vb.net - 如何将sql查询值存储到数组中

Question

Dim sql As String = "Select ProductID From OrderDetail Order By ProductID Desc"
    Dim command As New SqlCommand(sql, connection)
    Dim reader1 As SqlDataReader = command.ExecuteReader()

如何将我检索到的所有 productid 存储到数组中？

Answer 1

Dim list As New List(Of Integer)

Using reader As SqlDataReader = command .ExecuteReader()
    While reader.Read()
        list.Add(reader.GetInt32(reader.GetOrdinal("ProductID")))
    End While
End Using
'check  list.ToArray() now

编辑：但是，我不会返回一个数组，而是返回一个通用整数列表（如果您只想返回 ProductId）或ProductClass对象列表

Private Function GetProductIDs() As IList(Of Integer)

    Dim list As New List(Of Integer)
    Dim conStr = "write your connection string here"

    Using connection As New SqlConnection(conStr )
        Dim sql As String = "Select ProductID From OrderDetail Order By ProductID Desc"
        Dim command As New SqlCommand(sql, connection)
        Using reader As SqlDataReader = command.ExecuteReader()
            While reader.Read()
                list.Add(reader.GetInt32(reader.GetOrdinal("ProductID")))
            End While
        End Using
    End Using

    Return list

End Function

编辑 2：根据评论， 要检索放入标签的文本，您可以这样做

Dim str As String
str = String.Join(",", GetProductIDs())
Label1.Text=str;

假设Label1是您的标签控件的ID。String.Join该方法将返回一个由逗号分隔的ProductId字符串，例如"1,2,6,7"

Answer 2

SQLdr = SQLCmd.ExecuteReader 'Gets Data

While dr.Read() 'While Data is Present        
      MsgBox(dr("Column Name")) 'Show data in a Message Box
End While

Loop While SQLdr.NextResult() 'Move to the Next Record

http://www.daniweb.com/software-development/vbnet/code/216920/sql-in-vb.net