Creating a subselect

- [Narrator] A subselect is, effectively, nested queries.…In SQL, the result of a select statement…is, effectively, a table and can always be used…as you would use a table.…Because of this, a select statement…may be used as a data source in another select statement.…This usage is called a subselect.…We'll select the world database for this example…and I'm gonna come out here to our…exercise files for chapter 11…and I'm just going to grab those statements there…from the create table to the select from T…and I'll paste that in here and run it.…

And, you see we've created a table with two columns…and we're inserting in these values.…And when we look at these values,…we'll notice the first two characters is a two-letter code.…In column A, that two-letter code is a state code…and in column B, that two letter code is a country code,…a standardized country code.…And, then there's these other numbers,…which we're calling it a code for our purposes,…because this is an interesting way to pack data…and you'll find packed data like this a lot of databases.…