PL SQL 循环遍历 id 列表

Question

我有一个名字列表。

约翰、山姆、彼得、杰克

我想用上面的每一个作为过滤器查询相同的 sql。每个查询都会给我一个唯一的员工 ID，我想用它来删除其他一些记录。

select emp_id from employee where emp_name like '%john%';

假设对于第一个查询，我得到的 id 为 1001。所以删除查询将如下所示。

delete from account_details where emp_id = 1001;
delete from hr_details where emp_id = 1001;
delete from pay_role_details where emp_id = 1001;

我必须为员工列表重复此操作。伪代码如下所示。

var emp_list = ['john', 'jack', 'kate', 'peter', 'sam',...]

for each :employee_name in emp_list
    select emp_id as :var_emp_id from employee where emp_name like '%:employee_name%'; 

    delete from account_details where emp_id = :var_emp_id;
    delete from hr_details where emp_id = :var_emp_id;
    delete from pay_role_details where emp_id = :var_emp_id;
end loop

我想要一个 PL-SQL 查询来执行此操作。请帮忙。谢谢。

我尝试的是如下所示。

set serveroutput on;
begin
loop x in ('john','jack', 'kate') loop as :name
  select emp_id as var_emp_id from employee where emp_name like '%:name%';
  // delete queries  
end loop;
end;

附：虽然根据提问，like query可能会产生多条记录，但在实际场景中，保证只有一条记录。为什么我使用 like 是在实际场景中，它是参考编号列表而不是名称。参考号还有一些其他的前置文本和后置文本，而我的逗号分隔列表只有数字。

Answer 1

也许以下会有所帮助：

BEGIN
  FOR aName IN (SELECT 'john'  AS EMP_NAME FROM DUAL
                UNION ALL
                SELECT 'sam'   AS EMP_NAME FROM DUAL
                UNION ALL
                SELECT 'peter' AS EMP_NAME FROM DUAL
                UNION ALL
                SELECT 'jack'  AS EMP_NAME FROM DUAL)
  LOOP
    FOR emp IN (SELECT * FROM EMPLOYEE WHERE EMP_NAME LIKE '%' || aName.EMP_NAME || '%')
    LOOP
      DELETE FROM ACCOUNT_DETAILS a WHERE a.EMP_ID = emp.EMP_ID;
      DELETE FROM HR_DETAILS h WHERE h.EMP_ID = emp.EMP_ID;
      DELETE FROM PAY_ROLE_DETAILS p WHERE p.EMP_ID = emp.EMP_ID;

      DBMS_OUTPUT.PUT_LINE('Deleted data for employee with EMP_ID=' || emp.EMP_ID);
    END LOOP;  -- emp
  END LOOP; -- aName
END;

研究此内容，直到您了解它的工作原理和原因。

分享和享受。

Answer 2

你真的需要一个光标来这样做吗？如果可能，请尝试跳过光标，以避免在大量数据上造成性能/内存使用不佳。

delete from account_details inner join employee on account_details.emp_id = employee.emp_id where WHERE CONTAINS(employee.emp_name, '"John" OR "Sam" OR "Max"', 1) >0;

delete from hr_details inner join employee on hr_details.emp_id = employee.emp_id where WHERE CONTAINS(employee.emp_name, '"John" OR "Sam" OR "Max"', 1) >0;

delete from pay_role_details inner join employee on pay_role_details.emp_id = employee.emp_id where WHERE CONTAINS(employee.emp_name, '"John" OR "Sam" OR "Max"', 1) >0;

Answer 3

使用 PL/SQL 游标选择您要删除的所有 ID，然后将其循环并在每次传递时发出 DELETE 语句。

可以在此处找到有关光标的详细信息：http://www.oracle.com/technetwork/issue-archive/2013/13-mar/o23plsql-1906474.html

动态 SQL 见这里：http://docs.oracle.com/cd/E11882_01/appdev.112/e25519/dynamic.htm#LNPLS627

代码示例：

    PROCEDURE delete_stuff
    IS

    id AS NUMBER;

    CURSOR your_cursor IS
    SELECT emp_id FROM employee WHERE CONTAINS(employee.emp_name, '"John" OR "Sam" OR "Max"', 1) > 0;

    OPEN your_cursor;
        LOOP
        FETCH your_cursor INTO id;
        EXIT WHEN your_cursor%NOTFOUND;

        EXECUTE IMMEDIATE 'DELETE FROM account_details WHERE emp_id = :id' USING id;
        EXECUTE IMMEDIATE 'DELETE FROM hr_details WHERE emp_id = :id' USING id;
        EXECUTE IMMEDIATE 'DELETE FROM pay_role_details WHERE emp_id = :id' USING id;

    CLOSE your_cursor;
    END LOOP;

    EXCEPTION 
    WHEN OTHERS THEN NULL;


END delete_stuff;