ENH: Support index=True for io.sql.get_schema

Closes pandas-dev#9084

- Decided to keep the default as index=False to keep the API consistent. `to_sql` has index=True.
- Tempted to name the parameter `include_dataframe_index` as "index" has
a different meaning in a SQL context.

Author: Vraj Mohan

pandas/io/sql.py

@@ -1222,8 +1222,9 @@ def drop_table(self, table_name, schema=None):
             self.get_table(table_name, schema).drop()
             self.meta.clear()
 
-    def _create_sql_schema(self, frame, table_name, keys=None, dtype=None):
-        table = SQLTable(table_name, self, frame=frame, index=False, keys=keys,
+    def _create_sql_schema(self, frame, table_name, keys=None, dtype=None,
+                           index=False):
+        table = SQLTable(table_name, self, frame=frame, index=index, keys=keys,
                          dtype=dtype)
         return str(table.sql_schema())
 
@@ -1564,13 +1565,14 @@ def drop_table(self, name, schema=None):
             name=_get_valid_sqlite_name(name))
         self.execute(drop_sql)
 
-    def _create_sql_schema(self, frame, table_name, keys=None, dtype=None):
-        table = SQLiteTable(table_name, self, frame=frame, index=False,
+    def _create_sql_schema(self, frame, table_name, keys=None, dtype=None,
+                           index=False):
+        table = SQLiteTable(table_name, self, frame=frame, index=index,
                             keys=keys, dtype=dtype)
         return str(table.sql_schema())
 
 
-def get_schema(frame, name, keys=None, con=None, dtype=None):
+def get_schema(frame, name, keys=None, con=None, dtype=None, index=False):
     """
     Get the SQL db table schema for the given frame.
 
@@ -1592,4 +1594,5 @@ def get_schema(frame, name, keys=None, con=None, dtype=None):
     """
 
     pandas_sql = pandasSQL_builder(con=con)
-    return pandas_sql._create_sql_schema(frame, name, keys=keys, dtype=dtype)
+    return pandas_sql._create_sql_schema(
+        frame, name, keys=keys, dtype=dtype, index=index)

pandas/tests/io/test_sql.py

@@ -823,6 +823,19 @@ def test_get_schema_keys(self):
         constraint_sentence = 'CONSTRAINT test_pk PRIMARY KEY ("A", "B")'
         assert constraint_sentence in create_sql
 
+    def test_get_schema_with_index(self):
+        frame = DataFrame({
+            'one': pd.Series([1, 2, 3], index=['a', 'b', 'c']),
+            'two': pd.Series([1, 2, 3], index=['a', 'b', 'c'])
+        })
+        frame.index.name = 'alphabet'
+
+        create_sql = sql.get_schema(frame, 'test', con=self.conn)
+        assert 'alphabet' not in create_sql
+
+        create_sql = sql.get_schema(frame, 'test', con=self.conn, index=True)
+        assert 'alphabet' in create_sql
+
     def test_chunksize_read(self):
         df = DataFrame(np.random.randn(22, 5), columns=list('abcde'))
         df.to_sql('test_chunksize', self.conn, index=False)