[英]Getting error in VB.Net when using INNER JOIN with insert and update together
[英]Inner Join in VB.Net
#Region "FillListView"
Sub FillListview()
LV.Items.Clear()
myqry = "SELECT AccResult.StudNo,Exercises.ID from AccResult INNER JOIN Exercises ON AccResult.StudNo = Exercises.ID ORDER BY AccResult.FirstName,AccResult.YrandSec Asc;"
mycmd = New OleDbCommand(myqry, con)
con.Open()
mydr = mycmd.ExecuteReader
While mydr.Read
With LV
.Items.Add(mydr("StudNo"))
With .Items(.Items.Count - 1).SubItems
.Add(mydr("CNumber"))
.Add(mydr("FirstName"))
.Add(mydr("LastName"))
.Add(mydr("YrandSec"))
.Add(mydr("Exer1"))
.Add(mydr("Exer2"))
.Add(mydr("Exer3"))
.Add(mydr("Exer4"))
.Add(mydr("Exer5"))
End With
End With
End While
con.Close()
End Sub
#End Region
AccResult
是我的第一個表的名稱,而Exercises
是第二個。 我的AccResult
PK是StudNo
,而Exercises
是ID
。 如何將這兩個表連接到ListView
?
AccResult
表:
StudNo (PK)
CNumber
FirstName
LastName
YrandSec
Exercises
表:
ID (PK)
StudNo
Exer1
Exer2
Exer3
Exer4
Exer5
您的JOIN條件不正確。
AccResult INNER JOIN Exercises ON AccResult.StudNo = Exercises.ID
正在使用子表的主鍵(Exercises.ID)加入父表(AccResult.StudNo)的主鍵。 您需要將父表(AccResult.StudNo)的主鍵與子表的外鍵 (Exercises.StudNo)連接,即,
AccResult INNER JOIN Exercises ON AccResult.StudNo = Exercises.StudNo
不確定我是否正確地得到了問題,但看起來查詢只選擇列:
myqry = "SELECT AccResult.StudNo,Exercises.ID from AccResult..."
然后代碼嘗試顯示所有列。 嘗試選擇所有列:
myqry = "SELECT * from AccResult..."
嘗試這個:
myqry = "SELECT AccResult.StudNo,Exercises.ID, Exer1, Exer2, Exer3, Exer4, Exer5 from AccResult INNER JOIN Exercises ON AccResult.StudNo = Exercises.ID ORDER BY AccResult.FirstName,AccResult.YrandSec Asc;"
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