How do i set DataRow class to last row of a Sql table

[Plater]

I am so turned around I don't even know where I am anymore.

ArgumentExcepti on is usually thrown when you try to assign a value of one DataType to another DataType incorrectly (like if you Eixttime was a string and you tried to assign it to a DateTime object directly)

As for the other error:

When created, the TargetInvocatio nException is passed a reference to the exception thrown by the method invoked through reflection. The InnerException property holds the underlying exception.

[Frinavale]

The problem you've described is very confusing.
I think you might be trying to solve 2 things and have confused the actual problem.

According to the specifications of the ArgumentExcepti on Class:

"ArgumentExcept ion is thrown when a method is invoked and at least one of the passed arguments does not meet the parameter specification of the called method"

This means that you are passing a function a parameter that is not the right type.
For example: you'll get this exception if you use a method that expects you to pass it a Date object but you pass it a String instead.

According to the specifications of the TargetInvocatio nException Class:

"The exception that is thrown by methods invoked through reflection."

Double check any code that uses Reflection to make sure that it is properly used.

Please re-describe your problem so that we can better understand it.
Post any code snippets that may be the cause of the problem so that we can help you better.

Thanks
-Frinny

[pugalenthi]

[CODE=CPP]
int lastrowidx=this DataSet.Tables["Table"].Rows.Count-1;
DataRow thisRow = thisDataSet.Tab les["Table"].Rows[lastrowidx];
thisRow["Exit_time"] = Exittime;
thisDataSet.Tab les["Table"].Rows.Add(thisR ow);
thisAdapter.Upd ate(thisDataSet , "Table");
[/code]
I feel the problem is in the 4th line. Since im just updating one column data of an already exisiting row (last row), is there another way to do so.

[Plater]

[code=cpp] int lastrowidx=this DataSet.Tables["Table"].Rows.Count-1;
DataRow thisRow = thisDataSet.Tab les["Table"].Rows[lastrowidx];
thisRow["Exit_time"] = Exittime;
thisDataSet.Tab les["Table"].Rows.Add(thisR ow);
thisAdapter.Upd ate(thisDataSet , "Table");[/code]

I feel the problem is in the 4th line. Since im just updating one column data of an already exisiting row (last row), is there another way to do so.

You should be able to just comment out that 4th line. The row is already in your table, why are you trying to add it again?

[pugalenthi]

You should be able to just comment out that 4th line. The row is already in your table, why are you trying to add it again?

Ya i have tried that too, but the column named Exit_time in the last row is not getting modified when i run the code. In the table properties i have set the data type to Datetime and with null value allowed.

[Plater]

Well, I've never used this sort of stuff:
thisAdapter.Upd ate(thisDataSet , "Table");

I've always done it manually, so I don't know much about it.
But I think that you have to like mark the row/colum as "edited" or "dirty" or something like that?

[pugalenthi]

But I think that you have to like mark the row/colum as "edited" or "dirty" or something like that?

I dont understand what you mean.

[Plater]

Try this?
[CODE=CPP]
int lastrowidx=this DataSet.Tables["Table"].Rows.Count-1;
DataRow thisRow = thisDataSet.Tab les["Table"].Rows[lastrowidx];
thisRow["Exit_time"] = Exittime;
thisRow.SetModi fied();
thisAdapter.Upd ate(thisDataSet , "Table");
[/code]

[pugalenthi]

Try this?
[CODE=CPP]
int lastrowidx=this DataSet.Tables["Table"].Rows.Count-1;
DataRow thisRow = thisDataSet.Tab les["Table"].Rows[lastrowidx];
thisRow["Exit_time"] = Exittime;
thisRow.SetModi fied();
thisAdapter.Upd ate(thisDataSet , "Table");
[/code]

I tried it, still im not able to modify the last row value.

[Plater]

I tried it, still im not able to modify the last row value.

And that last row is the only thing not being saved? That's really strange.

[pugalenthi]

How about modifying the table using SQL UPDATE command. Please help me in running the SQL update command in c# to perform the modification.

[Plater]

From what I just read the Update() on a dataadapter only updates values in it's own "data" from the values you supply, it doesn't actually perform any writes back to the database?
Or at least is dependant on the .UpdateCommand like you said.

What does that .UpdateCommand look like?

[pugalenthi]

From what I just read the Update() on a dataadapter only updates values in it's own "data" from the values you supply, it doesn't actually perform any writes back to the database?
Or at least is dependant on the .UpdateCommand like you said.

But I was able to update the table when i used NewRow().

DataRow thisRow = thisDataSet.Tab les["Table"].NewRow();
thisRow["Exit_time"] = Exittime;
thisDataSet.Tab les["Table"].Rows.Add(thisR ow);
thisAdapter.Upd ate(thisDataSet , "Table");

The only difference was i got the Exittime entered everytime in a new row.