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任何人都可以幫助我解決我的查詢。我想更新我的數據,如果syscode
不存在,但當我嘗試更新sysdesc
它失敗,因爲syscode
已經存在。如果不存在vb.net更新
Dim query As String
Dim rowsAffected As Integer
query = "UPDATE tbl_sysname SET syscode = @code, sysdesc = @desc " & _
"WHERE id = @id AND NOT EXISTS (SELECT syscode FROM tbl_sysname WHERE " & _
"syscode = @code) "
cmd = New SqlCommand(query, cn)
cmd.Parameters.Add("@code", SqlDbType.VarChar).Value = txtCode.Text
cmd.Parameters.Add("@desc", SqlDbType.VarChar).Value = txtDesc.Text
cmd.Parameters.Add("@id", SqlDbType.VarChar).Value = lblId.Text
rowsAffected = cmd.ExecuteNonQuery
'MsgBox(rowsAffected)
If rowsAffected >= 1 Then
'reader = cmd.ExecuteReader
MsgBox("Update Successfully")
LVSysName.Items.Clear()
'reader.Close()
GetLvData() 'This will display the data of LvSysName
Else
MsgBox("Failed to Update")
End If
我想避免在同一時間,我可以更新sysdesc
的syscode
重複。 幫我解決我的查詢或給我一個建議,我應該怎麼做
爲什麼'sysdesc'的更新受到'syscode'的影響? –
當我更新'sysdesc''rowsAffected'將返回0因爲'NOT EXIST'函數 –
沒問題,所以即使數據庫中存在'syscode',你想更新'sysdesc'? –