Question

在PostgreSQL数据库中，我创建了如下过程：

CREATE OR REPLACE PROCEDURE creator(ID uuid, EMPLOYEES VARCHAR[]) AS $FUNCTION$
  BEGIN
    DELETE FROM SURVEYS_EMPLOYEES_RELATIONSHIP
    WHERE SURVEY_ID = ID
    AND EMPLOYEE NOT IN (EMPLOYEES);
    --
    INSERT INTO SURVEYS_EMPLOYEES_RELATIONSHIP (SURVEY_ID, EMPLOYEE) 
    SELECT SURVEY_ID ID, EMPLOYEE FROM UNNEST(ARRAY[EMPLOYEES]) EMPLOYEE
    ON CONFLICT ON CONSTRAINT unique_key 
    DO NOTHING;
  END;
$FUNCTION$ LANGUAGE plpgsql;

正如您在此过程中所看到的，我尝试先输入DELETE的一些条目，然后再输入INSERT的其他条目。我这样称呼这个程序：

CALL creator('99c89a24-fff2-4cbc-a542-b1e956a352f9', ARRAY['NNogerbek@gmail.com', 'IKim@gmail.com'])

由于某种原因，它会引发错误：

SQL Error [42883]: ERROR: operator does not exist: character varying <> character varying[]
No operator matches the given name and argument types. You might need to add explicit type casts.
PL/pgSQL function creator(uuid,character varying[]) line 3 at SQL statement

我在程序中哪里出错了？

Answer 1

在DELETE查询中，EMPLOYEE NOT IN (EMPLOYEES)不正确。 IN不是在这里“取消嵌套”数组，您最终将varchar与varchar[]进行了比较。

您可以尝试将其替换为

EMPLOYEE NOT IN (SELECT e FROM unnest(EMPLOYEES) u (e))

“手动”取消嵌套数组，

NOT EMPLOYEES @> ARRAY[EMPLOYEE]

使用数组包含运算符或

EMPLOYEE <> ALL (EMPLOYEES)

使用ANY，其中数组自动“取消嵌套”。（可能还有更多。）

PostgreSQL过程：“没有运算符匹配给定的名称和参数类型”

1 个答案: