How to use Dapper asynchronously with multiple stored procedure calls? - asp.net

Question

I'm using the Dapper ORM in an ASP.Net Core 2.1 CRUD application, with a SQL Server database. For a new form I'm developing, I want to retrieve all reference data (to populate SELECT field options) in one go when the screen is invoked. This involves a series of stored procedure calls, which I want to do asynchronously for best performance.
This Dapper tutorial suggests I should look at using QueryMultipleAsync, but I can't find an example of its use with stored procedures, only hard-coded SQL statements.
My C# code currently looks like this:
public async Task<ContactReferenceData> Get()
{
ContactReferenceData refData = new ContactReferenceData();
try
{
using (IDbConnection dbConnection = _connection)
{
dbConnection.Open();
var countryData = await dbConnection.QueryAsync<Country>(sql: "usp_GetCountries", commandType: CommandType.StoredProcedure);
refData.CountryDetails = countryData.AsList();
var companyData = await dbConnection.QueryAsync<Company>(sql: "usp_GetCompanies", commandType: CommandType.StoredProcedure);
refData.CompanyDetails = companyData.AsList();
var groupData = await dbConnection.QueryAsync<Group>(sql: "usp_GetGroups", commandType: CommandType.StoredProcedure);
refData.GroupDetails = groupData.AsList();
var groupPositionData = await dbConnection.QueryAsync<GroupPosition>(sql: "usp_GetGroupPositions", commandType: CommandType.StoredProcedure);
refData.GroupPositionDetails = groupPositionData.AsList();
}
return refData;
}
catch (Exception ex)
{
_logger.LogError(ex.ToString());
throw;
}
}
This works OK in my test environment, but I'm not sure it's the correct way to execute async queries. In particular, I have the following concerns:
is it robust enough to be trusted in live operation?
in its current form, is it maximising the benefits (if any) of asynchronous operation, or should I be using QueryMultipleAsync to properly achieve this?

Answer 1

Have you tried something like this?
public async Task<ContactReferenceData> Get()
{
var sql = "EXEC usp_GetCountries; EXEC usp_GetCompanies; EXEC usp_GetGroups; EXEC usp_GetGroupPositions";
ContactReferenceData refData = new ContactReferenceData();
try
{
using (IDbConnection dbConnection = _connection)
{
using (var multi = connection.QueryMultipleAsync(sql: sql, commandType: CommandType.StoredProcedure ).Result)
{
refData.CountryDetails = multi.Read<countryDetails>().ToList();
refData.CompanyDetails = multi.Read<CompanyDetails>().ToList();
refData.GroupData = multi.Read<Groups>().ToList();
refData.GroupPositionsData= multi.Read<GroupPositions>().ToList();
}
}
return refData;
}
catch (Exception ex)
{
_logger.LogError(ex.ToString());
throw;
}
}