Php 统计受plpgsql函数影响的行数

我有以下功能：

CREATE FUNCTION user_delete(IN id INT4)
  RETURNS VOID
AS
  $BODY$
  BEGIN
    SELECT * FROM "user" WHERE user_id = id FOR UPDATE;
    DELETE FROM user_role WHERE user_id = id;
    DELETE FROM user_permission WHERE user_id = id;
    DELETE FROM permission_cache WHERE user_id = id;
    DELETE FROM access WHERE user_id = id;
    DELETE FROM "user" WHERE user_id = id;
  END;
  $BODY$
LANGUAGE plpgsql VOLATILE;

我将其用于PHP PDO：

$stmt = $pdo->prepare('SELECT * FROM user_delete(?)');
$stmt->execute(array($user['id']));

结果现在包含

array(
    array('user_delete' => '')
)

因此

$stmt->rowCount();

总是一个

是否可以解决此问题：通过函数不返回任何内容（因为它是空的），通过rowCount返回受影响行的计数

解决方案：

php:

sql:

我可以使用

setof void

返回类型实现返回零长度结果，但如果我在未找到资源时强制它抛出

PDOException

，则不需要这样做…

您可以使用：

GET DIAGNOSTICS integer_var = ROW_COUNT;

。。并让函数返回计数

例如：

CREATE OR REPLACE FUNCTION user_delete(id int, OUT del_ct int) AS
$func$
DECLARE
   i int;  -- helper var
BEGIN
   DELETE FROM user_role WHERE user_id = $1;
   GET DIAGNOSTICS del_ct = ROW_COUNT;  -- init

   DELETE FROM user_permission WHERE user_id = $1;
   GET DIAGNOSTICS i = ROW_COUNT;  del_ct := del_ct + i;

   DELETE FROM permission_cache WHERE user_id = $1;
   GET DIAGNOSTICS i = ROW_COUNT;  del_ct := del_ct + i;

   DELETE FROM access WHERE user_id = $1;
   GET DIAGNOSTICS i = ROW_COUNT;  del_ct := del_ct + i;

   DELETE FROM "user" WHERE user_id = $1;
   GET DIAGNOSTICS i = ROW_COUNT;  del_ct := del_ct + i;
END
$func$  LANGUAGE plpgsql;

您将此作为第一个声明：

SELECT * FROM "user" WHERE user_id = $1 FOR UPDATE;

但是随后的

DELETE

语句也会锁定该行。没有必要一开始就这么做

添加的

OUT del_ct int

声明了一个

OUT

参数，该参数可以像任何变量一样赋值，并在函数结束时自动返回。它还不需要显式的

返回

声明

CREATE OR REPLACE FUNCTION user_delete(id int, OUT del_ct int) AS
$func$
DECLARE
   i int;  -- helper var
BEGIN
   DELETE FROM user_role WHERE user_id = $1;
   GET DIAGNOSTICS del_ct = ROW_COUNT;  -- init

   DELETE FROM user_permission WHERE user_id = $1;
   GET DIAGNOSTICS i = ROW_COUNT;  del_ct := del_ct + i;

   DELETE FROM permission_cache WHERE user_id = $1;
   GET DIAGNOSTICS i = ROW_COUNT;  del_ct := del_ct + i;

   DELETE FROM access WHERE user_id = $1;
   GET DIAGNOSTICS i = ROW_COUNT;  del_ct := del_ct + i;

   DELETE FROM "user" WHERE user_id = $1;
   GET DIAGNOSTICS i = ROW_COUNT;  del_ct := del_ct + i;
END
$func$  LANGUAGE plpgsql;

SELECT * FROM "user" WHERE user_id = $1 FOR UPDATE;

PERFORM * FROM "user" WHERE user_id = $1 FOR UPDATE;