Transaction operations and automatic submission mechanism in MySQL database

Transaction operations and automatic submission mechanism in MySQL database

In the database system, a transaction refers to a set of database operations, which are either all executed successfully , or all fail and roll back to the state before the transaction started. MySQL database is a commonly used relational database management system that supports transaction operations and transaction control. In MySQL, an important concept is the automatic commit mechanism. When the auto-commit mechanism is turned on, each SQL statement will be treated as a transaction and the commit operation will be performed immediately; conversely, when the auto-commit mechanism is turned off, you need to manually control the commit or rollback of the transaction.

The following will introduce the specific content of transaction operations and automatic submission mechanism in MySQL database, and attach code examples.

1. Turn on and off the automatic submission mechanism

In MySQL, you can use the following statement to turn on or off the automatic submission mechanism:

-- Turn on automatic submit
SET autocommit = 1;

-- Turn off automatic submission
SET autocommit = 0;

2. Manually control transaction operations

When the autocommit mechanism is turned off, you can use the following statements to manually control the commit and rollback of transactions:

-- Start transaction
START TRANSACTION;

-- Submit transaction
COMMIT;

--Rollback transaction
ROLLBACK;

3. Transaction Operation Example

Next, we will use a simple example to demonstrate the specific process of transaction operation. Suppose we have a table named students, containing two fields id and name.

First, create the table students:

CREATE TABLE students (
    id INT PRIMARY KEY,
    name VARCHAR(50)
);

Then, insert a record and turn off automatic submission:

-- Turn off automatic submission
SET autocommit = 0;

-- Start transaction
START TRANSACTION;

--Insert record
INSERT INTO students VALUES (1, 'Alice');

Then, insert a record again:

INSERT INTO students VALUES (2, 'Bob');

This When , you can choose to commit the transaction or rollback the transaction:

-- Commit the transaction
COMMIT;

-- Or rollback the transaction
ROLLBACK;

Through the above example, we can see the basic flow of transaction operations and how to manually control the commit and rollback of transactions. In practical applications, transaction operations can ensure data integrity and consistency, which is especially important when multiple operations are involved.

The above is an introduction to the transaction operation and automatic submission mechanism in the MySQL database. I hope it will be helpful to you.

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