Join or clause can't compare to constants

Currently, it doesn’t seem to be possible to generate a query like the following (in MySQL):

select * from `users` inner join `contacts` on `users`.`id` = `contacts`.`id` and `users`.`name` = 'mungo'

My test looks approximately like this. Basically, the on clause doesn’t work with the richness of the where clause, and it probably should. Of course, with integer values JS can tell the difference between strings and identifiers, but not for strings, so it’s escaping a string value as an identifier in all cases.

This is needed because for left and right joins, you can’t move the on clause to the where clause.

    it("complex join with string value", function() {
      testsql(qb().select('*').from('users').join('contacts', function(qb) {
        qb.on('users.id', '=', 'contacts.id').andOn('users.name', 'mungo');
      }), {
        mysql: {
          sql: 'select * from `users` inner join `contacts` on `users`.`id` = `contacts`.`id` or `users`.`name` = \'mungo\'',
          bindings: []
        },
        default: {
          sql: 'select * from "users" inner join "contacts" on "users"."id" = "contacts"."id" or "users"."name" = \'mungo\'',
          bindings: []
        }
      });
    });

I’ll probably work on a patch/pull request later.

[bendrucker]

Important change I realized was needed while testing. knex.raw(true) is fine, but you can’t do the same for a string since it won’t be escaped. So the documented recommendation is to use a binding:

this.on('pledges.id', 'payments.pledge_id')
      .on('payments.paid', knex.raw('?', [true]));

I know this looks gross but I can’t think of a better way to address it.

[OlivierCavadenti]

As I can read, we always need to make something, maybe I can reopen it if anyone want to make a PR ?