Performing Database Transactions using Python
Transactions are a mechanism that ensures data consistency. Transactions have the following four properties −
- Atomicity − Either a transaction completes or nothing happens at all.
- Consistency − A transaction must start in a consistent state and leave the system in a consistent state.
- Isolation − Intermediate results of a transaction are not visible outside the current transaction.
- Durability − Once a transaction was committed, the effects are persistent, even after a system failure.
The Python DB API 2.0 provides two methods to either commit or rollback a transaction.
Example
You already know how to implement transactions. Here is again similar example −
# Prepare SQL query to DELETE required records
sql = "DELETE FROM EMPLOYEE WHERE AGE > '%d'" % (20)
try:
# Execute the SQL command
cursor.execute(sql)
# Commit your changes in the database
db.commit()
except:
# Rollback in case there is any error
db.rollback()
Published on 31-Jan-2020 14:31:40
