MYSQL常用函数_MySQL
########### 日期函数 ###########
select now(); -- 当时 yyyy-mm-dd hh:mm:ss
select curdate(); -- 当天 yyyy-mm-dd
select (curdate() - interval (weekday(curdate()) + 1) day); -- 本周第一天
select (curdate() - interval (day(curdate()) - 1) day); -- 本月第一天
select (curdate() - interval (dayofyear(curdate()) - 1) day); -- 本年第一天
select (now() + interval 1 month); -- 下个月今天
select last_day(curdate()); -- 本月最后一天
select last_day(curdate()) + interval 1 day; -- 下月第一天
select date_format('2014-07-08 23:59:59','%Y-%m-%d %H:%i:%s') -- str to date
-- 查找今天的发帖
1. CREATETIME >= date_format(now(),'%Y-%m-%d') and CREATETIME 2. date_format(CREATETIME,'%Y-%m-%d') = LEFT(now(),10)
3. date_format(CREATETIME,'%Y-%m-%d') = date_format(now(),'%Y-%m-%d')
4. CREATETIME like CONCAT(date_format(now(), '%Y-%m-%d'), '%')
5. CREATETIME >= curdate() -- and CREATETIME
UNIX_TIMESTAMP(SUBSTR(FROM_UNIXTIME(r.REPAYMENT_TIME)FROM 1 FOR 10)) UNIX_TIMESTAMP(SUBSTR(NOW()FROM 1 FOR 10))
==>
r.REPAYMENT_TIME and r.REPAYMENT_TIME >= UNIX_TIMESTAMP(curdate() + interval 1 day)
########### 其他函数 ###########
TRUNCATE(X ,D )
ROUND(X ,D )
select 12000/4578, truncate(12000/4578, 10), truncate(12000/4578, 8), round(12000/4578, 8)
IF(expr1,expr2,expr3) --> case when expr1 then expr2 else expr3 end
IFNULL(expr1,expr2) --> case when expr1 is not null then expr1 else expr2 end
CONCAT(str1 ,str2 ,...) --> concat('%', ? '%')
select CONCAT_WS('|', '1','2','3')

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

This article explores optimizing MySQL memory usage in Docker. It discusses monitoring techniques (Docker stats, Performance Schema, external tools) and configuration strategies. These include Docker memory limits, swapping, and cgroups, alongside

This article addresses MySQL's "unable to open shared library" error. The issue stems from MySQL's inability to locate necessary shared libraries (.so/.dll files). Solutions involve verifying library installation via the system's package m

The article discusses using MySQL's ALTER TABLE statement to modify tables, including adding/dropping columns, renaming tables/columns, and changing column data types.

This article compares installing MySQL on Linux directly versus using Podman containers, with/without phpMyAdmin. It details installation steps for each method, emphasizing Podman's advantages in isolation, portability, and reproducibility, but also

This article provides a comprehensive overview of SQLite, a self-contained, serverless relational database. It details SQLite's advantages (simplicity, portability, ease of use) and disadvantages (concurrency limitations, scalability challenges). C

This guide demonstrates installing and managing multiple MySQL versions on macOS using Homebrew. It emphasizes using Homebrew to isolate installations, preventing conflicts. The article details installation, starting/stopping services, and best pra

Article discusses configuring SSL/TLS encryption for MySQL, including certificate generation and verification. Main issue is using self-signed certificates' security implications.[Character count: 159]

Article discusses popular MySQL GUI tools like MySQL Workbench and phpMyAdmin, comparing their features and suitability for beginners and advanced users.[159 characters]
