single DataSet having multiple DataTables from multiple databases

[Hailu Worku Obsse]

It is possible to have a single DataSet having multiple DataTables from multiple databases. If so can you just tell me how ?

[Richard Deeming]

Yes it is.

var ds = new DataSet();

using (var connection = new SqlConnection("..."))
{
var da = new SqlDataAdapter("SELECT ...", connection);
da.SelectCommand.Parameters.AddWithValue(...);
da.Fill(ds, "FirstTable");
}

using (var connection = new OleDbConnection("..."))
{
var da = new OleDbDataAdapter("SELECT ...", connection);
da.SelectCommand.Parameters.AddWithValue(...);
da.Fill(ds, "SecondTable");
}

If one of your queries returns multiple result-sets, you might need to use TableMappings to specify the table names: DataAdapter DataTable and DataColumn Mappings | Microsoft Docs[^]

---

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

[Mycroft Holmes]

Many years ago I experimented with SQL Server returning multiple tables from a single stored procedure. The performance was dramatically slower then return multiple single tables from individual stored procs. Performance may have changed in recent versions.

Never underestimate the power of human stupidity RAH

[Hailu Worku Obsse]

Thank you for your replay .... however, I am looking different databases from the same provider

[Richard Deeming]

So load data from different databases from the same provider then. What's the problem?

---

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

[Lost User]

MARS be slow, but selecting from a different DB is hardly noticable on SQL Server. Also doesn't need much mucking with datasets, just plain SQL.

Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^][](X-Clacks-Overhead: GNU Terry Pratchett)