MVC with no Entity Framework - mysql

Question

From the below source tutorials:
https://www.youtube.com/watch?v=Jt9vSY802mM
http://www.dotnetawesome.com/2017/07/curd-operation-on-fullcalendar-in-aspnet-mvc.html
How do I do the above code samples without Entity Framework, by just using SQL queries?
For example in the above source code, instead of
var v = dc.Events.Where(a => a.EventID == eventID).FirstOrDefault();
if (v != null)
{
dc.Events.Remove(v);
dc.SaveChanges();
status = true;
}
I want to do
DELETE FROM Even WHERE EventID = {0}

Answer 1

FirstOrDefault() in LINQ is equivalent to LIMIT 1 in MySQL, hence the LINQ function can be converted to SQL commands using IF or CASE WHEN like this (assumed commands are running inside a stored procedure):
DELIMITER //
-- 'Events' is a DbSet name by common convention,
-- therefore table name should be 'Event'
CREATE PROCEDURE procedure_name (IN eventID INT)
BEGIN
DECLARE v INT;
SET v = SELECT EventID FROM Event WHERE EventID = eventID LIMIT 1;
CASE WHEN v IS NOT NULL
THEN DELETE FROM Event WHERE EventID = v
ELSE -- do something else
END
-- alternative:
-- IF(v IS NOT NULL, DELETE FROM Event WHERE eventID = v, 0)
-- other stuff here
END//
DELIMITER ;
Note: If EventID is a primary key column, you can remove LIMIT 1 because query result only return single value.
Then, use CALL procedure_name(eventID) or include procedure_name in MySqlCommand to execute it.

Answer 2

Couple of ways:
using raw query in Entity Framework:
Open connection string via SqlConnection and execute:
Pseudo code for method 1:
string sqlDeleteStatement = "DELETE FROM Even WHERE EventID = #id";
List<SqlParameter> parameterList = new List<SqlParameter>();
parameterList.Add(new SqlParameter("#id", 1)); delete id = 1
_context.Database.SqlQuery(sqlDeleteStatement, parameterList);
Pseudo code for method 2:
using(SqlConnection conn = new SqlConnection())
{
conn.ConnectionString = "Server=[server_name];Database=[database_name];Trusted_Connection=true";
string sqlDeleteStatement = "DELETE FROM Even WHERE EventID = #id";
SqlCommand command = new SqlCommand(sqlDeleteStatement , conn);
command.Parameters.Add(new SqlParameter("#id", 1)); //delete id = 1
command.ExecuteNonQuery();
}