mapping scalar value function using fluent map api

[Ezequiel]

I have a function in Mysql, that function returns a DateTime, i need map that function using fluent map api.. there is a way?
regards.

[Kaloyan Nikolov]

Hello Ezequiel,

 
With OpenAccess ORM you are able to work with database functions in both ways:

In LINQ statements (documentation)
Example: 

var projects = from p in dbContext.Projects
          select new
          {
              ProjectId = p.Id,
              Name = p.Name,
              LastActivity = FluentModel.GetLastActivity(p.Id)
          };

 
To achieve that you should define a static method in your FluentContext equivalent of the database function you want to call. This method will not be called explicitly, it is only a marker for OpenAccess to translate the method call to a function call at runtime.

Example:

[MappedFunctionAttribute(Name = "`GetLastActivity`", IsDeterministic = false, Backend = Backend.MySql)]
public static System.DateTime GetLastActivity(int? Id)
{
    throw new NotImplementedException();
}

Invoking from the context
Example:

var date = dbContext.GetLastActivity(12);

If you want to execute it that way you should use the OpenAccess ADO API to implement a non-static method in your fluent context class, like the example below:

public DateTime GetLastActivity(int? Id)
{
    OAParameter parameteId = new OAParameter();
    parameteId.ParameterName = "@Id";
    if (Id.HasValue)
    {
        parameteId.Value = Id.Value;
    }
    else
    {
        parameteId.DbType = DbType.Int32;
        parameteId.Value = DBNull.Value;
    }

    DateTime date = this.ExecuteScalar<DateTime>("SELECT `GetLastActivity`(@Id)", parameteId);

    return date;
}

I hope that helps. Do not hesitate to contact us if you have other questions.

Regards,
Kaloyan Nikolov
the Telerik team