mysql - 一行中有2个ID，另一行中有名字和姓氏。如何从其他表中接收名字

我猜自一个月以来，我一直在努力1次锻炼，希望您能帮助我。我尝试通过多种方式从，与表或联接表中进行子查询，但未收到正确的结果。

好。表1中的一行存储如下信息：


客户编号
名字
lastame
服务员编号


表2中的一行存储如下信息：


userID（客户端和服务员是用户）
名字
姓




我是SQL的新手，但是我看到的是：

WITH waiter AS(
  SELECT
   waiter_id,
   firstname,
   lastname
 FROM Table1
 JOIN Table2 ON Table1.waiter_id = Table2.user_id
 )
 SELECT
  client_id,
  firstname as Firstname_client,
  lastname as Lastname_client,
  waiter_id,
  waiter.firstname as Firstname_waiter,
  waiter.lastname as Lastname_waiter
 FROM Table1
 JOIN waiter ON Table1.waiter_id = waiter.waiter.id

如有任何线索，我将不胜感激！

最佳答案

您可以尝试此查询。只需使用别名和JOIN

测试DLL

CREATE TABLE Table1(
    client_id int,
    firstname varchar(50),
    lastname  varchar(50),
    waiter_id int
);
INSERT INTO Table1 values (1,'Andrew','x',5);
INSERT INTO Table1 values (2,'Chris','xx',6);
INSERT INTO Table1 values (3,'Anna','xxx',7);
INSERT INTO Table1 values (4,'Julia','xxxx',8);

CREATE TABLE Table2(
    user_id int,
    firstname varchar(50),
    lastname  varchar(50)
);

INSERT INTO Table2 values (1,'Andrew','x');
INSERT INTO Table2 values (2,'Chris','xx');
INSERT INTO Table2 values (3,'Anna','xxx');
INSERT INTO Table2 values (4,'Julia','xxxx');
INSERT INTO Table2 values (5,'Mat','xxxxx');
INSERT INTO Table2 values (6,'Kathy','xxxxxx');
INSERT INTO Table2 values (7,'Pual','xxxxxxx');
INSERT INTO Table2 values (8,'John','xxxxxxxx');

询问

SELECT t1.client_id ,
        t1.firstname AS Firstance_client,
        t1.lastname as Lastname_Client,
        t1.waiter_id,
        t2.firstname as  Firstname_waiter ,
        t2.lastname as Lastname_Waiter
FROM Table1 t1
inner join Table2 t2 on t1.waiter_id = t2.user_id

sqlfiddle

[结果]：

| client_id | Firstance_client | Lastname_Client | waiter_id | Firstname_waiter | Lastname_Waiter |
|-----------|------------------|-----------------|-----------|------------------|-----------------|
|         1 |           Andrew |               x |         5 |              Mat |           xxxxx |
|         2 |            Chris |              xx |         6 |            Kathy |          xxxxxx |
|         3 |             Anna |             xxx |         7 |             Pual |         xxxxxxx |
|         4 |            Julia |            xxxx |         8 |             John |        xxxxxxxx |

关于mysql - 一行中有2个ID，另一行中有名字和姓氏。如何从其他表中接收名字，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/51474591/