MySQL: ON DUPLICATE KEY UPDATE 用法
使用该语法可在插入记录的时候先判断记录是否存在，如果不存在则插入，否则更新，很方便，无需执行两条SQL 无 INSERT INTO osc_visit_stats(stat_date,type,id,view_count) VALUES (?,?,?,?) ON DUPLICATE KEY UPDATE view_count=view_count+?-- osc_visit_st
使用该语法可在插入记录的时候先判断记录是否存在，如果不存在则插入，否则更新，很方便，无需执行两条SQLINSERT INTO osc_visit_stats(stat_date,type,id,view_count) VALUES (?,?,?,?) ON DUPLICATE KEY UPDATE view_count=view_count+? -- osc_visit_stats 表有复合主键 (stat_date,type,id)
INSERT INTO osc_space_visit_records(space,user,visit_count,ip,visit_time) VALUES(?,?,?,?,?) ON DUPLICATE KEY UPDATE visit_count=visit_count+1,ip=?,visit_time=NOW()
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
AI Hentai Generator
Generate AI Hentai for free.
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
How to optimize MySQL query performance in PHP?
Jun 03, 2024 pm 08:11 PM
MySQL query performance can be optimized by building indexes that reduce lookup time from linear complexity to logarithmic complexity. Use PreparedStatements to prevent SQL injection and improve query performance. Limit query results and reduce the amount of data processed by the server. Optimize join queries, including using appropriate join types, creating indexes, and considering using subqueries. Analyze queries to identify bottlenecks; use caching to reduce database load; optimize PHP code to minimize overhead.
How to use MySQL backup and restore in PHP?
Jun 03, 2024 pm 12:19 PM
Backing up and restoring a MySQL database in PHP can be achieved by following these steps: Back up the database: Use the mysqldump command to dump the database into a SQL file. Restore database: Use the mysql command to restore the database from SQL files.
How to insert data into a MySQL table using PHP?
Jun 02, 2024 pm 02:26 PM
How to insert data into MySQL table? Connect to the database: Use mysqli to establish a connection to the database. Prepare the SQL query: Write an INSERT statement to specify the columns and values to be inserted. Execute query: Use the query() method to execute the insertion query. If successful, a confirmation message will be output.
How to fix mysql_native_password not loaded errors on MySQL 8.4
Dec 09, 2024 am 11:42 AM
One of the major changes introduced in MySQL 8.4 (the latest LTS release as of 2024) is that the "MySQL Native Password" plugin is no longer enabled by default. Further, MySQL 9.0 removes this plugin completely. This change affects PHP and other app
Unpatchable Yubico two-factor authentication key vulnerability breaks the security of most Yubikey 5, Security Key, and YubiHSM 2FA devices
Sep 04, 2024 pm 06:32 PM
An unpatchable Yubico two-factor authentication key vulnerability has broken the security of most Yubikey 5, Security Key, and YubiHSM 2FA devices. The Feitian A22 JavaCard and other devices using Infineon SLB96xx series TPMs are also vulnerable.All
How to use MySQL stored procedures in PHP?
Jun 02, 2024 pm 02:13 PM
To use MySQL stored procedures in PHP: Use PDO or the MySQLi extension to connect to a MySQL database. Prepare the statement to call the stored procedure. Execute the stored procedure. Process the result set (if the stored procedure returns results). Close the database connection.
KDE Plasma 6.1 brings many enhancements to the popular Linux desktop
Jun 23, 2024 am 07:54 AM
After several pre-releases, the KDE Plasma development team unveiled version 6.0 of its desktop environment for Linux and BSD systems on 28 February, using the Qt6 framework for the first time. KDE Plasma 6.1 now comes with a number of new features t
How to create a MySQL table using PHP?
Jun 04, 2024 pm 01:57 PM
Creating a MySQL table using PHP requires the following steps: Connect to the database. Create the database if it does not exist. Select a database. Create table. Execute the query. Close the connection.
