see [Section 41.6.3](/server-programming/plpgsql/plpgsql-control-structures.md#PLPGSQL-STATEMENTS-CALLING-PROCEDURE).

### Examples

```

CALL do_db_maintenance();
```

### Compatibility

`CALL` conforms to the SQL standard, except for the handling of output parameters. The standard says that users should write variables to receive the values of output parameters.

### See Also

[CREATE PROCEDURE](/reference/sql-commands/sql-createprocedure.md)

***

原文：[PostgreSQL 18.6 Documentation](https://www.postgresql.org/docs/18/sql-call.html)（英文原文，待翻譯）


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