Question

我只是数据库基础的初学者，使用完此工具后，它仅显示msgbox并显示未知命令。

Try
    connectionDB.Open()
    cmdDB.CommandText = "SELECT * FROM rescuers WHERE LastName='" & searchres.Text & "';"
    readDB = cmdDB.ExecuteReader()
    With readDB
        .Read()
        rescid.Text = .Item("RescuerID")
        lname.Text = .Item("LastName")
        fname.Text = .Item("FirstName")



        .Close()
    End With

Answer 1

尝试像这样设置sqlcommand和sqldatareader：

    Dim command As New SqlCommand("SELECT * FROM rescuers WHERE LastName='" & searchres.Text & "'", connection)
    Dim reader As SqlDataReader = command.ExecuteReader()

也发布您的代码以设置SqlConnection。

Answer 2

尝试使用参数避免SQL注入

cmdDB = New SqlCommand("SELECT * FROM rescuers WHERE LastName = @LastName", DatabaseConnection)

cmdDB.Parameters.AddWithValue("@LastName", searchres.Text)

readDB = cmdDB.ExecuteReader()

这是假设您已经按照以下方式定义了您的阅读器：

Dim readDB As SqlDataReader

此代码有什么问题？我无法从数据库中检索数据

2 个答案: