Although tables in SQL databases typically contain massive amounts of data, they’re not always in a format that can be used by data analysts. The data records in these tables need to be filtered ...
Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement. It’s sometimes difficult to know which SQL syntax to use when ...
I've said it before and I'll say it again: If you want to speed up your application, don't look at your code, look at your data access. The two slowest things you can do in application development are ...