


MySQL transaction processing: the difference between automatic submission and manual submission
Mar 16, 2024 am 11:33 AMMySQL transaction processing: the difference between automatic submission and manual submission
In the MySQL database, a transaction is a set of SQL statements, either all executed successfully, or all Execution fails, ensuring data consistency and integrity. In MySQL, transactions can be divided into automatic submission and manual submission. The difference lies in the timing of transaction submission and the scope of control over the transaction. The following will introduce the difference between automatic submission and manual submission in detail, and give specific code examples to illustrate.
1. Automatic submission
In MySQL, if transaction processing is not explicitly enabled, each SQL statement will be automatically submitted. In other words, the transaction will be automatically submitted after each SQL statement is executed, and the data modification will take effect immediately, so the consistency of the data cannot be guaranteed.
By default, the auto-commit function is automatically enabled in MySQL. You can control the behavior of automatic submission by setting the autocommit parameter. When autocommit is 1, it means automatic submission is enabled; when autocommit is 0, it means automatic submission is disabled.
The following is a simple code example that demonstrates the behavior of automatic submission:
CREATE TABLE example_table ( id INT PRIMARY KEY, name VARCHAR(50) ); INSERT INTO example_table VALUES (1, 'Alice'); INSERT INTO example_table VALUES (2, 'Bob'); SELECT * FROM example_table;
After the above code is executed, the data will be automatically submitted, and the data modification will take effect immediately.
2. Manual submission
Manual submission refers to executing multiple SQL statements within a transaction and then manually submitting the transaction at the appropriate time to ensure data consistency. In MySQL, you can use the BEGIN, COMMIT, and ROLLBACK statements to control the commit and rollback of transactions.
The following is a sample code that demonstrates the behavior of manual submission:
SET autocommit = 0; -- Turn off automatic submission BEGIN; -- Start transaction UPDATE example_table SET name = 'Alice Smith' WHERE id = 1; DELETE FROM example_table WHERE id = 2; SELECT * FROM example_table; -- The data has not yet been submitted and the query results do not contain the latest modifications. COMMIT; -- Commit the transaction SELECT * FROM example_table; -- At this time, the data has been submitted, and the query results include the latest modifications
In the above code, manual submission disables automatic submission by setting autocommit to 0, and then uses BEGIN to start the transaction and execute multiple SQL statement, and finally use COMMIT to commit the transaction. During the manual submission process, you can use ROLLBACK at any time to roll back the transaction and undo previous modifications. This ensures data consistency and integrity.
Summary:
Automatic submission and manual submission are two ways of transaction processing in MySQL. The difference lies in the timing and control method of transaction submission. Autocommit automatically commits the transaction after each SQL statement is executed, while manual commit requires explicitly starting and ending the transaction. In actual applications, choose the appropriate submission method as needed to ensure data consistency and integrity.
The above is the detailed content of MySQL transaction processing: the difference between automatic submission and manual submission. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

To add MySQL's bin directory to the system PATH, it needs to be configured according to the different operating systems. 1. Windows system: Find the bin folder in the MySQL installation directory (the default path is usually C:\ProgramFiles\MySQL\MySQLServerX.X\bin), right-click "This Computer" → "Properties" → "Advanced System Settings" → "Environment Variables", select Path in "System Variables" and edit it, add the MySQLbin path, save it and restart the command prompt and enter mysql--version verification; 2.macOS and Linux systems: Bash users edit ~/.bashrc or ~/.bash_

The key steps for installing MySQL on Windows 11 are as follows: 1. Download the correct version, select the Windows MSI installation package and ensure that the system is 64-bit; 2. Select the "Custom" mode during installation, add MySQLServer and set the appropriate installation path; 3. Run the configuration wizard, select the "ServerComputer" configuration type, set the root password, and select the automatic startup method; 4. After the test installation is successful, if the prompt command is unavailable, add the MySQL bin directory to the system PATH environment variable. Follow these steps to complete the installation and configuration smoothly.

To reset the root password of MySQL, please follow the following steps: 1. Stop the MySQL server, use sudosystemctlstopmysql or sudosystemctlstopmysqld; 2. Start MySQL in --skip-grant-tables mode, execute sudomysqld-skip-grant-tables&; 3. Log in to MySQL and execute the corresponding SQL command to modify the password according to the version, such as FLUSHPRIVILEGES;ALTERUSER'root'@'localhost'IDENTIFIEDBY'your_new

When handling NULL values ??in MySQL, please note: 1. When designing the table, the key fields are set to NOTNULL, and optional fields are allowed NULL; 2. ISNULL or ISNOTNULL must be used with = or !=; 3. IFNULL or COALESCE functions can be used to replace the display default values; 4. Be cautious when using NULL values ??directly when inserting or updating, and pay attention to the data source and ORM framework processing methods. NULL represents an unknown value and does not equal any value, including itself. Therefore, be careful when querying, counting, and connecting tables to avoid missing data or logical errors. Rational use of functions and constraints can effectively reduce interference caused by NULL.

Turn on MySQL slow query logs and analyze locationable performance issues. 1. Edit the configuration file or dynamically set slow_query_log and long_query_time; 2. The log contains key fields such as Query_time, Lock_time, Rows_examined to assist in judging efficiency bottlenecks; 3. Use mysqldumpslow or pt-query-digest tools to efficiently analyze logs; 4. Optimization suggestions include adding indexes, avoiding SELECT*, splitting complex queries, etc. For example, adding an index to user_id can significantly reduce the number of scanned rows and improve query efficiency.

mysqldump is a common tool for performing logical backups of MySQL databases. It generates SQL files containing CREATE and INSERT statements to rebuild the database. 1. It does not back up the original file, but converts the database structure and content into portable SQL commands; 2. It is suitable for small databases or selective recovery, and is not suitable for fast recovery of TB-level data; 3. Common options include --single-transaction, --databases, --all-databases, --routines, etc.; 4. Use mysql command to import during recovery, and can turn off foreign key checks to improve speed; 5. It is recommended to test backup regularly, use compression, and automatic adjustment.

TosecurelyconnecttoaremoteMySQLserver,useSSHtunneling,configureMySQLforremoteaccess,setfirewallrules,andconsiderSSLencryption.First,establishanSSHtunnelwithssh-L3307:localhost:3306user@remote-server-Nandconnectviamysql-h127.0.0.1-P3307.Second,editMyS

MySQL paging is commonly implemented using LIMIT and OFFSET, but its performance is poor under large data volume. 1. LIMIT controls the number of each page, OFFSET controls the starting position, and the syntax is LIMITNOFFSETM; 2. Performance problems are caused by excessive records and discarding OFFSET scans, resulting in low efficiency; 3. Optimization suggestions include using cursor paging, index acceleration, and lazy loading; 4. Cursor paging locates the starting point of the next page through the unique value of the last record of the previous page, avoiding OFFSET, which is suitable for "next page" operation, and is not suitable for random jumps.
