Chris Jones has a new post to his site showing you how to use Oracle 12c's implicit result sets in your code. Note: this functionality is still in development, so the naming/exact functionality might change.
The new Oracle Database 12c "Implicit Result Sets" (IRS) feature allows query results to be returned from a stored PL/SQL procedure (or a PL/SQL anonymous block) without requiring special PHP code. Support for IRS is available in PHP OCI8 2.0.0-devel extension when it is compiled and used with Oracle Database 12c. (OCI8 2.0 can be compiled and used with other versions of Oracle Database but the available feature set is reduced).
He shows a normal fetch loop that calls the oci_* functions and grabs each row with a oci_fetch_row call. He updates this to use an anonymous PL/SQL block (a string) instead that allows for more flexibility. He includes examples that fetch from one table, multiple tables and returns multiple result sets (that can be fetched one at a time) from the same single call.