Simple SQL query to Couchbase - couchbase

Question

I have the following document:
{
"postId": "Message_2D73B43390041E868694A85A65E47A09D50F019C180E93BAACC454488F67A411_1375457942227",
"userId": "User_2D73B43390041E868694A85A65E47A09D50F019C180E93BAACC454488F67A411",
"post_message": "test",
"attachments": {
"images": [
],
"audio": [
],
"videos": [
]
},
"timestamp": 1375457942227,
"followers": [
],
"follow": 0,
"reporters": [
],
"report": 0,
"rerayz": 0,
"mtype": "post"
}
I would like do the following query:
SELECT * FROM posts WHERE users in ("User_1", "User_2", "User_3") ORDER_BY timestamp LIMIT 20
I did the following and I pass multiple ?keys=["User_1", "User_2", etc] . But how can I get the results sorted by timestamp in order to get only the 20 first?
function (doc, meta) {
if(doc.mtype == "post") {
emit(doc.userId, doc.post_message);
}
}
Any suggestions?
Thanks.

Answer 1

I see two choices here (there are likely more):
Emit the time stamp instead of the user id. loop through the results and filter out the users you want by using code instead of asking couchbase to do it for you. Loop until you have 20 matching records.
You could emit the user id followed by the timestamp. Then search for each user in turn and grab their last 20 posts (each). Put these in some sort of array or structure and sort them (using code) by the timestap. Grab the first 20 entries in your array (which contains 60 items if you have 3 users) and you have what you need.