The difference between Datetime and Timestamp in Mysql
The three types of date, datetime, and timestamp (if you count int, four types) used to represent time in mysql are relatively easy to confuse. Let’s compare the similarities and differences of these three types
Same points
Both can be used to represent time
Both are displayed as strings
Different points
1. As the name suggests, date only represents the date in the form of 'YYYY-MM-DD', datetime represents 'YYYY-MM-DD'
Date plus time in the form of HH:mm:ss', timestamp is displayed in the same format as datetime.
2. The time range that date and datetime can represent is '1000-01-01' to '9999-12-31'. Timestamp can represent '1970-01-01 due to the limitation of the 32-bit int type.
00:00:01'to'2038-01-19
03:14:07' UTC time.
3. Mysql will convert the time to UTC time when storing the timestamp type, and then restore it to the current time zone when reading.
If you store a timestamp type value and then modify the MySQL time zone, you will get an incorrect time when you read the value again. This does not happen with date and datetime.
4. The timestamp type provides the automatic update function, you only need to set its default value to CURRENT_TIMESTAMP.
5. Except that date is kept to the day, datetime and timestamp are both kept to the second, and milliseconds are ignored.
Time format
mysql provides a relatively loose time string format for addition, deletion, modification and query. Refer to the iso time format, which is generally written as '2013-06-05 16:34:18'. But you can also abbreviate it as '13-6-5', but this can easily cause confusion. For example, mysql will also treat '13:6:5' as the year, month and day, and when '13:16:5' form, mysql considers it to be an incorrect format, a warning will be given, and then the value stored in the database is '0000-00-00 00:00:00'.
The manual also specifically mentions a situation, that is, when the value of the current year is 0~69, mysql considers it to be 2000~2069, and when 70~99, it considers it to be 1970~1999. I feel like it's superfluous.
In short, if you stay the same and adapt to the ever-changing situation, you can always use the 'YYYY-MM-DD HH:mm:ss' format.
The above is the detailed content of The difference between Datetime and Timestamp in Mysql. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

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

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

Undress AI Tool
Undress images for free

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











The main role of MySQL in web applications is to store and manage data. 1.MySQL efficiently processes user information, product catalogs, transaction records and other data. 2. Through SQL query, developers can extract information from the database to generate dynamic content. 3.MySQL works based on the client-server model to ensure acceptable query speed.

The process of starting MySQL in Docker consists of the following steps: Pull the MySQL image to create and start the container, set the root user password, and map the port verification connection Create the database and the user grants all permissions to the database

Laravel is a PHP framework for easy building of web applications. It provides a range of powerful features including: Installation: Install the Laravel CLI globally with Composer and create applications in the project directory. Routing: Define the relationship between the URL and the handler in routes/web.php. View: Create a view in resources/views to render the application's interface. Database Integration: Provides out-of-the-box integration with databases such as MySQL and uses migration to create and modify tables. Model and Controller: The model represents the database entity and the controller processes HTTP requests.

I encountered a tricky problem when developing a small application: the need to quickly integrate a lightweight database operation library. After trying multiple libraries, I found that they either have too much functionality or are not very compatible. Eventually, I found minii/db, a simplified version based on Yii2 that solved my problem perfectly.

The key to installing MySQL elegantly is to add the official MySQL repository. The specific steps are as follows: Download the MySQL official GPG key to prevent phishing attacks. Add MySQL repository file: rpm -Uvh https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm Update yum repository cache: yum update installation MySQL: yum install mysql-server startup MySQL service: systemctl start mysqld set up booting

Article summary: This article provides detailed step-by-step instructions to guide readers on how to easily install the Laravel framework. Laravel is a powerful PHP framework that speeds up the development process of web applications. This tutorial covers the installation process from system requirements to configuring databases and setting up routing. By following these steps, readers can quickly and efficiently lay a solid foundation for their Laravel project.

MySQL and phpMyAdmin are powerful database management tools. 1) MySQL is used to create databases and tables, and to execute DML and SQL queries. 2) phpMyAdmin provides an intuitive interface for database management, table structure management, data operations and user permission management.

Installing MySQL on CentOS involves the following steps: Adding the appropriate MySQL yum source. Execute the yum install mysql-server command to install the MySQL server. Use the mysql_secure_installation command to make security settings, such as setting the root user password. Customize the MySQL configuration file as needed. Tune MySQL parameters and optimize databases for performance.
