How to do pagination using range queries in MongoDB?
Since the collection I was paging had duplicate values I had to create a compound index on ProductName and id.
Create Compound Index
db.ProductGuideItem.ensureIndex({ ProductName:1, _id:1});
This solved my problem.
Reference: https://groups.google.com/d/msg/mongodb-user/3EZZIRJzW_A/oYH79npKZHkJ
Assuming you have these values:
{a:1, b:1}{a:2, b:1}{a:2, b:2}{a:2, b:3}{a:3, b:1}
So you do this for the range based pagination (page size of 2):
1st Page
find().sort({a:1, b:1}).limit(2){a:1, b:1}{a:2, b:1}
2nd Page
find().min({a:2, b:1}).sort({a:1, b:1}).skip(1).limit(2){a:2, b:2}{a:2, b:3}
3rd Page
find().min({a:2, b:3}).sort({a:1, b:1}).skip(1).limit(2){a:3, b:1}
Here are the docs for $min/max:http://www.mongodb.org/display/DOCS/min+and+max+Query+Specifiers
If you don't have duplicate values in your collection, you don't need to use min & max or create a compound index. You can just use $lt & $gt.
You just need to call skip on the cursor
see MongoDB documentation on cursor skip "This approach may be useful in implementing “paged” results".
This example is taken from Mongodb's example
function printStudents(pageNumber, nPerPage) { print("Page: " + pageNumber); db.students.find().skip((pageNumber-1)*nPerPage).limit(nPerPage).forEach( function(student) { print(student.name + "<p>"); } );}