I have a strange situation. I have an existing stored procedure that returns a data back, everything works fine until sql exception occured. When SQL exception occured and this even handled by begin catch, but Dapper for some reason throws an exception Sequence contains no elements. Then I replaced QuerySingleAsync<T> to QueryAsync to be able to see the sql result itself. It helped to mute the exception (that was generated by Dapper mapper), but result came back empty. I can’t understand why Dapper doing this way.

SQL

ALTER PROCEDURE [dbo].[MyFavSP]
    @SomeName VARCHAR(60),
    @SomeValue BIGINT
AS
BEGIN
    DECLARE @errMessage VARCHAR(256)
    DECLARE @sqlErrCode INT = 0;    

    BEGIN TRY
        select * from MyTable 
        WHERE 1/0 = 25

        set @sqlErrCode = 111
        set @errMessage = 'good'
    END TRY
    BEGIN CATCH

        set @sqlErrCode = 999
        set @errMessage = 'bad'
        
    END CATCH

    SELECT @sqlErrCode ErrorCode, @errMessage ErrorMessage
END

C#

var result = await connection.QuerySingleAsync<MyResult>("dbo.MyFavSP",
    new {SomeName = "MyName", SomeValue = 123},
    commandType: CommandType.StoredProcedure);