Question

Hey I’m trying to figure out how to convert a statement that works in mySQL into PostgreSQL and curious if anybody knows the solution.

Here is the statement that works in mySQL:

def self.by_name(keywords)
    if keywords
        find(:all, :conditions => ["concat(first_name," ",last_name) like?", "%#{keywords}%"])

    end
  end

Here is the statement that I found on this site that basically had a similar problem, but it doesn’t work for me, as in, if I do a search like Contact.by_name(“Bobby”), there are no results.

def self.by_name(keywords)
    if keywords
        find(:all, :conditions => ["textcat(textcat(first_name,text ' '),last_name) like?", "%#{keywords}%"])
    end
  end

The idea is that I could search for “Bobby”, “Fishcer”, or “Bobby Fischer” and it would match anybody with either that first name, last name, or both first and last name. Thanks!

Answer 1

You can use the concatenation operator (||) to paste everything together:

:conditions => [
  "coalesce(first_name, '') || ' ' || coalesce(last_name, '') ilike '%' || ? || '%'",
  keywords
]

You’ll also notice that I switched from string interpolation, "%#{keywords}%", to string concatenation in the SQL, '%' || ? || '%', to build the search pattern; doing this avoids injection and quoting problems. I’ve also switched to ilike since you probably want a case insensitive search.