mysql - 如何将下拉框中的值添加到 Mysql 查询中？

Question

我有一个下拉框，您可以在其中选择以下内容:

“今天”
“过去 7 天”

MySQL 查询是:

Dim x1 As New MySqlConnection("Server=localhost;Database=test;UID=test;PWD=test;")
x1.Open()
Dim comx1 As New MySqlCommand("SELECT COUNT(*) as c FROM toutcome WHERE AffID = '" & CType(Session.Item("affID"), String) & "' AND CompletedDate= '" & DropDownList1.Text & "'", x1)
Dim myReaderx1 As MySqlDataReader = comx1.ExecuteReader(CommandBehavior.CloseConnection)
myReaderx1.Read()
Label12.Text = myReaderx1.Item(0).ToString()

保管箱中今天的值应该是“CURDATE() ”

因此查询应该如下所示:

Dim x1 As New MySqlConnection("Server=localhost;Database=test;UID=test;PWD=test;")
x1.Open()
Dim comx1 As New MySqlCommand("SELECT COUNT(*) as c FROM toutcome WHERE AffID = '" & CType(Session.Item("affID"), String) & "' AND CompletedDate = CURDATE() ", x1)
Dim myReaderx1 As MySqlDataReader = comx1.ExecuteReader(CommandBehavior.CloseConnection)
myReaderx1.Read()
Label12.Text = myReaderx1.Item(0).ToString()

我该怎么做？
使用 Dropbox 中的值填充 DropDownList1.Text。

Answer 1

Dim commandText = "SELECT COUNT(*) as c FROM toutcome " & _
                 "WHERE AffID = '" & CType(Session.Item("affID"), String) & "' AND CompletedDate = @init "
        Using c = New MySqlConnection("Server=localhost;Database=test;UID=test;PWD=test;")
            Using com = New MySqlCommand(commandText, c)
                c.Open()
                com.Parameters.Add("@init", MySqlDbType.String).Value = Convert.ToString(DropDownList1.Text)
                Using myReader = com.ExecuteReader(CommandBehavior.CloseConnection)
                    If myReader.Read() Then
                        Label11.Text = myReader.Item(0).ToString()

                        myReader.Close()
                    End If
                End Using
            End Using
        End Using