grails AJAX call to database

Question

I'm new to grails. I'm trying to develop a simple page with just a dropdown that when the user makes a selection an AJAX call is made to the database. Thing is that there is are no domain files at all in my application. I only have controllers and views and I intend to keep it this way. So I basically want to use grails to issue a mySQL Select statement through AJAX and get the results.

Answer 1

You could do the below:

1. From the AJAX call (I prefer jQuery), make the call to the controller action method.
2. In the controller's method you can use Groovy SQL to execute your query.
3. Return the result as JSON object and display it whatever way you want it to.

Answer 2

See http://groovy.codehaus.org/Tutorial+6+-+Groovy+SQL for a tutorial on executing SQL using the built-in Groovy SQL library. You can then create a controller action and map your resultset to JSON, and you won't even need a GSP view file. Here's an example Controller class that will do basically what you need.

import groovy.sql.Sql

class MyController {

    def sessionFactory

    def myAction() {
        def sql = new Sql(sessionFactory.currentSession.connection())
        sql.execute("select ....") //execute SQL using Groovy SQL

        render(contentType:"application/json") {
            //render your DB query results as JSON
            //you could also use JsonBuilder to render JSON output
        }
    }
}