CODEWITHSUNDEEP
c#.netsql
RPS
RPS

Reputation: 837

SqlDataReader return rows

If we select a large number of rows and use an SqlDataReader, will it return the rows as they come or will it wait until the operation is complete?

This is with C#.net

Upvotes: 0

Views: 1348

Answers (2)

djdd87
djdd87

Reputation: 68456

It'll return the rows as they come. Each time you call SqlDataReader.Read(); the next row is retrieved from the client's network buffer. Only one row is held in memory on each Read().

// Starts getting the data from the query 
IDataReader reader = cmd.ExecuteReader(behavior); 

// Calling .Read() will get the next result from the client network buffer
while (reader.Read())
{
   // Do something with the row data
}

More information here.

Upvotes: 1

Adam Houldsworth
Adam Houldsworth

Reputation: 64467

They are streamed. If you review the "remarks" section it states that certain properties can only be safely read once the reader closes. If the complete result set was known prior to starting, these properties would be safe to read while the reader was open.

http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqldatareader.aspx

Upvotes: 0

Related Questions