2016-01-22 36 views
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大家好我是这个网站的新手,我想要你们的帮助。我目前正在研究我使用的是VB.net 2010的项目。我需要有关可以自动生成的ID的帮助。VB.Net中自动生成的字母数字ID

我希望我的ID是这样的: CAT001 CAT002 CAT003 等。

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显示我们到目前为止你已经尝试过什么,在哪里你有一个问题/错误。 –

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con.Open() cmd.Connection = CON cmd.CommandText = “SELECT COUNT(book_id)FROM tbl_book” 昏暗intCount = cmd.ExecuteScalar() txtCatID.Text = intCount.ToString()+ 1 CON。关闭()这是我试过的代码,它的工作唯一的问题是只有数字会出现,我不知道如何添加我想要的字符是CAT001,CAT002等。 – Laxus

回答

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假设你有某种计数器称为_idNumber的ID号,然后你可以有这样的:

Dim idString as String = String.Format("CAT{0}", _idNumber.ToString("D3")) 
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Private Sub autogenerate_ID() 
    Dim mysqlconnection As MySqlConnection 
    Dim command As New MySqlCommand 

    MySqlConnection = New MySqlConnection() 
    MySqlConnection.ConnectionString = " server = localhost; user id = root; password=; database = your database " 
    Command.Connection = MySqlConnection 
    mysqlconnection.Open() 

    Dim sqlquery = "select Max(ID) from yourtable " 
    command.CommandText = sqlquery 
    Dim ID As Integer 
    Dim value As String 

    value = command.ExecuteScalar().ToString() 

    If String.IsNullOrEmpty(value) Then 
     value = "CAT000" 
    End If 

    value = value.Substring(3) 
    Int32.TryParse(value, ID) 
    ID = ID + 1 
    value = "CAT" + ID.ToString("D3") 
    Txt.Text = value 

    command.Dispose() 
    mysqlconnection.Close() 
    mysqlconnection.Dispose() 

End Sub