Short code example on how to read data from an Oracle database into a Pandas Dataframe using cx_Oracle

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Python Development Example
Read data from Oracle Database into Pandas DataFrame
Johan Louwers – Chief Customer Architect @ Oracle
Version : Feb 2019
@johanlouwers
Johanlouwers.blogspot.com
Oracle Confidential – Internal/Restricted/Highly Restricted

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Python Development
with pandas and CX_Oracle
Slide-deck Intention :
• This presentation is intended to provide
a quick introduction example on how to
load data from an Oracle Database into
pandas.
• This example is a part of a wider
workshop deck and shared as a stand-
alone example for ease of sharing.
• The code should only be used as an
educational example and is not
intended to be included in any real-
world application code.
3
Contact details :
Johan Louwers - Chief Customer Architect
@johanlouwers
Johan.louwers@oracle.com
github.com/louwersj
Johanlouwers.blogspot.com

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Python Development
Pandas – read data from database into DataFrame
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pd.read_sql
What do we want to achieve?
1) Read data from an Oracle database into a DataFrame based upon a SQL query.
2) We use cx_Oracle in combination with Oracle Database 18c

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import pandas as pd
import cx_Oracle
orclUserName = 'pandas_test'
orclPassword = 'pandas_test'
orclHost = '192.168.33.10'
orclPort = '1521'
orclServiceName = 'pdb1'
dsn = cx_Oracle.makedsn(host=orclHost,
port=orclPort,
sid=None,
service_name=orclServiceName
)
connection = cx_Oracle.connect(user=orclUserName,
password=orclPassword,
dsn=dsn,
encoding="UTF-8",
nencoding="UTF-8"
)
query = """SELECT * FROM emp"""
df_ora = pd.read_sql(query, con=connection)
print (df_ora.head())
Import
cx_Oracle
Provide needed
details
Define the Data
Source Name
Define the
connection
Define the
query
Execute the
read_sql()
Python Development
Pandas – read data from database into DataFrame

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Show me the output
1) You can verify the output of df_ora.head() with the content of your database EMP table
Python Development
Pandas – read data from database into DataFrame

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