Question

如果我只添加一个查询，例如hostnameQuery，则代码可以正常工作，因为您可以看到我尝试添加多个。

我尝试在MySqlCommand上使用+ and &但是我收到了语法错误。

Dim hostnameQuery As String = "SELECT `HOSTNAME` FROM `m1` WHERE 1"
    Dim osQuery As String = "SELECT `OS` FROM `m1` WHERE 1"
    Dim SQLConnection As New MySqlConnection(My.Settings.connStr)
    Dim cmd As New MySqlCommand(hostnameQuery & osQuery, SQLConnection)

    Try
        SQLConnection.Open()
        cmd.ExecuteNonQuery()
        Dim reader As MySqlDataReader
        reader = cmd.ExecuteReader
        While reader.Read
            main.Label64.Text = (reader.GetString(0))
            main.Label65.Text = (reader.GetString(0))
        End While
    Catch ex As Exception
        MsgBox(ex.Message.ToString)
    Finally
        SQLConnection.Close()

    End Try

Answer 1

尝试：

Dim hostnameQuery As String = "SELECT `HOSTNAME` FROM `m1` WHERE 1 UNION ALL (SELECT `OS` FROM `m1` WHERE 1)";

或者你为什么不（因为你查询1个表）：

 Dim hostnameQuery As String = "SELECT `HOSTNAME`,`OS`  FROM `m1` WHERE 1 ";

 .....

While reader.Read
            main.Label64.Text = (reader.GetString(0))
            main.Label65.Text = (reader.GetString(1))

多个MySQL查询

1 个答案: