Question

当我加入两个表时，我对如何构建SQL查询感到困惑，以便我以后可以将它们绑定到gridview。

基本上我有两张桌子，

tablename: family
 __________________________
|Status |lastName|firstName|
|-------|--------|---------|
|1      |11      |111      |
|2      |22      |222      |
|3      |33      |333      |
''''''''''''''''''''''''''''
            +

tablename: familyStatus
 _____________________
|id        | Notes    |
|----------|----------|
|1         | 1111     |
|2         | 2222     |
|3         | 3333     |
'''''''''''''''''''''''

           =

Joined-tables: family+familyStatus [this is what i want]
 ____________________________
|firstName | lastName |Notes |
|----------|----------|------|
|111       | 11       |1111  |
|222       | 22       |2222  |
|333       | 33       |3333  |
''''''''''''''''''''''''''''''

您在此处看到的是 familyStatus 表中系列的状态和 id 是同一个键，status和id将隐藏在gridview上。

Lets just assume for now that this is how i get the family table.

SELECT Status, firstName, lastName
FROM family
WHERE firstName= @fN
AND lastName = @lN

我需要在此添加什么才能使来自族表的Notes也加入？

Answer 1

加入：

SELECT F.firstName, F.lastName, FS.Notes
FROM family F
INNER JOIN familyStatus FS
    ON F.[Status] = FS.id
WHERE F.firstName= @fN
AND F.lastName = @lN

Answer 2

将Status外键添加到familyStatus表并尝试以下操作：

SELECT firstName, lastName, Notes
FROM family JOIN familyStatus
ON family.Status =  familyStatus.Status
WHERE firstName= @fN
AND lastName = @lN

连接两个表以绑定在gridview上

2 个答案: