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Data Access Object
In software, a data access object (DAO) is a pattern that provides an abstract interface to some type of database or other persistence mechanism. By mapping application calls to the persistence layer, the DAO provides data operations without exposing database details. This isolation supports the single responsibility principle. It separates the data access the application needs, in terms of domain-specific objects and data types (the DAO's public interface), from how these needs can be satisfied with a specific DBMS (the implementation of the DAO). Although this design pattern is applicable to most programming languages, most software with persistence needs, and most databases, it is traditionally associated with Java EE applications and with relational databases (accessed via the JDBC API because of its origin in Sun Microsystems' best practice guidelines "Core J2EE Patterns". Advantages The primary advantage of using data access objects is the rigorous separation between two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software
Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists of machine language instructions supported by an individual processor—typically a central processing unit (CPU) or a graphics processing unit (GPU). Machine language consists of groups of binary values signifying processor instructions that change the state of the computer from its preceding state. For example, an instruction may change the value stored in a particular storage location in the computer—an effect that is not directly observable to the user. An instruction may also invoke one of many input or output operations, for example displaying some text on a computer screen; causing state changes which should be visible to the user. The processor executes the instructions in the order they are provided, unless it is instructed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TopLink
Oracle TopLink is a mapping and persistence framework for Java developers. TopLink is produced by Oracle and is a part of Oracle's OracleAS, WebLogic, and OC4J servers. It is an object-persistence and object-transformation framework. TopLink provides development tools and run-time functionalities that ease the development process and help increase functionality. Persistent object-oriented data is stored in relational databases which helps build high-performance applications. Storing data in either XML (Extensible Markup Language) or relational databases is made possible by transforming it from object-oriented data. A rich user-interface is possible on TopLink with the help of TopLink Mapping Workbench. This Mapping Workbench makes it possible to carry out the following with ease. * Graphical mapping of an object model to data model. * Generation of data model from its object model and vice versa. * Auto-mapping of any existing data models and object models. Oracle's JDeveloper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Access Layer
A data access layer (DAL) in computer software is a layer of a computer program which provides simplified access to data stored in persistent storage of some kind, such as an entity-relational database. This acronym is prevalently used in Microsoft environments. For example, the DAL might return a reference to an object (in terms of object-oriented programming) complete with its attributes instead of a row of fields from a database table. This allows the client (or user) modules to be created with a higher level of abstraction. This kind of model could be implemented by creating a class of data access methods that directly reference a corresponding set of database stored procedures. Another implementation could potentially retrieve or write records to or from a file system. The DAL hides this complexity of the underlying data store from the external world. For example, instead of using commands such as ''insert'', ''delete'', and ''update'' to access a specific table in a databas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Create, Read, Update And Delete
In computer programming, create, read, update, and delete (CRUD) are the four basic operations of persistent storage. CRUD is also sometimes used to describe user interface conventions that facilitate viewing, searching, and changing information using computer-based forms and reports. The term was likely first popularized by James Martin in his 1983 book ''Managing the Data-base environment''. Conceptual Data can be put in a ''location/area'' of a storage mechanism. * The fundamental feature of a storage location is that its ''content'' is both ''readable'' and ''updatable''. * Before a storage location can be read or updated it needs to be ''created''; that is allocated and initialized with content. * At some later point, the storage location may need to be ''destructed''; that is finalized and deallocated. Together these four operations make up the basic operations of storage management known as CRUD: ''Create'', ''Read'', ''Update'' and ''Delete''. Databases The acro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perl
Perl is a family of two high-level, general-purpose, interpreted, dynamic programming languages. "Perl" refers to Perl 5, but from 2000 to 2019 it also referred to its redesigned "sister language", Perl 6, before the latter's name was officially changed to Raku in October 2019. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language". Perl was developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions. Raku, which began as a redesign of Perl 5 in 2000, eventually evolved into a separate language. Both languages continue to be developed independently by different development teams and liberally borrow ideas from each other. The Perl languages borrow features from other programming languages including C, sh, AWK, and sed; They provide text processing facilities without the arbitrary data-le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entity Framework
Entity Framework (EF) is an open source object–relational mapping (ORM) framework for ADO.NET. It was originally shipped as an integral part of .NET Framework, however starting with Entity Framework version 6.0 it has been delivered separately from the .NET Framework. Entity Framework 6.4 was the latest release of the classic framework. Although Entity Framework 6 is still supported, it is no longer being developed and will only receive fixes for security issues. A new framework known as Entity Framework Core (EF Core) was introduced in 2016 with similar but not complete feature parity. Version numbering of this framework restarted from 1.0 and the latest version of EF Core is 7.0. Overview The Entity Framework is a set of technologies in ADO.NET that supports the development of data-oriented software applications. Architects and developers of data-oriented applications have typically struggled with the need to achieve two very different objectives. They must model the enti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ODB (C++)
ODB may refer to: People * Ol' Dirty Bastard (1968–2004), American rapper and founding member of the Wu-Tang Clan * ODB (wrestler) (born 1978), Stage name of American professional wrestler Jessica Kresa * Original David Baker (born 1972), a moniker of American poker player David Baker Computers and technology * .odb file extension for OpenDocument format databases * Object database * ODB++, a CAD-to-CAM data exchange format used in the design and manufacture of electronic devices Publications * ''Our Daily Bread (devotional)'', Christian devotional booklets produced by Our Daily Bread Ministries * ''Oxford Dictionary of Byzantium The ''Oxford Dictionary of Byzantium'' (ODB) is a three-volume historical dictionary published by the English Oxford University Press. With more than 5,000 entries, it contains comprehensive information in English on topics relating to the Byzant ...'', a three volume historical dictionary published by Oxford University Press Other uses * ODB, the I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstraction Inversion
In computer programming, abstraction inversion is an anti-pattern arising when users of a construct need functions implemented within it but not exposed by its interface. The result is that the users re-implement the required functions in terms of the interface, which in its turn uses the internal implementation of the same functions. This may result in implementing lower-level features in terms of higher-level ones, thus the term 'abstraction inversion'. Possible ill-effects are: * The user of such a re-implemented function may seriously underestimate its running-costs. * The user of the construct is forced to obscure their implementation with complex mechanical details. * Many users attempt to solve the same problem, increasing the risk of error. Examples Alleged examples from professional programming circles include: * In Ada, choice of the ''rendezvous'' construct as a synchronisation primitive forced programmers to implement simpler constructs such as semaphores on the mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duplicate Code
In computer programming, duplicate code is a sequence of source code that occurs more than once, either within a program or across different programs owned or maintained by the same entity. Duplicate code is generally considered undesirable for a number of reasons. A minimum requirement is usually applied to the quantity of code that must appear in a sequence for it to be considered duplicate rather than coincidentally similar. Sequences of duplicate code are sometimes known as code clones or just clones, the automated process of finding duplications in source code is called clone detection. Two code sequences may be duplicates of each other without being character-for-character identical, for example by being character-for-character identical only when white space characters and comments are ignored, or by being token-for-token identical, or token-for-token identical with occasional variation. Even code sequences that are only functionally identical may be considered duplicate cod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaky Abstraction
In software development, a leaky abstraction is an abstraction that leaks details that it is supposed to abstract away. As coined by Joel Spolsky, the Law of Leaky Abstractions states: This statement highlights a particularly problematic cause of software defects: the reliance of the software developer on an abstraction's infallibility. Spolsky's article gives examples of an abstraction that works most of the time, but where a detail of the underlying complexity cannot be ignored, thus leaking complexity out of the abstraction back into the software that uses the abstraction. History The term "leaky abstraction" was popularized in 2002 by Joel Spolsky. An earlier paper by Kiczales describes some of the issues with imperfect abstractions and presents a potential solution to the problem by allowing for the customization of the abstraction itself. Effect on software development As systems become more complex, software developers must rely upon more abstractions. Each abstraction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apache OpenJPA
OpenJPA is an open source implementation of the Java Persistence API specification. It is an object-relational mapping (ORM) solution for the Java language, which simplifies storing objects in databases. It is open-source software distributed under the Apache License 2.0. History Kodo, a Java Data Objects implementation, was originally developed by SolarMetric, Inc in 2001. BEA Systems acquired SolarMetric in 2005, where Kodo was expanded to be an implementation of both the JDO (JSR 12) and JPA (JSR 220) specifications. In 2006, BEA donated a large part of the Kodo source code to the Apache Software Foundation under the name OpenJPA. The donated source code will be the core persistence engine of BEA Weblogic Server, IBM WebSphere, and the Geronimo Application Server. In May 2007, OpenJPA graduated from the incubator to a top-level project and also passed Sun's Technology Compatibility Kit compliant with the Java Persistence API. See also * Persistence * EclipseLink ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBATIS
iBATIS is a persistence framework which automates the mapping between SQL databases and objects in Java, .NET, and Ruby on Rails. In Java, the objects are POJOs ( Plain Old Java Objects). The mappings are decoupled from the application logic by packaging the SQL statements in XML configuration files. The result is a significant reduction in the amount of code that a developer needs to access a relational database using lower level APIs like JDBC and ODBC. Other persistence frameworks such as Hibernate allow the creation of an object model (in Java, say) by the user, and create and maintain the relational database automatically. iBATIS takes the reverse approach: the developer starts with a SQL database and iBATIS automates the creation of the Java objects. Both approaches have advantages, and iBATIS is a good choice when the developer does not have full control over the SQL database schema. For example, an application may need to access an existing SQL database used by ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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