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 ...

A join combines two or more tables side by side. If you do not specify how to join the tables, you get a Cartesian product. This means that SQL combines each row from the first table with every row ...

The INNER JOINS: Matching records only In December 2001’s “Another crash course in SQL,” I showed you one way to extract information from two tables in one statement. In most implementations ...

You get the Cartesian product when you join two tables and do not subset them with a WHERE clause or ON clause. proc sql; title 'The Cartesian Product of'; title2 'LEFTTAB and RIGHTTAB'; select * from ...