Database design four major design patterns of the general principles of use
1. The main expansion mode
Main expansion mode is usually used to extract several similar attributes of the object up to form a "common attribute table", and "Public property sheet" and "exclusive property sheet" relationship "one to one".
"Exclusive property sheet" can be seen as an extension of "common attribute table", and the two together is a complete description of a particular object, so named "main expansion mode."
Number of small objects; between the respective properties of the object have some differences; attribute of each object can be completely determined at the design stage of the database; extended object has a separate individual, relatively complex business processing requirements, this time with the "main expansion mode". The common attributes of each extracted object designed as a "master table", and the remaining attributes of each object are designed a corresponding "extended," and "master" table and each "extension table", respectively, to establish one to one relationship.
2. The master-slave mode
Master-slave mode, database design pattern is the most common and most of all a model used in the everyday design work, he described the master-slave relationship between the two tables, is typical of many relationship.
The large number of objects and not fixed; property between the respective objects is little difference; attributes of the object can be completely determined at the design stage of the database; individual objects no independent business processing requirements, this time with the "master-slave mode." The design of each object relationship with the "main table" build-to-many objects "from the table" records.
3. Name Value mode
Name-value mode, often used to describe the properties can not be fully determined in the system design phase objects, properties of those objects will be greatly changed while the system is running, or there is a big difference between the properties of objects.
Extremely large number of objects; between the respective properties of the object are quite different; the database object properties can not be determined at the design stage, or a greater change in the system is running; each business object does not have independent processing requirements, this time with "name-value model."
4. many-mode
To-many mode, is relatively common kind of database design pattern, primary and secondary portions of two objects, such as the status of what he described many relationship to each other.
To-many modes need to establish a correlation table between two tables, the table is the core of this association many relationships.
Mutually-many relationship between two objects, use the "many to many models."
Database design four major design patterns of the general principles of use
1. The main expansion mode
Main expansion mode is usually used to extract several similar attributes of the object up to form a "common attribute table", and "Public property sheet" and "exclusive property sheet" relationship "one to one".
"Exclusive property sheet" can be seen as an extension of "common attribute table", and the two together is a complete description of a particular object, so named "main expansion mode."
Number of small objects; between the respective properties of the object have some differences; attribute of each object can be completely determined at the design stage of the database; extended object has a separate individual, relatively complex business processing requirements, this time with the "main expansion mode". The common attributes of each extracted object designed as a "master table", and the remaining attributes of each object are designed a corresponding "extended," and "master" table and each "extension table", respectively, to establish one to one relationship.
2. The master-slave mode
Master-slave mode, database design pattern is the most common and most of all a model used in the everyday design work, he described the master-slave relationship between the two tables, is typical of many relationship.
The large number of objects and not fixed; property between the respective objects is little difference; attributes of the object can be completely determined at the design stage of the database; individual objects no independent business processing requirements, this time with the "master-slave mode." The design of each object relationship with the "main table" build-to-many objects "from the table" records.
3. Name Value mode
Name-value mode, often used to describe the properties can not be fully determined in the system design phase objects, properties of those objects will be greatly changed while the system is running, or there is a big difference between the properties of objects.
Extremely large number of objects; between the respective properties of the object are quite different; the database object properties can not be determined at the design stage, or a greater change in the system is running; each business object does not have independent processing requirements, this time with "name-value model."
4. many-mode
To-many mode, is relatively common kind of database design pattern, primary and secondary portions of two objects, such as the status of what he described many relationship to each other.
To-many modes need to establish a correlation table between two tables, the table is the core of this association many relationships.
Mutually-many relationship between two objects, use the "many to many models."