A Query with in Query is called nested Query. >> When we want to retreive data from table using simple query then we are unable to fetch the resultant output then we require nested Query. 1.

A Subquery is a query within another SQL query and embedded within the WHERE clause. A subquery is used to return data that will be used in the main query as a condition to further restrict the data ...

We design a lightweight and unsupervised nested segmentation scheme, and propose how to use the tree arising out of the nested representation of a query to improve retrieval performance. We examine ...