Redmine

The advantage of this patch, is that I do not need to alias the sql_for_field method in my plugin!
I am also open for more elegant solution.
Thanks.

For the below cases, With grouping of filters,

Suppose, If I add a custom filter through a plugin patch

     add_available_filter("question.qassigned_to_id", :type => :list, :values => author_values,
         :caption => :field_question_assigned_to_id, :name => l(:field_question_assigned_to_id_esi)
     )

The only way to handle the corresponding SQL query is to alias the sql_for_field.
Instead if the attached patch is provided,
I can avoid the alias and also have my method,

    def sql_for_qassigned_to_id_field(.....)
      .... sql logic...
    end

Thank You.

In your sql_for_fields_with_group-git.diff

      elsif field =~ /^(.+)\./ && respond_to?("sql_for_#{$2}_field")
        # specific statement
        filters_clauses << send("sql_for_#{$2}_field", field, operator, v)

http://ruby-doc.org/core-2.1.1/Regexp.html#class-Regexp-label-Special+global+variables

$1, $2 and so on contain text matching first, second, etc capture group;

But your field =~ /^(.+)\./ has only one parenthesis.