订单表和订单号的问题
做一个订单表，如下
orderid //主键
customerid //用户号
productid //产品号
num //数量
price //价格
...
如果把订单号作为主键的话，一般买东西都是买很多种类，不同数量，我这么做的表一行只能记录一种产品的情况，如果多种产品，应该都属于同一个订单号，但是订单号是主键，不允许重复，那怎么解决？
------解决方案--------------------
做一个表保存每个订单的东西啊。其中的orderid可以作为外键和你整个表对应。
你从3NF开始看起吧……
Fujifilm X-M5 price expectations rise as leaked selfie display adds complexity to the formerly affordable camera lineSep 07, 2024 am 09:34 AMFujifilm fans were recently very excited at the prospect of the X-T50, since it presented a relaunch of the budget-oriented Fujifilm X-T30 II that had become quite popular in the sub-$1,000 APS-C category. Unfortunately, as the Fujifilm X-T50's launc
FiiO CP13 cassette player launches with transparent retro lookJun 16, 2024 am 09:52 AMTheFiiOCP13cassetteplayerwasannouncedinJanuary.Now,FiiOisexpandingitsportfoliowithtwonewmodels-onewitharedfrontandonewithatransparentfront.Thelatternotonlyperfectlymatchestheretrocharmoftheangulardesign,butalso
Klipsch unveils Flexus Core 300 flagship soundbar with 8K support, 12 speakers and room correctionSep 05, 2024 am 10:16 AMThe Klipsch Flexus Core 300 is the top model in the series and is positioned above the already available Flexus Core 200 in the company's soundbar line-up. According to Klipsch, this is the first soundbar in the world whose sound can be adapted to th
Light Phone 3 launches with 50% discount, monochrome OLED and minimalist designJun 13, 2024 pm 10:18 PMWhiletheLightPhone2from2018wasstillequippedwithaneconomicale-inkdisplay,theLightPhone3usesanOLEDdisplaythatcanonlydisplaygrayscale.Thereasonfortheswitchtothe3.92-inchOLEDpanelwithitsresolutionof1,240x1,080isth
Deal | Tesla Model 3 Long Range AWD regains full $7,500 tax incentive, drops to below $40,000Jun 19, 2024 am 09:55 AMShortly after Tesla launched the Model 3 Highland refresh towards the end of last year, the US federal EV tax incentive rules changed, cutting the potential discount in half for eligible buyers because of Tesla's use of Chinese LFP cells in the new M
Realme Pad 2 Lite: Affordable tablet launches with quad speakers, 90 Hz display and 15h battery lifeSep 14, 2024 am 06:28 AMMore than a year after the launch of the Realme Pad 2 the manufacturer presents the more affordable Realme Pad 2 Lite. The new model is slightly smaller, as the display shrinks from 11.5 inches to 10.95 inches, with the IPS panel achieving a resoluti
Tipster claims Snapdragon 8 Gen 4 costs nearly 21% more than its predecessorSep 09, 2024 am 06:35 AMThere have been multiple reports about Qualcomm increasing the price of Snapdragon 8 Gen 4 compared to its current-gen flagship SoC. Digital Chat Station, a notable leakster, reported about it back in May, which was later reinforced with a separate r
\'Friend\' launches as creepy AI gadget that could be straight out of Black MirrorJul 31, 2024 pm 07:57 PMFriend, a brand new AI gadget that does away with a display altogether, is now available. The hardware is very simple: Friend is a flat, round device that is attached to a necklace and has both integrated microphones and a touch-sensitive surface on
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
Dreamweaver Mac version
Visual web development tools
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool
SublimeText3 Chinese version
Chinese version, very easy to use
MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
