Multiple SQL statements in one roundtrip using Dapper.NET

.net c# dapper sql sql-server

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 command = new SqlCommand("SELECT count(*) FROM TableA; SELECT count(*) FROM TableB;", connection);

using(var reader = command.ExecuteReader())
{
    reader.Read();
    resultA = reader.GetInt32(0);
    reader.NextResult();
    reader.Read();
    resultB = reader.GetInt32(0);
}

Is there a similar feature in Dapper.NET?

Popular Answer

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<int>().Single();
    int countB = multi.Read<int>().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.



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Licensed under: CC-BY-SA with attribution
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Is this KB legal? Yes, learn why