Question

DataGridView1.DataSource = Nothing
        Dim con As New MySqlConnection("Data Source=localhost;user id=root; password=; database=ugibl;")
        Dim da As MySqlDataAdapter = Nothing

        Dim dt As New DataTable
        Dim SQL As String = ""
        Try
            **SQL = "select * FROM duty where '" & ComboBox3.Text & "' = '" & TextBox15.Text & "' "**
            con.Open()
            da = New MySqlDataAdapter(SQL, con)
            da.Fill(dt)
            con.Close()
            DataGridView1.DataSource = dt
        Catch ex As Exception
            If con.State = ConnectionState.Open Then
                con.Close()
            End If
        End Try
    End Subere

Answer 1

在列名称周围的MySql中使用的字符是反引号（ ALT + 096 ）而不是单引号。所以你创建sql命令的行是错误的。

SQL = "select * FROM duty where `" & ComboBox3.Text & "` = ....

但请记住，您不应该使用参数来构建连接字符串的sql命令。在您的情况下，该参数应该用于表示where语句中的值

...
SQL = "select * FROM duty where `" & ComboBox3.Text & "` = @param1"
con.Open()
da = New MySqlDataAdapter(SQL, con)
da.SelectCommand.Parameters.Add("@param1", MySqlDbType.VarChar).Value =  TextBox15.Text
da.Fill(dt)
....

请注意，您不能将参数用于列名称，只能将它们用于值

您好，我有一个带有sql数据库的vb.net应用程序我想搜索数据库并使用comboBox和textBox过滤搜索

1 个答案: