... it turns out that merely extracting the SQL parts was not good enough for some of our audience. They asked, “Can we download just the SQL connection classes, without the query objects or the mapper?” As with Solar, we had to answer, “No; although the Aura.Sql package is independent from every other Aura package, the various SQL tools all have be taken together as a whole.”
As a result, we have done even more decoupling with the Aura.Sql-v2 packages. We have managed to make these packages independent from each other:
Aura.Sql-v2 is composed primarily of an extended PDO implementation, along with a connection manager and a bare-bones profiler. Its only dependency is the native PDO; there are no userland dependencies. As an added bonus, we have taken pains to make it PHP 5.3 compatible.
Aura.Sql_Query is a package of SELECT, INSERT, UPDATE, and DELETE query objects for MySQL, PostgreSQL, SQLite, and Microsoft SQL Server. It has no dependencies at all, not even on PDO. You build your query with the object, then pass it along to the database abstraction layer of your choice. Because it uses traits, it is for PHP 5.4 and up.
Aura.Sql_Schema comprises “list tables” and “list columns” functionality for MySQL, PostgreSQL, SQLite, and Microsoft. As with Aura.Sql-v2, its only dependency is the native PDO (note, not the Aura.Sql-v2 ExtendedPdo). Also as with Aura.Sql-v2, it is PHP 5.3 compatible.
With this dedicated effort at decoupling and true indpedendence, you can now use just the extended PDO connection object, or the query objects, or the schema discovery tools, without having to download the others. Of course, you can use them all in concert if you like.
via Aura for PHP.