We will create two new tables: accounts and account_changes for the demonstration. If you do not want to save the changes, you can roll back using the ROLLBACK or ROLLBACK TRANSACTION statement: ROLLBACK Code language: SQL (Structured Query Language) ( sql ) SQLite transaction example COMMIT Code language: SQL (Structured Query Language) ( sql ) Third, commit the changes to the database by using the COMMIT or COMMIT TRANSACTION statement. Note that the change is only visible to the current session (or client).
#Python sqlite transaction update#
Second, issue SQL statements to select or update data in the database. BEGIN TRANSACTION Code language: SQL (Structured Query Language) ( sql )Īfter executing the statement BEGIN TRANSACTION, the transaction is open until it is explicitly committed or rolled back. To start a transaction explicitly, you use the following steps:įirst, open a transaction by issuing the BEGIN TRANSACTION command. It means that for each command, SQLite starts, processes, and commits the transaction automatically. On the contrary, if the program crashes before the transaction is committed, the change should not persist.īy default, SQLite operates in auto-commit mode. Durable: if a transaction is successfully committed, the changes must be permanent in the database regardless of the condition such as power failure or program crash.On the other hand, the changes committed by other sessions after the transaction started should not be visible to the current session. When a session starts a transaction and executes the INSERT or UPDATE statement to change the data, these changes are only visible to the current session, not others. Isolation: a pending transaction performed by a session must be isolated from other sessions.However, when the transaction is committed or rolled back, it is important that the transaction must keep the database consistent.
When a transaction starts and executes a statement to modify data, the database becomes inconsistent. Consistent: a transaction must ensure to change the database from one valid state to another.When you commit a transaction, either the entire transaction is applied or not. It means that a change cannot be broken down into smaller ones. Atomic: a transaction should be atomic.SQLite guarantees all the transactions are ACID compliant even if the transaction is interrupted by a program crash, operation system dump, or power failure to the computer. SQLite is a transactional database that all changes and queries are atomic, consistent, isolated, and durable (ACID).
#Python sqlite transaction how to#
Summary: in this tutorial, we will show you how to use the SQLite transaction to ensure the integrity and reliability of the data.
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