?
Solved

SqlDataReader doesn't Read() even though it HasRows

Posted on 2014-02-11
3
Medium Priority
?
414 Views
Last Modified: 2014-02-12
Hi Experts,

I'm building a javascript string from a code-behind page with data retrieved from a sql database.

The datareader has rows, but it doesn't read. If I build the string outside of the read loop, it works (but only retrieves the first line). What am I doing wrong?

THanks for your help

  Function sFnLoadCodingLines() As String
        Dim cmdCoding As SqlCommand, drCoding As SqlDataReader, con As New SqlConnection(strcon)
        Dim sTemp As String = ""
        Dim lInvoiceID As Long

        lInvoiceID = CLng(Page.Request.QueryString("InvoiceID"))

        cmdCoding = New SqlCommand
        cmdCoding.CommandText = "SELECT BU,DEPT,AccNo,Qty,Amount,Description,EMP,VARIETAL,BRAND,STATE,PROJECT FROM OI_tblCoding WHERE isDeleted=0 AND InvoiceID=" & lInvoiceID
        cmdCoding.Connection = con
        con.Open()
        drCoding = cmdCoding.ExecuteReader
        drCoding.Read()

        If drCoding.HasRows() Then

            While drCoding.Read()
                'addRowToTable(sBU, sDPT, sAcct, dbQty, dbAmt, sDesc, sEmp, sVar, sBrand, sState, sProj)
                sTemp = sTemp & "addRowToTable(""" & drCoding("BU").ToString & _
                                """,""" & drCoding("DEPT").ToString & _
                                """,""" & drCoding("AccNo").ToString & _
                                """,""" & drCoding("Qty").ToString & _
                                """,""" & drCoding("Amount").ToString & _
                                """,""" & drCoding("Description").ToString & _
                                """,""" & drCoding("EMP").ToString & _
                                """,""" & drCoding("VARIETAL").ToString & _
                                """,""" & drCoding("BRAND").ToString & _
                                """,""" & drCoding("STATE").ToString & _
                                """,""" & drCoding("PROJECT").ToString & """);" & vbCrLf

            End While

            sFnLoadCodingLines = sTemp

        Else
            sFnLoadCodingLines = ""
        End If

        con.Close()

    End Function

Open in new window

0
Comment
Question by:nutsch
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 40

Accepted Solution

by:
Jacques Bourgeois (James Burger) earned 1600 total points
ID: 39852175
You read the  first line before checking if the DataReader has rows, and you do nothing with the result of that Read,  so you lose it.

If your query return only one line, then While is skipped even if there are Rows, because the only one that was there was already Read.
0
 
LVL 14

Assisted Solution

by:dejaanbu
dejaanbu earned 400 total points
ID: 39853083
0
 
LVL 39

Author Closing Comment

by:nutsch
ID: 39853788
This is the doh! moment. I've tried to tweak that code so many times that I don't know if that line was there the whole time. Anyways, it works.

Thanks for pointing out the error of my ways,

Thomas
0

Featured Post

Moving data to the cloud? Find out if you’re ready

Before moving to the cloud, it is important to carefully define your db needs, plan for the migration & understand prod. environment. This wp explains how to define what you need from a cloud provider, plan for the migration & what putting a cloud solution into practice entails.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article explains how to reset the password of the sa account on a Microsoft SQL Server.  The steps in this article work in SQL 2005, 2008, 2008 R2, 2012, 2014 and 2016.
This article shows gives you an overview on SQL Server 2016 row level security. You will also get to know the usages of row-level-security and how it works
This video shows how to set up a shell script to accept a positional parameter when called, pass that to a SQL script, accept the output from the statement back and then manipulate it in the Shell.
Viewers will learn how to use the SELECT statement in SQL and will be exposed to the many uses the SELECT statement has.

718 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question