Limit response time of my SQL query

I have posted a question here regarding bindi开发者_Go百科ng of my gridview - Bind GridView with many records with number of visible records at a moment. The performance hit has come down incredibily to 2sec from 20sec by implementing the answer but still i know it can be lowered to more limit.

Like- When i fetch say 50 records(Customers) at a time from DB, it has one column which fetch number of orders corresponding to that customer from Orders table(just count not complete record). So, it hit 50 queries to a SQL Server to fetch data for 50 customers. Is there a way where i can fetch complete data with a single query??

NOTE- If someone needs to look at a code, do let me know. Hopefuly, the link which i have provided contains enough codebase..

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Database Indexing was what i was looking for.