Database Table Inheritance

Single-table policy: This is the default policy in the inheritance map, which is mapped using this mapping strategy, not specifically specified. The mapping principle for this policy is that the parent class, including the newly added attributes in the subclass, is mapped to a database table, and an automatically generated field in the database table is used to store information that distinguishes the different subclasses. Joined-subclass policy: In this mapping strategy, each entity class in the inheritance relationship, whether specific class (concrete entity) or abstract ...

This series of articles is a learning record about the fundamentals of azure services development, and because of time constraints, the process of wishing to discuss and explore yourself is from scratch, to be able to develop basic programming for azure services. There may be a very deep topic relative to each topic, and I would like to have time to do it through other articles. 　　The positioning of this series is basically positioning, take 20-30 minutes, download the code first, follow the article, run to get the relevant experience. The previous article is about Azure queue storage, this is about ...

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This is a UI template specification, B / S version of the application is more applicable, in fact, such a thing is not what the formal norms, just to adapt to the development environment we are now facing and organizational processes to make some expeditious efforts , And to solve some problems with the program communication and interface, try to avoid misunderstanding and friction. First, the applicable environment and object Second, the necessity Third, the technical principles Fourth, the code writing norms Fifth, the page template specification First, the applicable environment and objects This specification applies to browser-based B / S version of the software project development. Template development process template page writing and template files apply ...

Databases are the basis of E-commerce, finance, and ERP systems, and often hold important business partners and customer information. Electronic data from most businesses, organizations, and government departments are kept in various databases, where they keep personal data and sensitive financial data. But databases are often not as secure as operating systems and networks. Data is the lifeblood of an organization, so it is critical to choose a secure database. I installed the MSSQL and MySQL by default with admin account on my machine to be in the same ...

Related Settings for IIS: Delete the default site's virtual directory, stop the default Web site, delete the corresponding file directory c:inetpub, configure the public settings for all sites, set the associated number of connections, bandwidth settings, and other settings such as performance settings. Configures application mappings, removes all unnecessary application extensions, and retains only asp,php,cgi,pl,aspx application extensions. For PHP and CGI, it is recommended to use ISAPI parsing and EXE parsing to have an impact on security and performance. User program debug Settings send ...

Simple mapping is one of the simplest and most basic of object-relational mapping, so learning simple mapping is the prerequisite of mastering inheritance mapping and relational mapping. In recent years ORM (Object-relational Mapping, Object-relational mapping, that is, the mapping of entity objects and database tables) technology market is very lively, a variety of persistent framework came into being, the most influential is the Hibernate and TopLink. Sun is fully absorbing existing excellent ORM especially hibern ...

"HBase Authority Guide" in-depth study one: Know hbase blog Category: Hbasehadoop hbasehadoopnosql One, hbase what? First of all, HBase is a distributed database of NoSQL in the HDFS distributed storage System of Hadoop, which has the following characteristics: 1, provide random, real-time read-write query, by ...

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Pomm is a lightweight, fast, efficient and powerful PHP object management for postgresqlhttp://www.aliyun.com/zixun/aggregation/22.html "> relational Database model." Pomm generates code work from its speed and its rich feature settings with PostgreSQL benefits. It uses SQL as the query language because it is often the orms used by developers, making it easier to optimize queries directly. This also allows developers to ...