How can I do a batch select in Dapper?

Question

I have a table with a composite primary key of two columns. In Dapper .NET I am using .Query by passing in my select statement, along with an array of the parameters. I found out that dapper only expects a single object for parameters in SELECT statements, unlike Execute for INSERT and UPDATE, where I could do this:

var batchParams = new List<object>();
batchParams.add(new 
    {
    ID = 50,
    Lang = 40
    });
batchParams.add(new 
    {
    ID = 20,
    Lang = 31
    });

And then I could just pass in this array to my execute call. Essentially, I want to run multiple select statements (each will retrieve one row), and then get the result back as an array of results. Is this possible in dapper?

Answer 1

It isn't built in, but you could probably add an extension method that does something like:

foreach(var val in input)
    foreach(var row in conn.Query<T>(sql, val))
        yield return row;

This could also probably be achieved via SelectMany in LINQ-to-Objects:

var  combined = batch.SeletMany(x => conn.Query<T>(sql, x));