I have 2 datatable, first table for customers personal information and second table for customers areas of interest. this two tables have same ID for same customers.

So, when i want to check my some group of customers(like who intrests on sports stuffs) i need filter my first table according to my second table.

is there any easy way to do it?

thanks for your helps :)

yes you can join then or use nested select statements ,like this





now you have to get all the customers who have interest in football , you can do like this .

select c.custid,c.custname ,i.interestname
from customers c
inner join interest i on i.custid = c.custid
where i.interestname = 'football'

and you can do like this also but this is not i recommend for you.

select c.custid,c.custname ,
            (select i.interestname from interest i where i.custid = c.custid and
             i.interestname = 'football') as InterestName
from customers c

the above query is faster then this.
tip: always try to avoid nested select statements in your query as much as possible. nested select statement slowdown your query.


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