例如,我目前有3個表中的行與0,1和3。主鍵,我希望它填補了國內空白,所以接下來的INSERT語句應採取主鍵爲2.但是,它並沒有這樣做。插入語句不插入使用正確的自動增量
Private Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click
Dim msg As String = ""
If Validate.CheckAddress(txtAddress.Text) And _
Validate.CheckEmailAddress(txtEmailAddress.Text) And _
Validate.CheckPhoneNumber(txtPhoneNumber.Text) And _
Validate.CheckPostcode(txtPostcode.Text) Then
MsgBox("correct validation")
Dim Admin As Integer = 0
Dim Query As String
If chkAdmin.Checked Then
Admin = 1
Else
Admin = 0
End If
If Not frmLogin.User.DoesUserExist(CInt(lblUserIDValue.Text)) Then 'if user doesnt exist
Query = "INSERT INTO tbluser (Admin, UserForename, UserSurname, Username, Password, UserPhoneNumber, UserAddress, UserPostcode, UserEmailAddress) VALUES (@admin, @forename, @surname, @username, @password, @phonenumber, @address, @postcode, @emailaddress)"
MsgBox("we are inserting")
Else
Query = "UPDATE tbluser SET [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] WHERE [email protected]"
MsgBox("we are updating")
End If
Using Conn As New MySqlConnection(MySQL.ConnectionDetails)
Using Comm As New MySqlCommand()
With Comm
.Connection = Conn
.CommandText = Query
.CommandType = CommandType.Text
.Parameters.AddWithValue("@admin", Admin)
.Parameters.AddWithValue("@forename", txtForename.Text)
.Parameters.AddWithValue("@surname", txtSurname.Text)
.Parameters.AddWithValue("@username", (txtForename.Text + txtSurname.Text.First + txtPhoneNumber.Text.Last.ToString)) 'firstname + first letter of surname + last number of phone number
.Parameters.AddWithValue("@password", "password")
.Parameters.AddWithValue("@phonenumber", txtPhoneNumber.Text)
.Parameters.AddWithValue("@address", txtAddress.Text)
.Parameters.AddWithValue("@postcode", txtPostcode.Text)
.Parameters.AddWithValue("@emailaddress", txtEmailAddress.Text)
.Parameters.AddWithValue("@userID", CInt(lblUserIDValue.Text))
End With
Try
Conn.Open()
If Comm.ExecuteNonQuery() Then
MsgBox("Successfull ")
Me.Dispose()
End If
Catch ex As MySqlException
msg += "MySQL Exception " & ex.GetBaseException.ToString
End Try
End Using
End Using
Else
If (Validate.CheckAddress(txtAddress.Text) = False) Then
msg += "Not a valid address " & Environment.NewLine
End If
If (Validate.CheckEmailAddress(txtEmailAddress.Text) = False) Then
msg += "Not a valid email address " & Environment.NewLine
End If
If (Validate.CheckPhoneNumber(txtPhoneNumber.Text) = False) Then
msg += "Not a valid phone number " & Environment.NewLine
End If
If (Validate.CheckPostcode(txtPostcode.Text) = False) Then
msg += "Not a valid postcode "
End If
End If
If (msg <> "") Then
MessageBox.Show("The following problems were found: " & Environment.NewLine & msg, "User - Error(s)", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
End If
End Sub
主鍵的意思是唯一的,不連續的截斷你的表。如果定義ID作爲自動增量數據庫會爲您創建一個(其工作的一部分,多數民衆贊成!)這意味着你沒有在SQL INSERT語句中指定它 – Plutonix
@Plutonix我已經設置了ID爲自動增量 – Man16
解決您的問題,長您需要創建子系統,在子系統中定期關閉[生產]小時將運行一個過程,該過程將枚舉所有密鑰並將所有「間隙」密鑰寫入單獨的表中。然後,在你的'Insert'邏輯中,你將嘗試保留一個間隙數字並將它用作PK,而你需要禁用自動增量。當沒有可用的間隙號碼時,您將像平常一樣繼續插入。但是你爲什麼要這麼麻煩呢?你會得到什麼?這值得麼? –