DataTable to DataTable

[ArunDhaJ]

Hi All,
I'm having a DataTable with say 3 columns. I've to copy this DataTable
to another DataTable which has 4 columns. The extra column is the
Row_ID with AutoIncrement property set true.

Is this way is possible?

Anyways, what I actually need is to add a new column Row_ID with
AutoIncrement values.

Source Table
EName EDesignation
Abc Engineer
Bcd Sr.Engineer

Destination Table should be like this
Row_ID EName EDesignation
1 Abc Engineer
2 Bcd Sr.Engineer

Thats it,

Thanks in Advance
ArunDhaJ

 

[Ignacio Machin ( .NET/ C# MVP )]

Hi All,
I'm having a DataTable with say 3 columns. I've to copy this DataTable
to another DataTable which has 4 columns. The extra column is the
Row_ID with AutoIncrement property set true.

Is this way is possible?

Of course, just do a loop in the first table rows and add a new row to
the second one.

 

[ArunDhaJ]

Is there any way other than looping? As the DataTable would contain
more than 20K records, in that case this would easily infects the
performance.

Thanks
ArunDhaJ

 

[Pavel Minaev]

Is there any way other than looping? As the DataTable would contain
more than 20K records, in that case this would easily infects the
performance.

Since DataTable is an in-memory structure, and is, in fact, just a
glorified List<DataRow> with optional indexing and constraint
checking, there isn't a more efficient way to do what you want (just
as there wouldn't be with plain List<T>).

 

[Ignacio Machin ( .NET/ C# MVP )]

Is there any way other than looping? As the DataTable would contain
more than 20K records, in that case this would easily infects the
performance.

Thanks
ArunDhaJ

Well, anything with 20K rows in memory will have an impact !!!

Besides, think about it, even if YOU do not do the loop, somebody else
would have to do it . There is no way to avoid the loop

I think you better use a DB, cause 40k rows (20k*2 tables) are a lot
to be hold in memory

 

[ArunDhaJ]

Ya. That was the final option which I had. And now proceeding in that
way.
Thanks for your guidance..

Regards
ArunDhaJ

 

[Pavel Minaev]

I think you better use a DB, cause 40k rows (20k*2 tables) are a lot
to be hold in memory

Not really - at 1k per row (which is probably an overestimate), it's
still only 40Mb, which isn't all that much. In fact, if you use SQL
Server with a database of that size, it will likely also load the data
entirely into memory to speed up queries.

Of course, a proper database is still preferrable as soon as you start
to do queries which are more complicated than "WHERE Name = 'John'".