Database
[{"blogId":1,"blogTitle":"Book","blogContent":"demo","blogrelatedLink":{"relatedBloogId":"123","relatedBlogTitle":"abc"}}]
Query
db.collection.update({blogId:1},{$set:{blogTitle:"Updated Book Title",blogContent:"Updated demo content","blogrelatedLink.relatedBloogId":"book id updated","blogrelatedLink.relatedBlogTitle":"updated blog title"}})