Question

Can Dapper batch a set of stored proc calls? I see it supports Multiple Results in the documentation but I’m not sure if you can execute multiple stored proc calls using Dapper.

Answer 1

Dapper supports batching commands for stored procs:

connection.Execute("create table #t (i int)");
connection.Execute("create proc #spInsert @i int as insert #t values (@i)");
connection.Execute("#spInsert", new[] { new { i = 1 }, new {i = 2}, new {i = 3} }, 
    commandType: CommandType.StoredProcedure);

var nums = connection.Query<int>("select * from #t order by i").ToList();

nums[0].IsEqualTo(1);
nums[1].IsEqualTo(2);
nums[2].IsEqualTo(3);

The code above reuses the IDbCommand with the text #spInsert, 3 times. This makes batching inserts a bit more efficient.

In general if you worry about perf at this level you would wrap the batch call in a transaction.

Additionally Dapper supports whatever batch you decide to send it:

connection.Execute(@"
    exec #spInsert @i = @one 
    exec #spInsert @i = @two 
    exec #spInsert @i = @three",
    new { one = 1, two = 2, three = 3 });

Which would cause three rows to be inserted.

Further more, if #spInsert returned a result set you could use QueryMultiple to execute the batch which would give you 3 record sets to iterate through.