Hi, I get the following error when the same user log in n
borrow more than 1 book at one time.

My LoanRecord tbl in database is like this:
Borrow_Date dateTime 8 (Primary Key)
User_id char 10
Title_id char 10
Title varchar 150
Due_Date dateTime 8
Status char 1


Server Error in '/e-library' Application.
--------------------------------------------------------------------------------

Violation of PRIMARY KEY constraint 'PK_LoanRecord'. Cannot insert duplicate key in object 'LoanRecord'. The statement has been terminated.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: Violation of PRIMARY KEY constraint 'PK_LoanRecord'. Cannot insert duplicate key in object 'LoanRecord'. The statement has been terminated.

Source Error:


Line 224: SqlDataAdapter1.InsertCommand.Parameters("@Status" ).Value = "N"
Line 225: 'SqlConnection1.Open()
Line 226: SqlDataAdapter1.InsertCommand.ExecuteNonQuery()
Line 227: SqlConnection1.Close()
Line 228: End Sub


Source File: c:\inetpub\wwwroot\e-library\Borrow.aspx.vb Line: 226

Stack Trace:


[SqlException: Violation of PRIMARY KEY constraint 'PK_LoanRecord'. Cannot insert duplicate key in object 'LoanRecord'.
The statement has been terminated.]
   System.Data.SqlClient.SqlCommand.ExecuteReader(Com mandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream)
   System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
   e_library.Borrow.Loan(String Title_id, String Title) in c:\inetpub\wwwroot\e-library\Borrow.aspx.vb:226
   e_library.Borrow.DataGrid1_ItemCommand(Object source, DataGridCommandEventArgs e) in c:\inetpub\wwwroot\e-library\Borrow.aspx.vb:147
   System.Web.UI.WebControls.DataGrid.OnItemCommand(D ataGridCommandEventArgs e)
   System.Web.UI.WebControls.DataGrid.OnBubbleEvent(O bject source, EventArgs e)
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)
   System.Web.UI.WebControls.DataGridItem.OnBubbleEve nt(Object source, EventArgs e)
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)
   System.Web.UI.WebControls.LinkButton.OnCommand(Com mandEventArgs e)
   System.Web.UI.WebControls.LinkButton.System.Web.UI .IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEve ntHandler sourceControl, String eventArgument)
   System.Web.UI.Page.RaisePostBackEvent(NameValueCol lection postData)
   System.Web.UI.Page.ProcessRequestMain()




--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:1.1.4322.2032; ASP.NET Version:1.1.4322.2032

[code]

Thanks in advance for any help!

Irene

Read the error:

SqlException: Violation of PRIMARY KEY constraint 'PK_LoanRecord'. Cannot insert duplicate key in object 'LoanRecord'.

It clearly indicates that you are trying to insert a duplicate value in
a primary key column. Check your table structure.

Now the Borrow_Date is primary key. When the user borrow more than
1 book at 1 time, the Borrow_Date will be same for the books he borrowed.

I guess the error is caused by that, am I right?

But the other columns may also have the duplicate values, do i need to create 1 more column such as Number n set it as Primary Key?

Thanks!

Correct. The error is caused due to Borrow_Date.
And yes, you need to create a new column, say, TransactionID,
and set it as Primary Key

Thanks, i'll try it out.