VB.NET,带有 MySQL 的 Winforms 应用程序。在我的应用程序中,由于资金和连接可靠性的限制,我添加了通过使用邮件附件来更新它的功能。一切正常。在应用程序表单加载中,即使我让它检查文件是否存在。如果存在,则需要对数据库进行更改。因此,调用下面的 Sub 并将该文件的内容读入 arrayList ...当应用程序从 VS 外部启动时,我收到“CommandText 属性未正确初始化”错误。
Private Sub sqlUpdate(ByVal sqlScriptName As String)
Dim D As Boolean = BackupDatabase("C:\xxxxxxxx\temp.sql")
Dim objReader As New StreamReader(sqlScriptName)
Dim sLine As String = ""
Dim arrText As New ArrayList()
Do
sLine = objReader.ReadLine()
If Not sLine Is Nothing Then
arrText.Add(sLine)
End If
Loop Until sLine Is Nothing
objReader.Close()
For Each sLine In arrText
Dim conn As New MySqlConnection
Dim myCommand As New MySqlCommand
Dim connString As String = My.Settings.storageConnectionString
conn.ConnectionString = connString
myCommand.Connection = conn
myCommand.CommandText = String.Empty
Try
myCommand.CommandText = sLine
conn.Open()
myCommand.ExecuteNonQuery()
Catch myerror As MySqlException
'MsgBox("There was an error updating the database: " & myerror.Message + vbNewLine + "PLEASE CONTACT THE DEVELOPER IMMEDIATELY")
End Try
Next
Return
End Sub
不确定问题出在哪里,并且一直跟踪执行... sList 包含如下所示的有效 MYSQL 命令:
ALTER TABLE `storage`.`property_info` ADD COLUMN `pfam_pName` CHAR(200) NULL AFTER `pfam_Phone` ;
有什么想法可以让我朝着正确的方向前进???