Fixes kayak#299 Add database object and added attribute references fo…

…r database->schema and schema->table

README.rst

@@ -32,7 +32,7 @@ Installation
 
 .. _installation_start:
 
-|Brand| supports python ``3.3+``.  It may also work on pypy, cython, and jython, but is not being tested for these versions.
+|Brand| supports python ``3.4+``.  It may also work on pypy, cython, and jython, but is not being tested for these versions.
 
 To install |Brand| run the following command:
 
@@ -79,10 +79,18 @@ Alternatively, you can use the `Query.get_sql()` function:
 
     q.get_sql()
 
-Using ``pypika.Table``
+
+Tables, Columns, Schemas, and Databases
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+In simple queries like the above example, columns in the "from" table can be referenced by passing string names into
+the ``select`` query builder function. In more complex examples, the ``pypika.Table`` class should be used. Columns can be
+referenced as attributes on instances of ``pypika.Table``.
 
 .. code-block:: python
 
+    from pypika import Table, Query
+
     customers = Table('customers')
     q = Query.from_(customers).select(customers.id, customers.fname, customers.lname, customers.phone)
 
@@ -92,18 +100,42 @@ Both of the above examples result in the following SQL:
 
     SELECT id,fname,lname,phone FROM customers
 
-Using ``pypika.Table`` based select alias
+An alias for the table can be given using the ``.as_`` function on ``pypika.Table``
 
-.. code-block:: python
+.. code-block:: sql
 
-    customers = Table('customers')
-    q = customers.select(customers.id, customers.fname)
+    Table('x_view_customers').as_('customers')
+    q = Query.from_(customers).select(customers.id, customers.phone)
+
+.. code-block:: sql
+
+    SELECT id,phone FROM x_view_customers customers
+
+A schema can also be specified. Tables can be referenced as attributes on the schema.
+
+.. code-block:: sql
+
+    from pypika import Table, Query, Schema
+
+    views = Schema('views')
+    q = Query.from_(views.customers).select(customers.id, customers.phone)
+
+.. code-block:: sql
+
+    SELECT id,phone FROM views.customers
+
+Also references to databases can be used. Schemas can be referenced as attributes on the database.
+
+.. code-block:: sql
+
+    from pypika import Table, Query, Database
 
-query will return in the following SQL:
+    my_db = Database('my_db')
+    q = Query.from_(my_db.analytics.customers).select(customers.id, customers.phone)
 
 .. code-block:: sql
 
-    SELECT id, fname FROM customers
+    SELECT id,phone FROM my_db.analytics.customers
 
 
 Results can be ordered by using the following syntax:

pypika/__init__.py

@@ -54,6 +54,7 @@
     Query,
     Schema,
     Table,
+    Database,
     make_tables as Tables,
 )
 # noinspection PyUnresolvedReferences

pypika/queries.py

@@ -35,6 +35,10 @@ class Selectable:
     def __init__(self, alias):
         self.alias = alias
 
+    @builder
+    def as_(self, alias):
+        self.alias = alias
+
     def field(self, name):
         return Field(name, table=self)
 
@@ -79,6 +83,9 @@ def __eq__(self, other):
     def __ne__(self, other):
         return not self.__eq__(other)
 
+    def __getattr__(self, item):
+        return Table(item, schema=self)
+
     def get_sql(self, quote_char=None, **kwargs):
         # FIXME escape
         schema_sql = format_quotes(self._name, quote_char)
@@ -91,6 +98,11 @@ def get_sql(self, quote_char=None, **kwargs):
         return schema_sql
 
 
+class Database(Schema):
+    def __getattr__(self, item):
+        return Schema(item, parent=self)
+
+
 class Table(Selectable):
     @staticmethod
     def _init_schema(schema):

pypika/tests/test_tables.py

@@ -1,15 +1,48 @@
 import unittest
 
 from pypika import (
+    Database,
     Schema,
     Table,
-    Tables
+    Tables,
 )
 
 __author__ = "Timothy Heys"
 __email__ = "theys@kayak.com"
 
 
+class TableStructureTests(unittest.TestCase):
+    def test_table_sql(self):
+        table = Table('test_table')
+
+        self.assertEqual('"test_table"', str(table))
+
+    def test_table_with_alias(self):
+        table = Table('test_table').as_('my_table')
+
+        self.assertEqual('"test_table" "my_table"', table.get_sql(with_alias=True, quote_char='"'))
+
+    def test_schema_table_attr(self):
+        table = Schema('x_schema').test_table
+
+        self.assertEqual('"x_schema"."test_table"', str(table))
+
+    def test_table_with_schema_arg(self):
+        table = Table("test_table", schema=Schema('x_schema'))
+
+        self.assertEqual('"x_schema"."test_table"', str(table))
+
+    def test_database_schema_table_attr(self):
+        table = Database('x_db').x_schema.test_table
+
+        self.assertEqual('"x_db"."x_schema"."test_table"', str(table))
+
+    def test_table_with_schema_and_schema_parent_arg(self):
+        table = Table("test_table", schema=Schema('x_schema', parent=Database('x_db')))
+
+        self.assertEqual('"x_db"."x_schema"."test_table"', str(table))
+
+
 class TableEqualityTests(unittest.TestCase):
     def test_tables_equal_by_name(self):
         t1 = Table("t")