Solved

Easy way to obtain new Autonumber ID Field from newly created row (ADO.Net in C#)

Posted on 2006-06-25
6
284 Views
Last Modified: 2011-04-14
Hi all,

I have the code below which adds a new record to my database and then updates it.  The database is Microsoft Access and i'm using the OleDbAdapters in ADO.Net with a disconnected dataset.  I want to grab the "ProjectID" field which is an Autonumber field that isn't created until you "update" the dataset.  Is there an easy way to get it without reopening the whole database and doing an SQL search for the record I just created using the Project Title?  Maybe some sort of "newid" method or some such?

Here is the code I have now:

OleDbDataAdapter daOurAdapter;
            DataSet dsResults;

            //do a search
            this.mstrSQL = "SELECT * FROM Projects";

            this.instantiateDatabase();

            try
            {
                //create an adapter to interact with the database
                daOurAdapter = new OleDbDataAdapter(this.mstrSQL, this.dbConnect);

                //make our dataset object an actual dataset
                dsResults = new DataSet();

                //now fill our dataset object with data (if any)
                daOurAdapter.Fill(dsResults, "Projects");

                //we now have a DataSet object that contains any results that have been returned by our query
                //create a DataTable object representing the table returned
                DataTable dtProjects = dsResults.Tables["Projects"];

                DataRow drProjectResults = dtProjects.NewRow();                
               
                drProjectResults["CustomerID"] = cboCustomers.SelectedValue;
                drProjectResults["ProjectTitle"] = (string)txtProjectTitle.Text;
                drProjectResults["ProjectNotes"] = (string)txtProjectNotes.Text;
                if (txtRender1Loc.Text != "")
                    drProjectResults["RenderLocation1"] = (string)txtRender1Loc.Text;
                if (txtRender1Desc.Text != "")
                    drProjectResults["RenderDescription1"] = (string)txtRender1Desc.Text;
                if (txtRender2Loc.Text != "")
                    drProjectResults["RenderLocation2"] = (string)txtRender2Loc.Text;
                if (txtRender2Desc.Text != "")
                    drProjectResults["RenderDescription2"] = (string)txtRender2Desc.Text;
                if (txtRender3Loc.Text != "")
                    drProjectResults["RenderLocation3"] = (string)txtRender3Loc.Text;
                if (txtRender3Desc.Text != "")
                    drProjectResults["RenderDescription3"] = (string)txtRender3Desc.Text;
                if (txtRender4Loc.Text != "")
                    drProjectResults["RenderLocation4"] = (string)txtRender4Loc.Text;
                if (txtRender4Desc.Text != "")
                    drProjectResults["RenderDescription4"] = (string)txtRender4Desc.Text;
                if (txtRender5Loc.Text != "")
                    drProjectResults["RenderLocation5"] = (string)txtRender5Loc.Text;
                if (txtRender5Desc.Text != "")
                    drProjectResults["RenderDescription5"] = (string)txtRender5Desc.Text;
                drProjectResults["Status"] = 0;
                drProjectResults["StartDate"] = (string)txtStartDate.Text;
                if (txtDueDate.Text != "")
                    drProjectResults["DueDate"] = (string)txtDueDate.Text;                

                //push all changes to the database
                dtProjects.Rows.Add(drProjectResults);



                //FIGURE OUT THE NEW PROJECT ID HERE AND CREATE THE DIRECTORY WITH THE CUSTOMER ID, THEN
                //CREATE A DIRECTORY WITH THE PROJECT ID

               // MessageBox.Show("New project id = " + drProjectResults["ProjectID"]);  <-- this doesn't work

                if (!dsResults.HasErrors)
                {
                    // Set up insert, update, and delete commands
                    OleDbCommandBuilder cmdBuilder = new OleDbCommandBuilder(daOurAdapter);

                    //setup escape characters
                    cmdBuilder.QuotePrefix = "[";
                    cmdBuilder.QuoteSuffix = "]";

                    daOurAdapter.Update(dsResults, "Projects");

                    dsResults.AcceptChanges();
                }
            }
            catch (Exception ex)
            {
                string strMsg = "Error Message = " + ex.Message;
            }

You can see in the comments where I want to be able to figure out the new project ID at.  Any help would be appreciated, even if it is to tell me to just subsequently search for the Project based on its title which is what i'm implementing temporarily.

Thanks,
Nathan
0
Comment
Question by:ironwill96
  • 3
  • 3
6 Comments
 
LVL 142

Expert Comment

by:Guy Hengel [angelIII / a3]
Comment Utility
0
 
LVL 2

Author Comment

by:ironwill96
Comment Utility
That ScopeID stuff didn't work for me and is also using SQL-based instead of OleDB-based solutions.  Here is how I am now getting the ProjectID, I just want maybe a faster way, but perhaps this is the best solution possible.

(Add this code right after what I have in my first post):

 try
            {

                //this.mstrSQL = "SELECT ProjectID FROM Projects WHERE (ProjectID = SCOPE_IDENTITY())";  <-- that doesnt work, OleDB doesnt understand the SCOPE_IDENTITY() operator
                this.mstrSQL = "SELECT * FROM Projects WHERE CustomerID = " + cboCustomers.SelectedValue + " AND ProjectTitle = '" + txtProjectTitle.Text + "'";
                this.openDatabase();
                OleDbCommand myCmd = new OleDbCommand(this.mstrSQL, this.dbConnect);
                OleDbDataReader myReader = myCmd.ExecuteReader();
                if (myReader.HasRows)
                {
                    while (myReader.Read())
                    {
                        //we found a value, grab the ProjectID
                        string temp = (string)myReader["ProjectTitle"];
                        this.mintProjectID = (int)myReader["ProjectID"];
                        break;
                    }
                }
                else
                {
                    //we didnt find any values, this is an issue, abort
                    MessageBox.Show("Unable to locate ProjectID from newly created record, aborting.", "Data Value Error");
                    myReader.Close();
                    return;
                }
                myReader.Close();
                this.closeDatabase();
            }
            catch (Exception exp)
            {
                //something went wrong, abort                
                this.closeDatabase();
                MessageBox.Show("Exception thrown during attempt to obtain ProjectID, aborting.", "Fatal Data Error");
                return;
            }

Thanks,
Nathan
0
 
LVL 142

Expert Comment

by:Guy Hengel [angelIII / a3]
Comment Utility
//this.mstrSQL = "SELECT ProjectID FROM Projects WHERE (ProjectID = SCOPE_IDENTITY())";  <-- that doesnt work, OleDB doesnt understand the SCOPE_IDENTITY() operator

Scope_Identity is purely MSSQL Server. in Access, Mysql and SQL Server the @@IDENTITY should work however:
this.mstrSQL = "SELECT ProjectID FROM Projects WHERE (ProjectID =@@IDENTITY)"
0
What Security Threats Are You Missing?

Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

 
LVL 2

Author Comment

by:ironwill96
Comment Utility
Angel,

When I do it that way:

 try
            {

                this.mstrSQL = "SELECT ProjectID FROM Projects WHERE (ProjectID =@@IDENTITY)";
                //this.mstrSQL = "SELECT * FROM Projects WHERE CustomerID = " + cboCustomers.SelectedValue + " AND ProjectTitle = '" + txtProjectTitle.Text + "'";
                this.openDatabase();
                OleDbCommand myCmd = new OleDbCommand(this.mstrSQL, this.dbConnect);
                OleDbDataReader myReader = myCmd.ExecuteReader();
                if (myReader.HasRows)
                {
                    while (myReader.Read())
                    {
                        //we found a value, grab the ProjectID
                        string temp = (string)myReader["ProjectTitle"];
                        this.mintProjectID = (int)myReader["ProjectID"];
                        break;
                    }
                }
                else
                {
                    //we didnt find any values, this is an issue, abort
                    MessageBox.Show("Unable to locate ProjectID from newly created record, aborting.", "Data Value Error");
                    myReader.Close();
                    return;
                }
                myReader.Close();
                this.closeDatabase();
            }
            catch (Exception exp)
            {
                //something went wrong, abort  
                string tempmsg = exp.Message;
                this.closeDatabase();
                MessageBox.Show("Exception thrown during attempt to obtain ProjectID, aborting.", "Fatal Data Error");
                return;
            }

It says "Syntax error (missing operator) in query expression '(ProjectID =@@IDENTITY)'".

Any idea why it doesnt like the syntax of that SQL?

Nathan
0
 
LVL 142

Accepted Solution

by:
Guy Hengel [angelIII / a3] earned 500 total points
Comment Utility
I used @@IDENTITY already with access database, however, I used it differently:
http://support.microsoft.com/default.aspx/kb/232144
so, only "SELECT @@IDENTITY", which returns the value, and then use that value to be put into the actual query.
Possibly that it has to be only that way, not directly part of the insert query itself...
0
 
LVL 2

Author Comment

by:ironwill96
Comment Utility
Thanks, that should work ok for me.

Nathan
0

Featured Post

Enabling OSINT in Activity Based Intelligence

Activity based intelligence (ABI) requires access to all available sources of data. Recorded Future allows analysts to observe structured data on the open, deep, and dark web.

Join & Write a Comment

Bit flags and bit flag manipulation is perhaps one of the most underrated strategies in programming, likely because most programmers developing in high-level languages rely too much on the high-level features, and forget about the low-level ones. Th…
This article describes a simple method to resize a control at runtime.  It includes ready-to-use source code and a complete sample demonstration application.  We'll also talk about C# Extension Methods. Introduction In one of my applications…
Internet Business Fax to Email Made Easy - With eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, fr…
This demo shows you how to set up the containerized NetScaler CPX with NetScaler Management and Analytics System in a non-routable Mesos/Marathon environment for use with Micro-Services applications.

744 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

Need Help in Real-Time?

Connect with top rated Experts

16 Experts available now in Live!

Get 1:1 Help Now