Question

I am trying to learn SQL and currently I’m learning about the COUNT function. I want to test pulling data from multiple tables and i want to return a result set like:

| tablename | row_count |
| Computers | 2000      |
| Buildings | 37        |

So far I haven’t figured out a way to pull the info and make a view like this.

Answer 1

Use a union and a count(*) with a (constant) label:

select 'Computers' as tablename, count(*) as row_count from Computers
union all
select 'Buildings' as tablename, count(*) as row_count from Buildings

Note that using union all (instead of just union) means that rows returned will stay in the order they are selected in the query.