Squeryl geo queries with a postgres backend? - squeryl

Question

How can I perform geo queries using Squeryl with a postgres backend? The sort of queries I want to run are "return all users within x kilometres", etc.
If geo queries aren't supported directly/through a plugin, how can I run raw SQL queries? I saw one gist and it looked complicated.
Update
Specifically I want to run the following query:
SELECT events.id, events.name FROM events
WHERE earth_box( {current_user_lat}, {current_user_lng},
{radius_in_metres}) #> ll_to_earth(events.lat, events.lng);
This is taken from http://johanndutoit.net/searching-in-a-radius-using-postgres/

Answer 1

This object should solve your problem.
object object RawSql {
def q(query: String, args: Any*) =
new RawTupleQuery(query, args)
class RawTupleQuery(query: String, args: Seq[Any]) {
private def prep = {
val s = Session.currentSession
val st = s.connection.prepareStatement(query)
def unwrap(o: Any) = o match {
case None => null
case Some(ob) => ob.asInstanceOf[AnyRef]
case null => null
case a#AnyRef => a
case a#_ => a
}
for(z <- args.zipWithIndex) {
st.setObject(z._2 + 1, unwrap(z._1))
}
st
}
def toSeq[A1]()(implicit f1 : TypedExpressionFactory[A1,_]) = {
val st = prep
val rs = st.executeQuery
try {
val ab = new ArrayBuffer[A1]
val m1 = f1.thisMapper.asInstanceOf[PrimitiveJdbcMapper[A1]]
while(rs.next)
ab.append(m1.convertFromJdbc(m1.extractNativeJdbcValue(rs, 1)))
ab
}
finally {
rs.close()
st.close()
}
}
def toTupleSeq[A1,A2]()(implicit f1 : TypedExpressionFactory[A1,_], f2 : TypedExpressionFactory[A2,_]) = {
val st = prep
val rs = st.executeQuery
try {
val ab = new ArrayBuffer[(A1,A2)]
val m1 = f1.thisMapper.asInstanceOf[PrimitiveJdbcMapper[A1]]
val m2 = f2.thisMapper.asInstanceOf[PrimitiveJdbcMapper[A2]]
while(rs.next)
ab.append(
(m1.convertFromJdbc(m1.extractNativeJdbcValue(rs, 1)),
m2.convertFromJdbc(m2.extractNativeJdbcValue(rs, 2))))
ab
}
finally {
rs.close()
st.close()
}
}
}
}
I got from this gist:
https://gist.github.com/max-l/9250053