I am using Scala Play 2.x with MongoDB in backend and I must confess that Salat has wonderful support for mongo CRUD operations.
But so far I didn't find any good example of how I can call mongo aggregate function using SALAT like $unwind, $match, $group or aggregate pipeline.
For example
db.posts.aggregate([
{
$unwind :"$tag"
},
{ $group :
{
_id :"$tags",
count : {$sum :1}
}
},
{
$sort : {$post :-1}
},
{
$limit :1
}
])
UPDATE (ALTERNATIVE) I didn't find any help which systematically explain usage of
aggregate query in SALAT. So as an work around I also added casbah which has a
support for AGGREGATE QUERIES in SBT and able to open work in parallel with SALAT.
val appDependencies = Seq(
"se.radley" %% "play-plugins-salat" % "1.3.0",
"org.mongodb" %% "casbah" % "2.6.3"
)
Thanks in advance
My salat version:
libraryDependencies ++= Seq(
"se.radley" %% "play-plugins-salat" % "1.4.0"
)
The code example:
dao.collection.aggregate(
MongoDBObject(
"$unwind" -> "$tag"
),
MongoDBObject(
"$group" -> MongoDBObject(
"_id" -> "$tags",
"count" -> MongoDBObject("$sum" -> 1)
)
),
MongoDBObject(
"$sort" -> MongoDBObject(
"$post" -> -1
)
),
MongoDBObject(
"$limit" -> 1
)
)