Question

我遇到SQL连接问题。

我有EMPLOYEE

的表格EmpID, FirstName, LastName, Email, Phone

我有另一张表OTHERNAME，其中包含2个字段"Name" & "OtherName"。

此表包含查询值，例如"James", "Jim"; "Thomas", "Tom"; "Steven", "Steve"。

我想编写一个返回行的查询

EmpID, FirstName, LastName, Email, Phone, OtherName
where Employee.Firstname = OTHERName.Name

Answer 1

Select e.EmpID, e.FirstName, e.LastName, e.Email, e.Phone, o.OtherName
From Employee e
Left Outer Join OtherName o on e.FirstName = o.Name

从您的评论中，您实际上想要一个外部联接。

（来自评论）外部联接将返回所有员工，如果有其他名称则返回其他名称，否则其他名称将是您可以在代码中处理的空值。内部联接将结果限制为仅具有匹配记录的员工。

Answer 2

试试这个：

SELECT
    e.EmpID
        CASE 
            WHEN o.OtherName IS NOT NULL THEN OtherName
            ELSE e.FirstName
        END AS FirstName
        ,e.LastName
        ,e.Email
        ,e.Phone
        ,o.OtherName
    FROM Employee             e
    LEFT OUTER JOIN OtherName o ON e.FirstName = o.Name

Answer 3

select e.EmpID, e.FirstName, e.LastName, e.Email, e.Phone, o.OtherName 
from employee e,othername o 
where e.FirstName=o.name

Answer 4

SELECT E.EmpID, E.FirstName, E.LastName, E.Email, E.Phone, O.OtherName
FROM Employee E 
    INNER JOIN Othername O
        ON E.Firstname = O.Name

应该做的伎俩

或者，如果您想要所有结果，即使是那些没有“其他名称”值的结果。

SELECT E.EmpID, E.FirstName, E.LastName, E.Email, E.Phone, O.OtherName
FROM Employee E 
    LEFT OUTER JOIN Othername O
        ON E.Firstname = O.Name

Answer 5

SELECT E.EmpId， E.FirstName， E.LastName， E.Email， E.Phone， O.OtherName 来自EMPLOYEE E. INNER JOIN OTHERNAME O. ON E.FirstName = O.Name

Answer 6

您可以使用以下SQL命令

SELECT EMPLOYEE.EmpID, 
       EMPLOYEE.FirstName, 
       EMPLOYEE.LastName, 
       EMPLOYEE.Email, 
       EMPLOYEE.Phone, 
       OTHERNAME.OtherName FROM EMPLOYEE INNER JOIN OTHERNAME ON EMPLOYEE.FirstName = OTHERNAME.Name

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6 个答案: