Question

我有一个名为-g的表，它有2个外键：tbl_appointment和idclient，它们引用idemployee。所以我想做的不是获取tbl_persons id和idclient的{{1}}，而是希望获得属于那些idemployee的{{1}}名称

查询

(name,last_name,last_sname)

Answer 1

尝试以下

SELECT
  app.*,
  CONCAT(client.name,' ',client.last_name,' ',client.last_sname) AS client_full_name,
  CONCAT(empl.name,' ',empl.last_name,' ',empl.last_sname) AS empl_full_name
FROM tbl_appointment app
LEFT JOIN tbl_persons client ON app.idclient=client.id
LEFT JOIN tbl_persons empl ON app.idemployee=empl.id
WHERE app.idclient= '$user'

Answer 2

您可以使用LEFT JOIN代替<h1>Concatenation Challenge</h1> <table> <tr> <td>All days of the week</td> <td id="demo2"></td> </tr> </table>

来使用以下查询

INNER JOIN

Answer 3

尝试以下代码：只有你必须分别选择客户和员工，一起更难

SELECT name,last_name,last_sname 
    FROM tbl_persons WHERE id IN (
      SELECT DISTINCT idclient FROM tbl_appointment;
    ); -- This will select all the clients

SELECT name,last_name,last_sname 
FROM tbl_persons WHERE id IN (
  SELECT DISTINCT idemployee FROM tbl_appointment;
); -- This will select all the employees

SQL - 获取名称而不是ID

3 个答案: