用多个表模拟 MySQL 中的交集并加入

Question

我需要在 MySQL 中模拟 Intersect 查询。

    SELECT c.cust_code, cust_fname, cust_lname  
      FROM lgcustomer c JOIN lginvoice i ON c.cust_code = i.cust_code 
      WHERE employee_id = 83649 
    INTERSECT 
    SELECT c.cust_code, cust_fname, cust_lname  
      FROM lgcustomer c JOIN lginvoice i ON c.cust_code = i.cust_code  
      WHERE employee_id = 83677 
    ORDER BY cust_lname, cust_fname;

我尝试过使用 EXISTS 但没有成功。我想我加入错了？

    SELECT C.CUST_CODE, CUST_FNAME, CUST_LNAME
      FROM LGCUSTOMER C JOIN LGINVOICE I ON C.CUST_CODE = I.CUST_CODE
      WHERE EMPLOYEE_ID = 83649
      AND EXISTS (SELECT * 
                 FROM LGCUSTOMER C JOIN LGINVOICE I ON C.CUST_CODE = I.CUST_CODE
                 WHERE EMPLOYEE_ID = 83677)
    ORDER BY CUST_LNAME, CUST_FNAME;

表格是：

+--------------+
|客户 |
+------------+
| Cust_code |
| Cust_Fname |
| Cust_Lname |
+------------+

和
+--------------+
| LGINVOICE |
+--------------+
| Cust_code |
| Employee_ID |
+----------------+

我需要一个查询来提取所有具有来自两个唯一员工（83649 和 83677）的发票的客户代码

Answer 1

嗯。 . .想到聚合：

SELECT c.cust_code, cust_fname, cust_lname  
FROM lgcustomer c JOIN
     lginvoice i
     ON c.cust_code = i.cust_code 
WHERE employee_id IN ( 83649, 83677 )
GROUP BY c.cust_code, cust_fname, cust_lname 
HAVING COUNT(DISTINCT employee_id) = 2;

与 INTERSECT 一样，这也删除了重复项。

Answer 2

您可以使用两个子查询之间的内部 joij 来模拟相交

select * from  (
  SELECT c.cust_code, cust_fname, cust_lname  
  FROM lgcustomer c 
  JOIN lginvoice i ON c.cust_code = i.cust_code 
  WHERE employee_id = 83649 
) t1 
INNER JOIN  (
  SELECT c.cust_code, cust_fname, cust_lname  
  FROM lgcustomer c 
  JOIN lginvoice i ON c.cust_code = i.cust_code  
  WHERE employee_id = 83677 
) t2 on t1.cust_code = t2.cust_code 
ORDER BY cust_lname, cust_fname;

用多个表模拟 MySQL 中的交集并加入

Emulate an Intersect in MySQL w/ multiple tables and Join

mysql

sql

intersect