Use Dash to Build to Web Apps on SAP Business Warehouse Data

The rich ecosystem of Python modules lets you get to work quickly and integrate your systems more effectively. With the CData Python Connector for SAP Business Warehouse, the pandas module, and the Dash framework, you can build SAP Business Warehouse-connected web applications for SAP Business Warehouse data. This article shows how to connect to SAP Business Warehouse with the CData Connector and use pandas and Dash to build a simple web app for visualizing SAP Business Warehouse data.

With built-in, optimized data processing, the CData Python Connector offers unmatched performance for interacting with live SAP Business Warehouse data in Python. When you issue complex SQL queries from SAP Business Warehouse, the driver pushes supported SQL operations, like filters and aggregations, directly to SAP Business Warehouse and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations).

Connecting to SAP Business Warehouse Data

Connecting to SAP Business Warehouse data looks just like connecting to any relational data source. Create a connection string using the required connection properties. For this article, you will pass the connection string as a parameter to the create_engine function.

To connect to SAP Business Warehouse, set the URL property to a valid SAP Business Warehouse server base URL. The driver must connect to SAP Business Warehouse instances hosted over HTTP with XMLA access.

The driver supports the following authentication schemes via the AuthScheme property:

• None: Anonymous authentication, if available on the server.
• Basic: Set User and Password and set AuthScheme to Basic.
• Kerberos: See the Using Kerberos section of the help documentation for the required Kerberos properties.

By default, the driver attempts to negotiate SSL/TLS by checking the server's certificate against the system's trusted certificate store. To specify another certificate, see the SSLServerCert property for the available formats.

After installing the CData SAP Business Warehouse Connector, follow the procedure below to install the other required modules and start accessing SAP Business Warehouse through Python objects.

Install Required Modules

Use the pip utility to install the required modules and frameworks:

pip install pandas
pip install dash
pip install dash-daq

Visualize SAP Business Warehouse Data in Python

Once the required modules and frameworks are installed, we are ready to build our web app. Code snippets follow, but the full source code is available at the end of the article.

First, be sure to import the modules (including the CData Connector) with the following:

import os
import dash
import dash_core_components as dcc
import dash_html_components as html
import pandas as pd
import cdata.sapbusinesswarehouse as mod
import plotly.graph_objs as go

You can now connect with a connection string. Use the connect function for the CData SAP Business Warehouse Connector to create a connection for working with SAP Business Warehouse data.

cnxn = mod.connect("URL=https://mysapserver:8000;AuthScheme=Basic;User=username;Password=password;")

Execute SQL to SAP Business Warehouse

Use the read_sql function from pandas to execute any SQL statement and store the result set in a DataFrame.

df = pd.read_sql("SELECT CustomerCount, City FROM Sales WHERE Country = 'US'", cnxn)

Configure the Web App

With the query results stored in a DataFrame, we can begin configuring the web app, assigning a name, stylesheet, and title.

app_name = 'dash-sapbusinesswarehouseedataplot'

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
app.title = 'CData + Dash'

Configure the Layout

The next step is to create a bar graph based on our SAP Business Warehouse data and configure the app layout.

trace = go.Bar(x=df.CustomerCount, y=df.City, name='CustomerCount')

app.layout = html.Div(children=[html.H1("CData Extension + Dash", style={'textAlign': 'center'}),
	dcc.Graph(
		id='example-graph',
		figure={
			'data': [trace],
			'layout':
			go.Layout(title='SAP Business Warehouse Sales Data', barmode='stack')
		})
], className="container")

Set the App to Run

With the connection, app, and layout configured, we are ready to run the app. The last lines of Python code follow.

if __name__ == '__main__':
    app.run_server(debug=True)

Now, use Python to run the web app and a browser to view the SAP Business Warehouse data.

python sapbusinesswarehouse-dash.py

Free Trial & More Information

Download a free, 30-day trial of the CData Python Connector for SAP Business Warehouse to start building Python apps with connectivity to SAP Business Warehouse data. Reach out to our Support Team if you have any questions.

Full Source Code

import os
import dash
import dash_core_components as dcc
import dash_html_components as html
import pandas as pd
import cdata.sapbusinesswarehouse as mod
import plotly.graph_objs as go

cnxn = mod.connect("URL=https://mysapserver:8000;AuthScheme=Basic;User=username;Password=password;")

df = pd.read_sql("SELECT CustomerCount, City FROM Sales WHERE Country = 'US'", cnxn)
app_name = 'dash-sapbusinesswarehousedataplot'

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
app.title = 'CData + Dash'
trace = go.Bar(x=df.CustomerCount, y=df.City, name='CustomerCount')

app.layout = html.Div(children=[html.H1("CData Extension + Dash", style={'textAlign': 'center'}),
	dcc.Graph(
		id='example-graph',
		figure={
			'data': [trace],
			'layout':
			go.Layout(title='SAP Business Warehouse Sales Data', barmode='stack')
		})
], className="container")

if __name__ == '__main__':
    app.run_server(debug=True)