Grails createCriteria mysql IF statement

Question

I'm a newbie in Grails, and I have a big problem. I have this domain:

class Product{

  String name
  Integer priority
  Double quantity
}

I want to sort Products by priority (which IS 0 or 1) - desc, and then sort by quantity. In mysql I do it like this:

select name, IF(quantity>=1,1,0) as q from product
where ...
order by priority desc, q desc, id desc

There is alse CASE statement in mysql, but in Grails I don't have an idea how to create criteria for this.

Thanks in advance!

Answer 1

Product.createCriteria().list(){
    projection{   // 1. because you only want to getname list.
       property("name")
    }
    ge("quantity", 1) // 2. greater than or equal 1

   order("priority", "desc" ) // by default "asc"
   order("quantity", "desc" )
   order("id", "desc" )
};

1. Only Returns the given property in the returned results when you wrapping by "projections".

    projections { property("firstName") }

2. Where a property is greater than or equal to a particular.

    ge("balance", 1000)

3. "desc" or "asc" for descending and ascending respectively. By default, results are sorted in ascending order

Grails Official Doc v4.0.0

Answer 2

One needs to create a custom Order (sql-generating) class to sort on arbitrary expression, or just go with SQL.

Looks like even HQL cannot do that: Product.executeQuery('from Product p order by (id > 100)') fails for me with HQL syntax error.

Answer 3

Try to do something around below :

  select name,IF(quantity>=1,1,0) as q
  from product 
  where ... 
  order by IF(priority=1,0,1), q desc, id desc

Considering Priority 1= high 0=low

Please do required changes