Postgresql 中文操作指南

ALTER FUNCTION

ALTER FUNCTION - 更改函数定义

ALTER FUNCTION — change the definition of a function

Synopsis

ALTER FUNCTION name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]
    action [ ... ] [ RESTRICT ]
ALTER FUNCTION name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]
    RENAME TO new_name
ALTER FUNCTION name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]
    OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER FUNCTION name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]
    SET SCHEMA new_schema
ALTER FUNCTION name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]
    [ NO ] DEPENDS ON EXTENSION extension_name

where action is one of:

    CALLED ON NULL INPUT | RETURNS NULL ON NULL INPUT | STRICT
    IMMUTABLE | STABLE | VOLATILE
    [ NOT ] LEAKPROOF
    [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER
    PARALLEL { UNSAFE | RESTRICTED | SAFE }
    COST execution_cost
    ROWS result_rows
    SUPPORT support_function
    SET configuration_parameter { TO | = } { value | DEFAULT }
    SET configuration_parameter FROM CURRENT
    RESET configuration_parameter
    RESET ALL

Description

ALTER FUNCTION 更改函数定义。

ALTER FUNCTION changes the definition of a function.

您必须拥有使用 ALTER FUNCTION 的权限。要更改函数架构，您还必须在新架构上拥有 CREATE 权限。要更改所有者，您必须能向新的拥有者角色 SET ROLE ，且该角色必须对函数架构拥有 CREATE 权限。（这些限制的作用是确保更改所有者不会执行您通过删除和重新创建该函数而无法执行的操作。不过，超级用户可以随意更改任何函数的所有权。）

You must own the function to use ALTER FUNCTION. To change a function’s schema, you must also have CREATE privilege on the new schema. To alter the owner, you must be able to SET ROLE to the new owning role, and that role must have CREATE privilege on the function’s schema. (These restrictions enforce that altering the owner doesn’t do anything you couldn’t do by dropping and recreating the function. However, a superuser can alter ownership of any function anyway.)

Parameters

  • name

    • The name (optionally schema-qualified) of an existing function. If no argument list is specified, the name must be unique in its schema.

  • argmode

    • The mode of an argument: IN, OUT, INOUT, or VARIADIC. If omitted, the default is IN. Note that ALTER FUNCTION does not actually pay any attention to OUT arguments, since only the input arguments are needed to determine the function’s identity. So it is sufficient to list the IN, INOUT, and VARIADIC arguments.

  • argname

    • The name of an argument. Note that ALTER FUNCTION does not actually pay any attention to argument names, since only the argument data types are needed to determine the function’s identity.

  • argtype

    • The data type(s) of the function’s arguments (optionally schema-qualified), if any.

  • new_name

    • The new name of the function.

  • new_owner

    • The new owner of the function. Note that if the function is marked SECURITY DEFINER, it will subsequently execute as the new owner.

  • new_schema

    • The new schema for the function.

  • DEPENDS ON EXTENSION _extension_nameNO DEPENDS ON EXTENSION _extension_name

    • This form marks the function as dependent on the extension, or no longer dependent on that extension if NO is specified. A function that’s marked as dependent on an extension is dropped when the extension is dropped, even if CASCADE is not specified. A function can depend upon multiple extensions, and will be dropped when any one of those extensions is dropped.

  • CALLED ON NULL INPUT_RETURNS NULL ON NULL INPUT_STRICT

    • CALLED ON NULL INPUT changes the function so that it will be invoked when some or all of its arguments are null. RETURNS NULL ON NULL INPUT or STRICT changes the function so that it is not invoked if any of its arguments are null; instead, a null result is assumed automatically. See CREATE FUNCTION for more information.

  • IMMUTABLE_STABLE_VOLATILE

    • Change the volatility of the function to the specified setting. See CREATE FUNCTION for details.

  • [ EXTERNAL ] SECURITY INVOKER_[ EXTERNAL ] SECURITY DEFINER_

    • Change whether the function is a security definer or not. The key word EXTERNAL is ignored for SQL conformance. See CREATE FUNCTION for more information about this capability.

  • PARALLEL

    • Change whether the function is deemed safe for parallelism. See CREATE FUNCTION for details.

  • LEAKPROOF

    • Change whether the function is considered leakproof or not. See CREATE FUNCTION for more information about this capability.

  • COST execution_cost

    • Change the estimated execution cost of the function. See CREATE FUNCTION for more information.

  • ROWS result_rows

    • Change the estimated number of rows returned by a set-returning function. See CREATE FUNCTION for more information.

  • SUPPORT support_function

    • Set or change the planner support function to use for this function. See Section 38.11 for details. You must be superuser to use this option.

    • This option cannot be used to remove the support function altogether, since it must name a new support function. Use CREATE OR REPLACE FUNCTION if you need to do that.

  • configuration_parameter__value

    • Add or change the assignment to be made to a configuration parameter when the function is called. If value is DEFAULT or, equivalently, RESET is used, the function-local setting is removed, so that the function executes with the value present in its environment. Use RESET ALL to clear all function-local settings. SET FROM CURRENT saves the value of the parameter that is current when ALTER FUNCTION is executed as the value to be applied when the function is entered.

    • See SET and Chapter 20 for more information about allowed parameter names and values.

  • RESTRICT

    • Ignored for conformance with the SQL standard.

Examples

将 integer 类型函数 sqrt 重命名为 square_root ：

To rename the function sqrt for type integer to square_root:

ALTER FUNCTION sqrt(integer) RENAME TO square_root;

将 integer 类型函数 sqrt 的所有者更改为 joe ：

To change the owner of the function sqrt for type integer to joe:

ALTER FUNCTION sqrt(integer) OWNER TO joe;

将 integer 类型函数 sqrt 的模式更改为 maths ：

To change the schema of the function sqrt for type integer to maths:

ALTER FUNCTION sqrt(integer) SET SCHEMA maths;

将 integer 类型函数 sqrt 标记为依赖于扩展 mathlib ：

To mark the function sqrt for type integer as being dependent on the extension mathlib:

ALTER FUNCTION sqrt(integer) DEPENDS ON EXTENSION mathlib;

调整自动为函数设置的搜索路径：

To adjust the search path that is automatically set for a function:

ALTER FUNCTION check_password(text) SET search_path = admin, pg_temp;

禁用为函数自动设置 search_path ：

To disable automatic setting of search_path for a function:

ALTER FUNCTION check_password(text) RESET search_path;

此函数将使用其调用者使用的任何搜索路径执行。

The function will now execute with whatever search path is used by its caller.

Compatibility

此语句与 SQL 标准中的 ALTER FUNCTION 语句部分兼容。该标准允许修改函数的更多属性，但无法重命名函数、使函数成为安全定义，将配置参数值附加到函数，或者更改函数的所有者、模式或波动性。该标准还需要 RESTRICT 关键字，但是在 PostgreSQL 中该关键字是可选的。

This statement is partially compatible with the ALTER FUNCTION statement in the SQL standard. The standard allows more properties of a function to be modified, but does not provide the ability to rename a function, make a function a security definer, attach configuration parameter values to a function, or change the owner, schema, or volatility of a function. The standard also requires the RESTRICT key word, which is optional in PostgreSQL.

See Also

CREATE FUNCTION 、 DROP FUNCTION 、 ALTER PROCEDURE 、 ALTER ROUTINE

CREATE FUNCTION, DROP FUNCTION, ALTER PROCEDURE, ALTER ROUTINE