I have a table
Roles(id int,,name vachar(50),role enum(CAD,CA,CM,CV ))
I want select data that order by specific values in specific order . My active model query: role.order('role asc') then the result:
1 name1 CAD
2 name2 CA
3 name2 CM
But I want the result like:
1 name1 CAD
2 name2 CM
3 name2 CA
Can anyone help me? Thanks in advance
A portable solution would be to use a CASE statement as an inlined map in your ORDER BY:
query.order(%q(
case role
when 'CAD' then 1
when 'CM' then 2
when 'CA' then 3
end
))
Keep in mind that you can ORDER BY any expression you want and a CASE certainly is an expression in SQL.
Newer versions of Rails will want you to use Arel.sql rather than a raw string:
query.order(
Arel.sql(
%q(
case role
when 'CAD' then 1
when 'CM' then 2
when 'CA' then 3
end
)
)
)
And if the list is dynamic, you can build a CASE expression:
array = %w[CAD CM CA]
q = connection.method(:quote) # Or ApplicationRecord.connection.method(:quote)
cases = array.each_with_index.map { |e, i| "when #{q[e]} then #{i}" }
query.order(Arel.sql("case role #{cases.join(' ')} end"))
All the string manipulation is a bit ugly but it is perfectly safe and you'd usually hide it in a scope.