Creating a Queried DataTable From an Existing DataTable

[Lee Ottaway]

I am manually creating a datatable in memory, creating columns etc for
it and then populating it by importing data from files and various
databases. Once I have the datatable in memory (which consists of
around 10000 records) I need to be able to perform queries on it. I'm
not talking about merely filtering or sorting it which I could do with
a DataView, but performing real queries on it like grouping and
counting.

I can obviously do this by saving the datatable to a database and then
using the OleDbDataAdapter to perform these kind of queries, but I
don't want to have to save the data to a database, firstly because I
don't need to store it and secondly because its incredibly slow saving
10000 records across a network.

Is there a way I can perform SQL queries on a datatable that exists
only in memory?

Thanks


Lee

 

[Miha Markic [MVP C#]]

Hi Lee,

I am manually creating a datatable in memory, creating columns etc for
it and then populating it by importing data from files and various
databases. Once I have the datatable in memory (which consists of
around 10000 records) I need to be able to perform queries on it. I'm
not talking about merely filtering or sorting it which I could do with
a DataView, but performing real queries on it like grouping and
counting.

I can obviously do this by saving the datatable to a database and then
using the OleDbDataAdapter to perform these kind of queries, but I
don't want to have to save the data to a database, firstly because I
don't need to store it and secondly because its incredibly slow saving
10000 records across a network.

Is there a way I can perform SQL queries on a datatable that exists
only in memory?

No, there isn't.
You might perform foreach loops (in combination with RowFilter perhaps)
though and check/calculate there.
You might also use DataTable.Select method.