Question

我是mysql和vb.net的新手并且有这个查询：

select `db_employee`.`firstName` as `firstName`, `db_employee`.`lastName` as `lastName`,
       `tbl_employment`.`position` as `position`
  from (`db_employee` `db_employee`
  inner join `tbl_employment` `tbl_employment` on (`tbl_employment`.`ctrlID` = `db_employee`.`ctrlID`))
 where (`tbl_employment`.`companyName` like 'MES%')

我想转换它在这里使用：

Dim MySqlConn = New MySqlConnection
MySqlConn.ConnectionString = connStr
Dim SDA As New MySqlDataAdapter
Dim dbdataset As New DataTable
Dim bsource As New BindingSource
MySqlConn.Open()
Dim query As String
query = ?

Answer 1

你可以使用下面的代码来显示数据...我希望这就是你想要的......：）

Dim cn As SqlConn= New SqlConn("Connecting String")
    Dim cmd As sqlCommand
     Dim dr As sqlDataReader
cn.open()
cmd = New sqlCommand("select * from table or your query, cn)
            dr = cmd.ExecuteReader()
            dr.Read()
            textbox1.Text = dr(1).ToString()
cn.close()

Answer 2

您可以使用您正在使用的MySQL提供商执行此类操作。这将创建您的连接，命令和数据读取器并正确关闭和处理所有内容。如果需要DataTable实例，可以从DataReader加载它。

    Using conn As New MySql.Data.MySqlClient.MySqlConnection("YourConnectionString")
        conn.Open()

        Using cmd As MySql.Data.MySqlClient.MySqlCommand = conn.CreateCommand
            cmd.CommandText = "select db_employee.firstName as firstName, " & _
                                        "db_employee.lastName as lastName, " & _
                                        "tbl_employment.position as position " & _
                                        "from db_employee db_employee " & _
                                        "inner join tbl_employment tbl_employment on tbl_employment.ctrlID = db_employee.ctrlID " & _
                                        "where tbl_employment.companyName like 'MES%' "

            ' Get a data reader that you can loop over or load a data table with
            Dim dr As MySql.Data.MySqlClient.MySqlDataReader = cmd.ExecuteReader

            ' How to read with a DataReader
            While dr.Read
                ' Do something with this
                Dim lastName As String = dr("lastName")

            End While


        End Using

        conn.Close()
    End Using

转换mysql查询以在vb.net中使用

2 个答案: