I’m trying to figure out if there is one way to code the overlap rather then building out 4 distinct queries in T-SQL.

We have a single table called T_DATA, it has columns customer_id, cust_identifier, start_dt, end_dt, and others.

Here is a sample of what our data looks like and we need to return customers 1 and 2.

We are looking to find all the rows that fall into these scenarios.

short of building out nested queries and 4 different joins is there some other simplified ways to build out any kind of overlap.