Sql connections

.travis.yml

@@ -4,6 +4,7 @@ python:
  - 3.6
 
 install:
+ - sudo apt-get install unixodbc-dev
  - pip install -r requirements.txt
  - pip install codecov
  - pip install pytest pytest-cov

codonPython/SQL_connections.py

@@ -0,0 +1,33 @@
+''' Author(s): Sam Hollings
+Desc: this module contains SQL_alchemy engines to connect to commonly used databases'''
+
+from sqlalchemy import create_engine
+
+
+def conn_dss():
+    '''Returns sqlalchemy Engine to connect to the DSS 2008 server (DMEDSS) DSS_CORPORATE database '''
+    engine = create_engine('mssql+pyodbc://DMEDSS/DSS_CORPORATE?driver=SQL+Server')
+    return engine
+
+
+def conn_dss2016uat():
+    '''Returns sqlalchemy Engine to connect to the DSS 2016 server (UAT) (DSSUAT) DSS_CORPORATE database '''
+    conn = create_engine('mssql+pyodbc://DSSUAT/DSS_CORPORATE?driver=SQL+Server')
+    return conn
+
+
+def conn_dummy(path=r''):
+    '''connect to the sqlite3 database in memory, or at specified path
+    parameters
+    ----------
+    path : string
+        The location and file in which the database for conn_dummy will be stored. Default is memory (RAM)
+    '''
+
+    conn_string = 'sqlite://'
+    if path != '':
+        path = '/' + path
+
+    conn = create_engine(r'{0}{1}'.format(conn_string, path))
+
+    return conn

codonPython/tests/SQL_connections_test.py

@@ -0,0 +1,15 @@
+'''test script for SQL_connections
+- test the connections can run a dummy script (SELECT 1 as [Code], 'test' as [Name])'''
+import pandas as pd
+import pytest
+import codonPython.SQL_connections as conn
+
+
+@pytest.mark.parametrize("connection",
+                         [conn.conn_dummy(),
+                          conn.conn_dummy('test.db')
+                          ])
+def test_select1(connection):
+    result = pd.read_sql("""SELECT 1 as [Code], 'Test' as [Name]""", connection).iloc[0, 0]
+    expected = pd.DataFrame([{'Code': 1, 'Name': 'Test'}]).iloc[0, 0]
+    assert result == expected

requirements.txt

@@ -1,11 +1,12 @@
 numpy>=1.16.0
 scipy>=0.19.0
 pandas>=0.24.0
-sqlalchemy>=1.3.5
+sqlalchemy>=1.3.12
+pyodbc
 scikit-learn>=0.21.2
 statsmodels>=0.10.0
 seaborn>=0.9.0
 sphinx>=2.2.2
 sphinx-rtd-theme>=0.4.3
 flake8>=3.7.9
-m2r>=0.2.1
+m2r>=0.2.1