[Solved] Convert string to XXX

What you need is hash and not string. You can use it like this,

hash = {id: 2}
User.where(hash)

And if you really want to use string you can do it like this,

string = "id = 2"
User.where(string)

If you want to execute the string you can use eval. In that case it will be like this,

string = "{id: 2}"
User.where(eval string)