Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement.

SQL SELECT statement The SELECT statement tells the query optimizer what data to return, what tables to look in, what relations to follow, and what order to impose on the returned data.

SQL Basics I: Data Queries —covers database terminology and the four basic query types. SQL Basics: SELECT statement options —covers the SELECT statement in detail and explains aggregate ...

SQL is used to interact with databases. Learning the language can take your Android development game to a whole new level. This primer will get you started.