Solved

Consuming a C# Web Service’s ADO.NET Dataset in Delphi

Posted on 2004-09-30
5
969 Views
Last Modified: 2010-04-05
I am trying to consume with Delphi an ADO.NET dataset provided by a C# web service. I seem to running into trouble when it comes to having Delphi’s XMLMapper take the XML from the c# web service and map the transformation out properly, it is only returning the column headers, with no data… I am posting the code to the web service.

[WebMethod]
public DataSet GetDS(string sInput)
{
      ds = new DataSet();

      oOracleConn = new OracleConnection();

      sSQL = string.format("select * from table where table.input = {0}", sInput); \\ I simplified this

      oOracleConn.ConnectionString = "User Id=****;Password=********;Data Source=****";

      oDataAdapter = new OracleDataAdapter(sSQL, oOracleConn);

      oOracleConn.Open();
      oDataAdapter.Fill(ds);
      oOracleConn.Close();

      return ds;
}

Please let me know if there are alternatives to this method, along with source code. The end result is for a C# Web Service ADO.NET dataset to be consumed by Delphi 7 and displayed in a data grid. I was not sure where to post this question, so I posted it in C# and Delphi, and whoever can answer my question first, can have points for both posts.

Regards,

Joel
0
Comment
Question by:j_oller
  • 3
  • 2
5 Comments
 
LVL 6

Accepted Solution

by:
bpana earned 500 total points
ID: 12198715
I think I have already answered a similar question. take a look here:
http://www.experts-exchange.com/Programming/Programming_Languages/Delphi/Q_21046672.html

Bogdan
0
 

Author Comment

by:j_oller
ID: 12201707
Thanks Bogdan,

If my C# web service pushed XML out like the XML on your post, I would not have a problem. I will paste a little more code to illustrate my problem.

C# Webservice:

            [WebMethod]
            public DataSet GetDS2()
            {
          DataTable dt = new DataTable();
            dt.Columns.Add("ID", System.Type.GetType("System.Int32"));
          dt.Columns.Add("Data", System.Type.GetType("System.String"));
            dt.Columns.Add("CreateDate", System.Type.GetType("System.DateTime"));

            DataRow dr;

            dr = dt.NewRow();
            dr["ID"] = 1;
            dr["Data"] = "First Row";
            dr["CreateDate"] = System.DateTime.Now;
          dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr["ID"] = 2;
            dr["Data"] = "Second Row";
            dr["CreateDate"] = System.DateTime.Now;
            dt.Rows.Add(dr);

            DataSet ds2 = new DataSet("SampleDataSet");
            ds2.Tables.Add(dt);
            return ds2;
            }

Pushes this XML, which Delphi's XML Mapper will not map with dataset:

<?xml version="1.0" encoding="utf-8"?>
<DataSet xmlns="http://tempuri.org/">
  <xs:schema id="SampleDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
    <xs:element name="SampleDataSet" msdata:IsDataSet="true">
      <xs:complexType>
        <xs:choice maxOccurs="unbounded">
          <xs:element name="Table1">
            <xs:complexType>
              <xs:sequence>
                <xs:element name="ID" type="xs:int" minOccurs="0" />
                <xs:element name="Data" type="xs:string" minOccurs="0" />
                <xs:element name="CreateDate" type="xs:dateTime" minOccurs="0" />
              </xs:sequence>
            </xs:complexType>
          </xs:element>
        </xs:choice>
      </xs:complexType>
    </xs:element>
  </xs:schema>
  <diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1">
    <SampleDataSet xmlns="">
      <Table1 diffgr:id="Table11" msdata:rowOrder="0" diffgr:hasChanges="inserted">
        <ID>1</ID>
        <Data>First Row</Data>
        <CreateDate>2004-10-01T09:07:03.9186134-07:00</CreateDate>
      </Table1>
      <Table1 diffgr:id="Table12" msdata:rowOrder="1" diffgr:hasChanges="inserted">
        <ID>2</ID>
        <Data>Second Row</Data>
        <CreateDate>2004-10-01T09:07:03.9186134-07:00</CreateDate>
      </Table1>
    </SampleDataSet>
  </diffgr:diffgram>
</DataSet>

The XML needs to look like this instead (I got this from C# Windows Application -> ds2.WriteXml("c:\\output.xml")):

<?xml version="1.0" standalone="yes"?>
<SampleDataSet>
  <Table1>
    <ID>1</ID>
    <Data>First Row</Data>
    <CreateDate>2004-10-01T09:15:12.1248693-07:00</CreateDate>
  </Table1>
  <Table1>
    <ID>2</ID>
    <Data>Second Row</Data>
    <CreateDate>2004-10-01T09:15:12.1248693-07:00</CreateDate>
  </Table1>
</SampleDataSet>

Thanks,

Joel
0
 

Author Comment

by:j_oller
ID: 12204985
I got it figured out, I will post the code when I can.

Regards,

Joel
0
 

Author Comment

by:j_oller
ID: 12218673
Before: I was returning a Dataset document, which most other applications dont know how to handle
Now: I have changed my code to return a plain XML Document, and then converted my dataset to xml, and served it through the webservice

There may be better ways of doing it, but this is what I have come up with.

[WebMethod]
          public System.Xml.XmlDocument getDS2()
          {
               DataTable dt = new DataTable();
               DataSet ds2 = new DataSet("SampleDataSet");

               dt.Columns.Add("ID", System.Type.GetType("System.Int32"));
               dt.Columns.Add("Data", System.Type.GetType("System.String"));
               dt.Columns.Add("CreateDate", System.Type.GetType("System.DateTime"));

               DataRow dr;

               dr = dt.NewRow();
               dr["ID"] = 1;
               dr["Data"] = "First Row";
               dr["CreateDate"] = System.DateTime.Now;
               dt.Rows.Add(dr);

               dr = dt.NewRow();
               dr["ID"] = 2;
               dr["Data"] = "Second Row";
               dr["CreateDate"] = System.DateTime.Now;
               dt.Rows.Add(dr);

               ds2.Tables.Add(dt);
         
               System.IO.StringWriter sw = new System.IO.StringWriter();
               ds2.Namespace="";
               ds2.WriteXml(sw);
               System.Xml.XmlDocument xDoc = new System.Xml.XmlDocument();
               xDoc.LoadXml(sw.ToString());
               return xDoc;
          }

Thanks,

Joel
0
 
LVL 6

Expert Comment

by:bpana
ID: 12224377
Hi, Joel.

I have used webservices in the same way (exporting data as xml).

Bogdan
0

Featured Post

Does Powershell have you tied up in knots?

Managing Active Directory does not always have to be complicated.  If you are spending more time trying instead of doing, then it's time to look at something else. For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why

Question has a verified solution.

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

Have you ever had your Delphi form/application just hanging while waiting for data to load? This is the article to read if you want to learn some things about adding threads for data loading in the background. First, I'll setup a general applica…
Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
Microsoft Active Directory, the widely used IT infrastructure, is known for its high risk of credential theft. The best way to test your Active Directory’s vulnerabilities to pass-the-ticket, pass-the-hash, privilege escalation, and malware attacks …

832 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