.. -*- coding: utf-8; -*-

======
 SQL.
======
.. contents::
   :local:

Joins.
======

http://www.codinghorror.com/blog/2007/10/a-visual-explanation-of-sql-joins.html
  A Visual Explanation of SQL Joins.

Primary key length.
===================

For ``int`` type (32-bit): ``NUMBER(9)``. For ``long`` type (64-bit):
``NUMBER(18)``.

Oracle allow up to 38 significant digits in ``NUMBER`` and up to 28 digits in
``SEQUENCE``.

http://docs.oracle.com/cd/B28359_01/server.111/b28318/datatype.htm
  Oracle Data Types
http://docs.oracle.com/cd/B28359_01/server.111/b28286/statements_6015.htm
  CREATE SEQUENCE.
http://docs.oracle.com/cd/E19501-01/819-3659/gcmaz/index.html
  Java Type to SQL Type Mappings.