database table design best practices

, but only attributes. to describe a real-world student, you first need a model class of Student. For example, the class name is called student, which is used to save the unique information of each student, such as the name. then, describe the behavior in the business logic layer. For example, create a studentbl class in the business logic layer and add a walk () method to it. currently, it is quite popular to use business models to design systems. Bu

Tags: a primary table nbsp FOREIGN key constraint learning one-to-one IMG sample groomingTo do a project, must be the database design! In the learning stage, the basic is a single table. However, in the actual development process, one-to-many, many-to-many tables everywhere! Simple collation, one-to-many, many-to-many

2010-01-02, but the actual release time was slightly early 2009-12-31.You are confidently typing with confidence:UPDATE NEWS2010 　　 SET = ' 2009-12-31 ' WHERE = 12345　　At run time, suddenly think, this data becomes an invalid data, it should be deposited in NEWS2009 this table. Update is useless, you must add it to the NEWS2010 and then delete this piece of data.　　4. To ensure uniquenessThe split data, whose primary key is unique in the

Specifically, it isThe database has such a tableAccount0Account1Account2Account3Every table, if it's 10,000 players,sprintf (M_szsql, "UPDATE account%d SET Rmcard=rmcard +%lld,coin=coin +%lld,safecoin=safecoin +%lld where uid=%d;",Ccommonlogic::getdatatablenum (UID), roomcard,coin,safecoin,uid);This is the design of the sub-tableUInt32 ccommonlogic::getdatatablen

contact types can be linked to.In the Contact_mech, there is a field called info_string, if the Contact_mech represents an email, then info_string content is email, but if this contact_ Mech represents the phone number or address, where to store the area code, city, zip code and other content? Obviously, OFBiz will not put all this information peremptorily into a string into the info_string, so that there must be two other tables: Telecom_number (storage phone number) and postal_address (storag

system already exists, the design of this simple writing can be really simple. There are two similar practices in "loosely coupled programming. One is that the master tells his thoughts to the apprentice (generally using a whiteboard or blank paper), and the apprentice asks the teacher to answer questions, almost until now. On the contrary, the apprentice told the master about the question and guidance of

Tree structure-tree structure data storage and database table designTree structure is generally used in the infinite class classification, whether you use Java,.net,php,python and other language platforms for development and application, tree-shaped structure is a very common structural design.This paper mainly solves the tree structure data storage and database

Label:After you modify the table design for a SQL Server 2012 database, the following error message appears when you save the table design:saving changes is not allowed. Your changes require that the following tables be deleted and recreated. You have made changes to the label that cannot be recreated or enabled the "P

Description Id Int Primary_key auto_increment Date Date user_id Int FOREIGN KEY (The provider of the answer, corresponding to the ID field in the user table) User_type Int (Judge that the user is a student, teacher or TA, teacher: 0, TA: 1, Student: 2) Content varchar (1024) Num_vote Int

binary relationship. Database types include Oracle, MS SQL, Mysql, Nosql, Sybase, Infomix, DB2, VF, Access and other database types, the life cycle of a database system can be divided: three stages: design, development, and product creation. The lowest cost and maximum benefit of