Relational database

relational database management systemRDBMSrelational databases
DRDA enables network connected relational databases to cooperate to fulfill SQL requests. The messages, protocols, and structural components of DRDA are defined by the Distributed Data Management Architecture. According to DB-Engines, in July 2019, the most widely used systems were Oracle, MySQL (free software), Microsoft SQL Server, PostgreSQL (free software), IBM DB2, Microsoft Access, SQLite (free software), and MariaDB (free software).

Oracle Corporation

OracleOracle Technology NetworkOracle Corp.
Oracle Corporation's main competitors in the database arena remain IBM DB2 and Microsoft SQL Server, and to a lesser extent Sybase and Teradata, with open source databases such as PostgreSQL and MySQL also having a significant share of the market. EnterpriseDB, based on PostgreSQL, has made inroads by proclaiming that its product delivers Oracle compatibility features at a much lower price-point. In the software-applications market, Oracle Corporation primarily competes against SAP. On March 22, 2007 Oracle sued SAP, accusing them of fraud and unfair competition.

IBM Db2 Family

DB2IBM DB2pureQuery
DB2 9.7 added data compression for database indexes, temporary tables, and large objects. DB2 9.7 also supported native XML data in hash partitioning (database partitioning), range partitioning (table partitioning), and multi-dimensional clustering. These native XML features allows users to directly work with XML in data warehouse environments. DB2 9.7 also added several features that make it easier for Oracle Database users to work with DB2. These include support for the most commonly used SQL syntax, PL/SQL syntax, scripting syntax, and data types from Oracle Database.

Comparison of relational database management systems

Note (1):
Comparison of different SQL implementations against SQL standards. Includes Oracle, DB2, Microsoft SQL Server, MySQL and PostgreSQL. (8 June 2007). The SQL92 standard. DMBS comparison by SQL Workbench.

Database abstraction layer

DALdatabase abstractiondatabase abstraction library
These problems magnify significantly with database size, scale, and complexity. * Object-relational mapping

Microsoft Access

AccessMS AccessAccess 2000
ODBC-compliant data containers, including:. Microsoft SQL Server. Oracle. MySQL. PostgreSQL. IBM Lotus Notes. AS 400 DB2. 1) Data Access Objects (DAO) (32-bit only), which is included in Access and Windows and evolved to ACE in Microsoft Access 2007 for the ACCDE database format. 2) ActiveX Data Objects ActiveX Data Objects (ADO) (both 32-bit and 64-bit versions). Comparison of relational database management systems. Form (web). MDB Tools. Kexi. Access Blog. Microsoft Access Version Releases, Service Packs, Hotfixes, and Updates History.


The first installment of SQL:1999 had five parts: Three more parts, also considered part of SQL:1999 were published subsequently: The SQL:1999 standard calls for a Boolean type, but many commercial SQL servers (Oracle Database, IBM DB2) do not support it as a column type, variable type or allow it in the results set. Microsoft SQL Server is one of the few database systems that properly supports BOOLEAN values using its "BIT" data type. Every 1–8 bit fields occupies one full byte of space on disk. MySQL interprets "BOOLEAN" as a synonym for TINYINT (8-bit signed integer).

Microsoft Visual Studio

Visual StudioVisual Studio 2005Visual Studio 2008
Data Explorer: Data Explorer is used to manage databases on Microsoft SQL Server instances. It allows creation and alteration of database tables (either by issuing T-SQL commands or by using the Data designer). It can also be used to create queries and stored procedures, with the latter in either T-SQL or in managed code via SQL CLR. Debugging and IntelliSense support is available as well. Server Explorer: The Server Explorer tool is used to manage database connections on an accessible computer. It is also used to browse running Windows Services, performance counters, Windows Event Log and message queues and use them as a datasource.

Java Database Connectivity

JDBCJava Data Base ConnectivityJava Database Connectivity (JDBC)
SchemaCrawler is an open source API that leverages JDBC, and makes database metadata available as plain old Java objects (POJOs). GNU Data Access (GDA). JDBCFacade. Open Database Connectivity (ODBC). This documentation has examples where the JDBC resources are not closed appropriately (swallowing primary exceptions and being able to cause NullPointerExceptions) and has code prone to SQL injection. API Javadoc documentation. API Javadoc documentation. O/R Broker Scala JDBC framework. SqlTool Open source, command-line, generic JDBC client utility. Works with any JDBC-supporting database. JDBC URL Strings and related information of All Databases.

Comparison of object-relational database management systems

List of object-relational database management systems
. *, Comparison of different SQL implementations Comparison of database tools. Comparison of object database management systems. Comparison of relational database management systems. List of relational database management systems.

Application programming interface

APIAPIsapplication programming interfaces
In 2010, Oracle Corporation sued Google for having distributed a new implementation of Java embedded in the Android operating system. Google had not acquired any permission to reproduce the Java API, although permission had been given to the similar OpenJDK project. Judge William Alsup ruled in the ''Oracle v.


Scriptcase lets you create forms, queries in PHP, ranging from simple forms to forms having high level of complex elements to manipulate data from databases (MySQL, PostgreSQL, SQLite, Interbase, Firebird, Access, Oracle, MS SQLServe r, DB2, SyBase, Informix and ODBC connections). It permits development with JavaScript methods that can be used within the AJAX events and create applications with AJAX through a set of features and services with easy and fast hand coding, such as navigation between pages or sections, automatic validation of fields such as date, currency, zip code and social security number, among others.

Perl DBI

DBIdatabasesPerl's DBI
DBD implementations exist for proprietary products such as IBM DB2, Microsoft SQL Server, Oracle and for free-software databases such as SQLite, PostgreSQL, Firebird and MySQL. PHP 5 has a similar interface called PHP Data Objects (PDO). Java's Java Database Connectivity (JDBC) is also similar. * DBD drivers on MetaCPAN DBI module documentation on MetaCPAN. DBD drivers on MetaCPAN.

Database schema

schemarelational schemaschemas
The database schema of a database is its structure described in a formal language supported by the database management system (DBMS). The term "schema" refers to the organization of data as a blueprint of how the database is constructed (divided into database tables in the case of relational databases). The formal definition of a database schema is a set of formulas (sentences) called integrity constraints imposed on a database. These integrity constraints ensure compatibility between parts of the schema. All constraints are expressible in the same language. A database can be considered a structure in realization of the database language.

Database trigger

triggerstriggerprocedural triggers
MySQL DB Create Triggers. DB2 CREATE TRIGGER statement. Oracle CREATE TRIGGER. PostgreSQL CREATE TRIGGER. Oracle Mutating Table Problems with DELETE CASCADE. SQLite Query Language: CREATE TRIGGER. Oracle's Documentation on Triggers.

View (SQL)

viewviewsdatabase view
Views can act as aggregated tables, where the database engine aggregates data (sum, average, etc.) and presents the calculated results as part of the data. Views can hide the complexity of data. For example, a view could appear as Sales2000 or Sales2001, transparently partitioning the actual underlying table. Views take very little space to store; the database contains only the definition of a view, not a copy of all the data that it presents. Depending on the SQL engine used, views can provide extra security. Views in Microsoft SQL Server. Views in MySQL. Views in PostgreSQL. Views in SQLite. Views in Oracle 11.2. Views in CouchDB. Views in NuoDB.

C (programming language)

CC programming languageC language
C has operators for: C uses the operator (used in mathematics to express equality) to indicate assignment, following the precedent of Fortran and PL/I, but unlike ALGOL and its derivatives. C uses the operator to test for equality. The similarity between these two operators (assignment and equality) may result in the accidental use of one in place of the other, and in many cases, the mistake does not produce an error message (although some compilers produce warnings). For example, the conditional expression might mistakenly be written as, which will be evaluated as true if is not zero after the assignment. The C operator precedence is not always intuitive.

Comparison of database tools

database toolmulti-database query, design, and database comparison tool
Some - can only reverse engineer the entire database at once and drops any user modifications to the diagram (can't "refresh" the diagram to match the database). Forward engineering - the ability to update the database schema with changes made to its entities and relationships via the ER diagram visual designer. Yes - can update user-selected entities. Some - can only update the entire database at once. Comparison of data modeling tools. Comparison of object database management systems. Comparison of object-relational database management systems. Comparison of relational database management systems. List of relational database management systems. SQL programming tool.

Ingres (database)

IngresIngres CorporationIngres Database
Ingres spawned a number of commercial database applications, including Sybase, Microsoft SQL Server, NonStop SQL and a number of others. Postgres (Post Ingres), a project which started in the mid-1980s, later evolved into PostgreSQL. It is ACID compatible and is fully transactional (including all DDL statements) and is part of the Lisog open-source stack initiative. In 1973 when the System R project was getting started at IBM, the research team released a series of papers describing the system they were building.


C++ programming languageC++98C with Classes
C++ has also been found useful in many other contexts, with key strengths being software infrastructure and resource-constrained applications, including desktop applications, servers (e.g. e-commerce, Web search, or SQL servers), and performance-critical applications (e.g. telephone switches or space probes). C++ is standardized by the International Organization for Standardization (ISO), with the latest standard version ratified and published by ISO in December 2017 as ISO/IEC 14882:2017 (informally known as C++17). The C++ programming language was initially standardized in 1998 as ISO/IEC 14882:1998, which was then amended by the C++03, C++11 and C++14 standards.

Embedded SQL

The SQL standards committee defined the embedded SQL standard in two steps: a formalism called Module Language was defined, then the embedded SQL standard was derived from Module Language. The SQL standard defines embedding of SQL as embedded SQL and the language in which SQL queries are embedded is referred to as the host language. A popular host language is C. Host language C and embedded SQL, for example, is called Pro*C in Oracle and Sybase database management systems and ECPG in the PostgreSQL database management system. SQL may also be embedded in languages like PHP etc.

Join (SQL)

joinjoinsInner join
Set operations (SQL). Specific to products. Sybase ASE 15 Joins. MySQL 5.7 Joins. PostgreSQL 9.3 Joins. Joins in Microsoft SQL Server. Joins in MaxDB 7.6. Joins in Oracle 12c R1. Oracle SQL Joins.

Database server

SQL Serverdatabasedatabase servers
In a master-slave model, database master servers are central and primary locations of data while database slave servers are synchronized backups of the master acting as proxies. Most database applications respond to a query language. Each database understands its query language and converts each submitted query to server-readable form and executes it to retrieve results. Examples of proprietary database applications include Oracle, DB2, Informix, and Microsoft SQL Server. Examples of free software database applications include PostgreSQL; and under the GNU General Public Licence include Ingres and MySQL. Every server uses its own query logic and structure.


Adminer (formerly known as phpMinAdmin) is a tool for managing content in MySQL databases (since version 2 also in PostgreSQL, MS SQL, SQLite and Oracle databases). Adminer is distributed under Apache license (or GPL v2) in a form of a single PHP file (around 470 KiB in size). Its author is Jakub Vrána who started to develop this tool as a light-weight alternative to phpMyAdmin, in July 2007. Adminer got some attention in 2008 when it made it to the CCA finals at SourceForge. Also, first webhosting providers started to include Adminer as MySQL managing tool into their portfolio of services. In 2012 Adminer got coverage on for the second time.


Brion VibberMediaWiki.orgtalk page
MediaWiki can use either the MySQL/MariaDB, PostgreSQL or SQLite relational database management system. There is limited support for Oracle Database and Microsoft SQL Server. A MediaWiki database contains several dozen tables, including a table that contains page titles, page ids, and other metadata; and a table to which is added a new row every time an edit is made, containing the page id, a brief textual summary of the change performed, the user name of the article editor (or its IP address the case of an unregistered user) and a timestamp. In a 4½ year period, the MediaWiki database had 170 schema versions.