Is it possible to have variable search conditions for key and value?

Question

I am trying to pass both a field and a value in a find call:

@employee = Employee.find(:all,
              :conditions => [ '? = ?', params[:key], params[:value].to_i)

Output signal

SELECT * FROM `employees` WHERE ('is_manager' = 1)

This does not return any results, however, when I try to execute it directly in mysqsl using the same call without `` around is_manager, it works fine. How to convert the value of params [: key] to a character so that the resulting SQL query looks like this:

SELECT * FROM `employees` WHERE (is_manager = 1)

Thanks D

Answer 1

You can use variable substitution for the column name instead of using binding values:

# make sure the key passed is a valid column
if Employee.columns_hash[params[:key]]
  Employee.all :conditions => [ "#{params[:key]} = ?", params[:value]]
end

You can also protect the solution by indicating that the passed column name belongs to a preselected collection:

if ["first_name", "last_name"].include? [params[:key]]
  Employee.all :conditions => [ "#{params[:key]} = ?", params[:value]]
end

Answer 2

( , params [: key], , ,

params[:key].to_s.to_sym

2 :

• : .

• , , to_s to_sym, , wierd , :

  :"5"

Answer 3

"string" .to_sym