IDataReader - Any way to get the total rows?

Question

Is there any way to get the total number of rows returned from a SQL query (from the IDataReader) before iterating through the rows by using reader.Read();?

Answer 1

No.

IDataReader is a simple forward-only view of a resultset; it cannot get a count.

Answer 2

No, the datareader will not return a count first. However, if you do need to do it, use two queries that return multiple result sets.

for example in SQL Server:

sql = "SELECT COUNT(1) FROM A; SELECT * FROM A;"

Iterate the result sets. Use the IDataReader on the second result set.

The database server should be able to do this quite fast if it is using appropriate indexes.