Blob data from Oracle to text file using python

Blob data from Oracle to text file using python

To extract Blob data from Oracle and save it into a text file using Python, you'll need to use the cx_Oracle library to connect to Oracle and handle Blob data. Here's a step-by-step guide to achieve this:

Step 1: Install Required Libraries

Make sure you have cx_Oracle installed. You can install it via pip if you haven't already:

pip install cx_Oracle

Step 2: Connect to Oracle Database

Use cx_Oracle to connect to your Oracle database. You'll need the Oracle Instant Client and proper configuration (like TNS entries) for connectivity.

import cx_Oracle # Replace with your actual Oracle credentials and connection string username = 'your_username' password = 'your_password' dsn = 'your_dsn' # Oracle TNS name or IP address/port # Establish a connection connection = cx_Oracle.connect(username, password, dsn)

Step 3: Retrieve Blob Data

Assume you have a table in Oracle with Blob data. You can fetch Blob data using cx_Oracle and then write it to a text file.

# SQL query to fetch Blob data sql_query = "SELECT blob_column FROM your_table WHERE your_condition" # Create a cursor cursor = connection.cursor() # Execute the query cursor.execute(sql_query) # Fetch all rows rows = cursor.fetchall() # Loop through rows and process Blob data for row in rows: blob_data = row[0].read() # Read the Blob data # Example: Convert Blob data to string (change encoding as per your Blob content) text_content = blob_data.decode('utf-8') # Write Blob data to a text file with open('output.txt', 'w') as file: file.write(text_content) # Close cursor and connection cursor.close() connection.close()

Explanation

  • Connection: Use cx_Oracle.connect() to establish a connection to your Oracle database. Replace placeholders (username, password, dsn) with your actual credentials and connection details.

  • Query Execution: Execute your SQL query (SELECT blob_column FROM your_table WHERE your_condition) to fetch the Blob data.

  • Fetch and Process: Use cursor.fetchall() to retrieve all rows. Loop through each row, read the Blob data (row[0].read()), and process it as needed. In this example, we assume the Blob data is UTF-8 encoded text (blob_data.decode('utf-8')).

  • Write to File: Write the processed text content (text_content) to a text file (output.txt).

  • Cleanup: Close the cursor (cursor.close()) and the database connection (connection.close()) once done.

Notes

  • Ensure your Oracle environment and permissions allow Blob data retrieval.
  • Handle encoding appropriately based on the actual content of your Blob data.
  • Adjust file handling (open(), write(), etc.) as per your specific requirements for file output.

By following these steps, you can effectively extract Blob data from Oracle using Python with cx_Oracle and save it into a text file. Adjustments may be needed based on your specific database schema and Blob data characteristics.

Examples

  1. "How to fetch Blob data from Oracle database using Python"

    Description: This query demonstrates how to fetch Blob data from an Oracle database using Python and the cx_Oracle library.

    Code:

    import cx_Oracle # Connect to Oracle database connection = cx_Oracle.connect('username', 'password', 'dsn') cursor = connection.cursor() # Query to fetch Blob data cursor.execute("SELECT blob_column FROM my_table WHERE id = :id", id=1) blob_data = cursor.fetchone()[0] # Close connections cursor.close() connection.close()

  2. "How to write Oracle Blob data to a text file in Python"

    Description: This query shows how to write the Blob data fetched from an Oracle database to a text file.

    Code:

    import cx_Oracle # Connect to Oracle database connection = cx_Oracle.connect('username', 'password', 'dsn') cursor = connection.cursor() # Query to fetch Blob data cursor.execute("SELECT blob_column FROM my_table WHERE id = :id", id=1) blob_data = cursor.fetchone()[0] # Write Blob data to a text file with open('output.txt', 'wb') as file: file.write(blob_data.read()) # Close connections cursor.close() connection.close()

  3. "Convert Oracle Blob to text and save in Python"

    Description: This query demonstrates how to convert Blob data to text and save it to a file.

    Code:

    import cx_Oracle # Connect to Oracle database connection = cx_Oracle.connect('username', 'password', 'dsn') cursor = connection.cursor() # Query to fetch Blob data cursor.execute("SELECT blob_column FROM my_table WHERE id = :id", id=1) blob_data = cursor.fetchone()[0] # Read Blob data as text text_data = blob_data.read().decode('utf-8') # Save text data to a file with open('output.txt', 'w') as file: file.write(text_data) # Close connections cursor.close() connection.close()

  4. "Handling large Blob data from Oracle in Python"

    Description: This query explains how to handle and write large Blob data from Oracle to a file in Python.

    Code:

    import cx_Oracle # Connect to Oracle database connection = cx_Oracle.connect('username', 'password', 'dsn') cursor = connection.cursor() # Query to fetch large Blob data cursor.execute("SELECT blob_column FROM my_table WHERE id = :id", id=1) blob_data = cursor.fetchone()[0] # Write large Blob data to a file in chunks with open('large_output.txt', 'wb') as file: while True: chunk = blob_data.read(1024 * 1024) # Read in 1 MB chunks if not chunk: break file.write(chunk) # Close connections cursor.close() connection.close()

  5. "Fetch and save Blob data from Oracle as a binary file using Python"

    Description: This query demonstrates how to fetch Blob data from Oracle and save it as a binary file.

    Code:

    import cx_Oracle # Connect to Oracle database connection = cx_Oracle.connect('username', 'password', 'dsn') cursor = connection.cursor() # Query to fetch Blob data cursor.execute("SELECT blob_column FROM my_table WHERE id = :id", id=1) blob_data = cursor.fetchone()[0] # Save Blob data to a binary file with open('binary_output.bin', 'wb') as file: file.write(blob_data.read()) # Close connections cursor.close() connection.close()

  6. "Read Blob data from Oracle and convert to CSV file using Python"

    Description: This query shows how to read Blob data from Oracle and convert it to a CSV file.

    Code:

    import cx_Oracle import pandas as pd from io import StringIO # Connect to Oracle database connection = cx_Oracle.connect('username', 'password', 'dsn') cursor = connection.cursor() # Query to fetch Blob data cursor.execute("SELECT blob_column FROM my_table WHERE id = :id", id=1) blob_data = cursor.fetchone()[0] # Read Blob data and convert to DataFrame csv_data = blob_data.read().decode('utf-8') df = pd.read_csv(StringIO(csv_data)) # Save DataFrame to CSV file df.to_csv('output.csv', index=False) # Close connections cursor.close() connection.close()

  7. "How to fetch and save Oracle Blob data as a PDF file using Python"

    Description: This query demonstrates how to fetch Blob data from Oracle and save it as a PDF file.

    Code:

    import cx_Oracle # Connect to Oracle database connection = cx_Oracle.connect('username', 'password', 'dsn') cursor = connection.cursor() # Query to fetch Blob data cursor.execute("SELECT blob_column FROM my_table WHERE id = :id", id=1) blob_data = cursor.fetchone()[0] # Save Blob data as PDF file with open('output.pdf', 'wb') as file: file.write(blob_data.read()) # Close connections cursor.close() connection.close()

  8. "Save Oracle Blob data to an image file using Python"

    Description: This query shows how to save Blob data from Oracle as an image file.

    Code:

    import cx_Oracle # Connect to Oracle database connection = cx_Oracle.connect('username', 'password', 'dsn') cursor = connection.cursor() # Query to fetch Blob data cursor.execute("SELECT blob_column FROM my_table WHERE id = :id", id=1) blob_data = cursor.fetchone()[0] # Save Blob data as an image file with open('output_image.png', 'wb') as file: file.write(blob_data.read()) # Close connections cursor.close() connection.close()

  9. "Extract and save XML data from Oracle Blob to a file using Python"

    Description: This query demonstrates how to extract XML data from a Blob and save it to a file.

    Code:

    import cx_Oracle # Connect to Oracle database connection = cx_Oracle.connect('username', 'password', 'dsn') cursor = connection.cursor() # Query to fetch Blob data cursor.execute("SELECT blob_column FROM my_table WHERE id = :id", id=1) blob_data = cursor.fetchone()[0] # Read Blob data and save as XML file xml_data = blob_data.read().decode('utf-8') with open('output.xml', 'w') as file: file.write(xml_data) # Close connections cursor.close() connection.close()

  10. "Fetch and save audio Blob data from Oracle to a file using Python"

    Description: This query explains how to fetch and save audio data stored as a Blob in Oracle.

    Code:

    import cx_Oracle # Connect to Oracle database connection = cx_Oracle.connect('username', 'password', 'dsn') cursor = connection.cursor() # Query to fetch Blob data cursor.execute("SELECT blob_column FROM my_table WHERE id = :id", id=1) blob_data = cursor.fetchone()[0] # Save Blob data as an audio file with open('output_audio.wav', 'wb') as file: file.write(blob_data.read()) # Close connections cursor.close() connection.close()

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