我想从sqlserver中获取字母数字的最大值/最小值 [英] I want to fetch alphanumeric max/min value from sqlserver

问题描述

Protected Sub btnFirst_Click(ByVal sender As Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles btnFirst.Click
      Dim i As Long = 0

      Dim str1 As String = "SELECT Min(IT_CODE_ACT) FROM PS_EXT_MAST "

      conn.Open()
      Dim cmd1 As SqlCommand = New SqlCommand(str1, conn)
      Dim dr As SqlDataReader = cmd1.ExecuteReader()

      dr.Read()
      If dr.HasRows Then
          txtItemCode.Text = dr(0).ToString()
          i = Convert.ToInt32(txtItemCode.Text)
      End If
      conn.Close()

      Dim str2 As String = "select IT_DESC from PS_EXT_MAST where IT_CODE_ACT= " + i
      conn.Open()
      Dim cmd2 As SqlCommand = New SqlCommand(str2, conn)
      Dim dr2 As SqlDataReader = cmd2.ExecuteReader()
      dr2.Read()

      If dr2.HasRows Then
          txtItemDesc.Text = dr2(0).ToString()

      End If
      conn.Close()

      Response.Write("<Script>alert(' First record found....')</Script>")
  End Sub

  Protected Sub btnLast_Click(ByVal sender As Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles btnLast.Click
      Dim i As Long = 0

      Dim str1 As String = "SELECT Max(IT_CODE_ACT) FROM PS_EXT_MAST"
      conn.Open()
      Dim cmd1 As SqlCommand = New SqlCommand(str1, conn)
      Dim dr As SqlDataReader = cmd1.ExecuteReader()

      dr.Read()
      If dr.HasRows Then
          txtItemCode.Text = dr(0).ToString()
          i = Convert.ToInt32(txtItemCode.Text)
      End If
      conn.Close()

      Dim str2 As String = "select IT_DESC from PS_EXT_MAST where IT_CODE_ACT=" + i
      conn.Open()
      Dim cmd2 As SqlCommand = New SqlCommand(str2, conn)
      Dim dr2 As SqlDataReader = cmd2.ExecuteReader()
      dr2.Read()
      If dr2.HasRows Then
          txtItemDesc.Text = dr2(0).ToString()
      End If
      conn.Close()

      Response.Write("<Script>alert(' Last record found....')</Script>")
  End Sub

***我想从sqlserver中获取字母数字的最大值/最小值

***I want to fetch alphanumeric max/min value from sqlserver
error is occured, what will be my query?

推荐答案

您首先需要定义最小/最大字母数字值，因为对于数字来说这是清楚的，但对于字母数字而言值不是.如果按照A-z的方式表示最小/最大，则可以在该特定字段上排序，并获取集合中的第一条和最后一条记录.

旁注:像这样使用sql进行编码的方式存在安全隐患，等待发生.至少看看sql参数.

祝您好运！

You would first need to define what a min/max alphanumeric value is because for numbers this is clear but for alphanumeric values it isn''t. If you mean min/max as in A-z, you could sort on that specific field and take the first and last record in the set.

Sidenote: The way you code using sql like this is a security hazard waiting to happen. At least have a look at sql parameters.

Good luck!

为此，您可以像使用
那样使用按升序和降序排序的Aggregate函数排序 从表1中选择名称，顺序为(名称)十进制/升序.
希望对您有帮助

For this you can use order by Aggregate function with Ascending and descending like
select name from table1 order by(name) decs / Asc.
i hope this give some help you

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