Question

员工

ID    Name   
1     John
2     Williams

预约

ID  DoctorName   Employee_id  Team lead
1    willson          1            2

SQL

SELECT E.*,A.* FROM Employee as E,Appointment as A WHERE A.Employee_id = E.ID

如果我想要获取团队负责人名称我们如何做到这一点，这是我的加入？

Answer 1

试试这个：

SELECT A.ID,A.DoctorName,E.Name as Employee,E1.Name as TeamLead
FROM Appointment A INNER JOIN
Employee E ON E.ID=A.Employee_id INNER JOIN
Employee E1 ON E1.ID=A.TeamLead

结果将是：

ID  DoctorName  Employee_id   TeamLead
---------------------------------------
1   willson     John          Williams

请参阅SQL Fiddle中的结果。

修改

要包含更多表，您需要使用不同的别名加入Employee表：

SELECT A.ID,A.DoctorName,E.Name as Employee,E1.Name as TeamLead,E2.Name as AttendedBy, Att.Attended FROM Appointment A INNER JOIN tblAttended Att ON Att.Id=A.Id INNER JOIN Employee E ON E.ID=A.Employee_id INNER JOIN Employee E1 ON E1.ID=A.TeamLead INNER JOIN Employee E2 ON E2.ID=Att.employee_id

示例结果：

ID DoctorName Employee_id TeamLead AttendedBy Attended ----------------------------------------------------------------- 1 willson John Williams John Y

Answer 2

试试这个

SELECT E.name
FROM Employee E
JOIN Appointment A 
ON A.Employee_id = E.ID
WHERE [some condition here]

Answer 3

试试这个：

SELECT A.ID,A.DoctorName,E.Name,E1.Name 
FROM Employee E
INNER JOIN Appointment A
ON A.Employee_id = A.ID
WHERE E1.ID=A.Teamlead

Answer 4

您还没有使用过加入。你需要在这里使用join。您的TeamLead必须与Employee id相同。基于此，您必须选择Employee名称，并将其别名为TeamLeadName。

SELECT A.ID, A.DoctorName, A.Employee_id, E.Name as TeamLeadName
FROM Appointment A
JOIN Employee E
ON A.TeamLead = E.ID

Answer 5

如果团队在预约表中领导姓名，请使用以下QUERY：

SELECT E.Name AS 'Employee Name',A.DoctorName AS 'Doctor', A.TeamLeadName AS 'Team Lead' FROM Employee AS E,Appointment AS A WHERE A.Employee_id = E.ID;

如果团队领导NAME IN的表格不同，那么TeamLead会在QUERY下方使用：

SELECT E.Name AS 'Employee Name',A.DoctorName AS 'Doctor', T.TeamLeadName AS 'Team Lead' FROM Employee AS E,Appointment AS A, TeamLead AS T WHERE A.Employee_id = E.ID AND A.TeamLead=T.TeamLead_ID;

如果Williams是teamlead（在您的问题中未提及），请使用以下查询：

SELECT E.Name AS 'Employee Name',A.DoctorName AS 'Doctor', T.Name AS 'Team Lead' FROM Employee AS E,Appointment AS A, Employee AS T WHERE A.Employee_id = E.ID AND A.TeamLead=T.ID;

从连接中具有多个ID的一个表中获取名称

5 个答案: