Multiple SQL statements in one roundtrip using Dapper.NET

Question

There is a nice feature in ADO.NET that allows you to send multiple SQL statements to database in one roundtrip and receive results for all statements:

var c         


        

Answer 1

Yes, the Dapper QueryMultiple extension can do that:

string query = @"SELECT COUNT(*) FROM TABLEA;
                 SELECT COUNT(*) FROM TABLEB";
using (var multi = connection.QueryMultiple(query, null))
{
    int countA = multi.Read().Single();
    int countB = multi.Read().Single();
}     

According to Marc Gravell this is the ideal way to execute multiple queries in a single batch.

Note: Dapper creator Sam Saffron has posted a detailed explanation with code sample on using QueryMultiple to accomplish this.

UPDATE: I add the important comment from Marc

Note: from 1.5-ish (a little earler on the alpha builds) there is a ReadSingle() method that may be more convenient and efficient than Read().Single()