online shopping database design

"click" Off. Hearing this reply, I am not surprised, the heart is just a little disappointed. From the beginning said to do, to the process of learning design, to the final prototype figure out, but also spent a lot of time. Not surprised, because, understand the workflow mechanism, found that to do a perfect point of the better workflow mechanism is very complex, especially to use the work of the module. This complexity may not outweigh the risks of

E-r DesignMany students are learning SQL statements, it is very difficult, it is because you are learning a database you do not know, the table in the database is not designed by you, the relationship between table and table you do not understand. So before learning SQL statements, let's introduce the database design.The following examples illustrate

The origin of the codd RDBMS12 rule--rdbms Edgar Frank Codd (Edgar Frank Code) was hailed as "the father of relational databases" and was awarded the Turing Prize in 1981 for his outstanding contribution to the theory and practice of the database management system. In 1985, Dr. Codd issued 12 rules that succinctly define the concept of a relational database that is used as a

Many of my friends hope that this PDM file can be put on the Internet. I have obtained this file for your learning and hope you can make common progress.Download PDM:/files/wxj1020/sample.rar I attended the advanced database training last week and felt that I had benefited a lot from the high level of speakers. The database design tool uses powerdesigner. This to

Tags: style blog http color AR data SP logI. Overview of the TutorialThis database design tutorial is the author's reference to the online materials, related books, and add their own years of experience in database design related workAccumulate write on.Database

Label:The advantages of the factory method here is not to say, online search a lot of yourself to see If you use the JDBC link database and the database switches from MySQL to Oracle, the change is to switch the name of the driver, and the others do not need to be modified, which is a direct example of factory method flexibility. Empty talk On the code: Public A

Design defects and solutions for CodeIgniter framework database transaction processing, codeigniter framework Cause: In an online business, we use the older CodeIgniter framework. In the DB class, there is a design defect in the processing of DB transactions, maybe it's not a defect. However, it affects our production

be indexed. Avoid applying functions to columns in the WHERE clause: Error:Select service_id, SERVICE_NAMEFrom service_promotionWhere to_char (gmt_modified, 'yyyy-mm-dd ')= '2017-09-01 ';Correct:Select service_id, SERVICE_NAMEFrom service_promotionWhere gmt_modified> = To_date ('2017-9-01 ', 'yyyy-mm-dd ')And gmt_modified Avoid using the automatic type conversion function of the database: Error:Select category_id, category_name from categoryWher

choiceSummarize:Use GUIDs. There is no duplication problem, and data merging is very simple. The association speed is slower than int. It is best to use this scenario for frequently merging data or offline input data online uploads.The GUID value is random and does not accept any form that can be more meaningful to the user. There is no way to determine the order in which the GUID values are generated, so it is not suitable for existing applications

An online 2k game, every second is scary. The traditional hibernate direct plug-in library is basically not feasible. I'm going to deduce a lock-free database operation in one step.1. How to lock in concurrency.A very simple idea to convert concurrency into a single thread. Java's disruptor is a good example. If you use the Java Concurrentcollection class to do, the principle is to start a thread, run a que

DirectoryOverall design processDemand analysisConceptual structure DesignLogical Structure DesignPhysical Design of databaseDatabase implementationDatabase operation and Maintenance Overall design processDatabase Design steps:Design Description:Database design at diffe

", "Sex" and "age" Second, data expansion through the lineThe structure of the user table becomes this way user (Uid,key,value)When the system is online, the data is1 Name Zhang San1 passwd 1232 name John Doe2 passwd 123After the system revision, the data becomes1 Name Zhang San1 passwd 1232 name John Doe2 passwd 1233 name Harry3 passwd 1233 Sex 13 age 18 Advantages:1. Dynamic expansion does not require a lock table2. You can create an index for each

Tags: lucene java database design distributed collectionReprint Please specify source: http://blog.csdn.net/xiaojimanman/article/details/45694049 Http://www.llwjy.com/blogdetail/fa404163e42295646ab6e36e1ddb1037.html Personal Blog Station has been online, the website www.llwjy.com ~ welcome you to vomit Groove ~-----------------------------------------------------

Cause: In one of our lines of business, using the older version of the CodeIgniter framework, which has a design flaw in the DB class, is probably not a flaw. But he has affected our production environment, resulting in a chain reaction. has a greater impact on the business and is not easy to troubleshoot. This question, I in the middle of March this year, once to CodeIgniter China stationmaster Hex Report, after, I also forgot this matter. Until tod

Database design is the most basic part of the whole design1, Django App design: According to the system needs analysis to design Django App,django development is based on the app to develop, so the first step is to design the app.2, the