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Relational database

Relational database
In the relational model, each table schema must identify a column or group of columns, called the primary key, to uniquely identify each row. A relationship can then be established between each row in the table and a row in another table by creating a foreign key, a column or group of columns in one table that points to the primary key of another table. The relational model offers various levels of refinement of table organization and reorganization called database normalization. (See Normalization below.) The database management system (DBMS) of a relational database is called an RDBMS, and is the software of a relational database. In relational databases, each data item has a row of attributes, so the database displays a fundamentally tabular organization. Relational databases are both created and queried by DataBase Management Systems (DBMSs). Terminology[edit] Relational database terminology. Relations or Tables[edit] Tuples by definition are unique. Base and derived relations[edit]

The Computer Revolution/Databases/Database Models Hierarchical Databases[edit] Hierarchical databases are the oldest database models. Unlike other models, they do not have a well documented history. The hierarchical database was the first one developed and therefore was commonly used in the first mainframe database management systems.They were developed out of the 1950's and 60's Information Management Systems. Many banks and insurance companies, as well as government departments and hospitals ( for inventory and accounting systems) still use them today. The hierarchical database stores data in a series of records. As an example, we could have a tree representing a university department, with subtrees representing staff members, students, courses, and facilities. A hierarchical database has a very structured form, as it allows no links between layers in different branches of the tree. Advantages of the Database[edit] Shortcomings of the Database[edit] Currently this type of database is not utilized to its full potential. 1. 2. 3. 4. 5.

ATC/DDD Anatomical-therapeutic-chemical Classification with Defined Daily Doses ATC-Classification with Defined Daily Doses DIMDI publishes the annually updated official version of the German Anatomical Therapeutic Chemical (ATC)-Classification with defined daily doses (DDD) since January 1st, 2004. You can download a PDF file of the official German ATC-Classification (in German) for free: ATC/DDD as PDF file for free at downloadcenter Classification You can download an Excel file of the official ATC-Classification with DDD from the WldO website (on the right side below "Downloads") for free: ATC/DDD as Excel file for free at WIdO It is pointed out that in case of probable differences only the PDF file is binding which can be downloaded from the DIMDI website via the above mentioned link. ATC-Classification In the ATC-Classification substances are divided into different groups according to the organ or organ system which they affect and their chemical, pharmacological and therapeutic properties.A defined daily dose is assigned to each active substance. Legal Background

What are relational databases?" Databases have been a staple of business computing from the very beginning of the digital era. In fact, the relational database was born in 1970 when E.F. Codd, a researcher at IBM, wrote a paper outlining the process. Since then, relational databases have grown in popularity to become the standard. Originally, databases were flat. This means that the information was stored in one long text file, called a tab delimited file. Lname, FName, Age, Salary|Smith, John, 35, $280|Doe, Jane, 28, $325|Brown, Scott, 41, $265|Howard, Shemp, 48, $359|Taylor, Tom, 22, $250 You can see that you have to search sequentially through the entire file to gather related information, such as age or salary. With a relational database, you can quickly compare information because of the arrangement of data in columns. The "relational" part of the name comes into play because of mathmatical relations. Here are some interesting links:

DIMDI - ATC/DDD Anatomical-therapeutic-chemical Classification with Defined Daily Doses ATC-Classification with Defined Daily Doses DIMDI publishes the annually updated official version of the German Anatomical Therapeutic Chemical (ATC)-Classification with defined daily doses (DDD) since January 1st, 2004. You can download a PDF file of the official German ATC-Classification (in German) for free: ATC/DDD as PDF file for free at downloadcenter Classification You can download an Excel file of the official ATC-Classification with DDD from the WldO website (on the right side below "Downloads") for free: ATC/DDD as Excel file for free at WIdO It is pointed out that in case of probable differences only the PDF file is binding which can be downloaded from the DIMDI website via the above mentioned link. ATC-Classification In the ATC-Classification substances are divided into different groups according to the organ or organ system which they affect and their chemical, pharmacological and therapeutic properties.A defined daily dose is assigned to each active substance. Legal Background

Choosing a Database Oracle, SQL Server, Microsoft Access, MySQL, DB2, Paradox. There are quite a variety of database products on the market today, making the selection of a platform for your organization's infrastructure a daunting project. Define Your Requirements Database management systems (or DBMSs) can be divided into two categories -- desktop databases and server databases. Generally speaking, desktop databases are oriented toward single-user applications and reside on standard personal computers (hence the term desktop). Server databases contain mechanisms to ensure the reliability and consistency of data and are geared toward multi-user applications. It's important to do a careful needs analysis before you dive in and commit to a database solution. The needs analysis process will be specific to your organization but, at a minimum, should answer the following questions: Who will be using the database and what tasks will they perform? Desktop Databases Server Databases Flexibility.

DIMDI - ICD-10-GM Version 2016 Übersicht über die Kapitel Kapitel IBestimmte infektiöse und parasitäre Krankheiten(A00-B99) Dieses Kapitel gliedert sich in folgende Gruppen: Kapitel IINeubildungen(C00-D48) Kapitel VIKrankheiten des Nervensystems(G00-G99) G00-G09Entzündliche Krankheiten des ZentralnervensystemsG10-G14Systematrophien, die vorwiegend das Zentralnervensystem betreffenG20-G26Extrapyramidale Krankheiten und BewegungsstörungenG30-G32Sonstige degenerative Krankheiten des NervensystemsG35-G37Demyelinisierende Krankheiten des ZentralnervensystemsG40-G47Episodische und paroxysmale Krankheiten des NervensystemsG50-G59Krankheiten von Nerven, Nervenwurzeln und NervenplexusG60-G64Polyneuropathien und sonstige Krankheiten des peripheren NervensystemsG70-G73Krankheiten im Bereich der neuromuskulären Synapse und des MuskelsG80-G83Zerebrale Lähmung und sonstige LähmungssyndromeG90-G99Sonstige Krankheiten des Nervensystems Kapitel XVSchwangerschaft, Geburt und Wochenbett(O00-O99)

Home The Department for Education's register of educational establishments in England and Wales. Using the search box below select school type and location to quickly find establishments in your local area or use the advanced search page for further search criteria including establishments that are closed or planned to open in the future. From this page you are able to perform a simple search of all open establishments in England and Wales. If you leave a field blank, the default will include all establishments. The 'Show me' drop down list allows you to select the type of establishment you wish to see in your search results. You have the ability to search by location, and can set a radius of inclusion. When searching by establishment name, often it is best to search for a single word in a name. Church of England is generally referred to as CofE in EduBase. For more advanced searches, or to find closed schools, please use the Advanced search page Contacting EduBase Disclaimer

National drug databases - EU :: INFOlinks Explanatory note: ATC = database allows search according to ATC classification. Rx/OTC = database allows search according to Rx/OTC. Germany - Fachinformation or Summary of Product Characteristics and Package Leaflet, Public Assessment Reports (for medicines registered via NP or where BfArM is RMS). Ten Common Database Design Mistakes No list of mistakes is ever going to be exhaustive. People (myself included) do a lot of really stupid things, at times, in the name of “getting it done.” This list simply reflects the database design mistakes that are currently on my mind, or in some cases, constantly on my mind. I have done this topic two times before. Before I start with the list, let me be honest for a minute. So, the list: Poor design/planning Ignoring normalization Poor naming standards Lack of documentation One table to hold all domain values Using identity/guid columns as your only key Not using SQL facilities to protect data integrity Not using stored procedures to access data Trying to build generic objects Lack of testing Poor design/planning “If you don’t know where you are going, any road will take you there” – George Harrison Prophetic words for all parts of life and a description of the type of issues that plague many projects these days. Ignoring Normalization Are there always 12 payments? Maintainability

Rote Liste What is database Main » TERM » D » By Vangie Beal (1) Often abbreviated DB, a database is basically a collection of information organized in such a way that a computer program can quickly select desired pieces of data. You can think of a database as an electronic filing system. Traditional databases are organized by fields, records, and files. An alternative concept in database design is known as Hypertext. To access information from a database, you need a database management system (DBMS). (2) Increasingly, the term database is used as shorthand for database management system. Accueil WHOCC - ATC/DDD Index A searchable version of the complete ATC index with DDDs is available below. The search options enable you to find ATC codes and DDDs for substance name and/or ATC levels. In your search result you may choose to show or hide the text from the Guidelines for ATC classification and DDD assignment linked to the ATC level. ATC code All ATC levels are searchable.A search will result in showing the exact substance/level and all ATC levels above (up to 1st ATC level). Name "Name" is defined as the name of the substance (normally the INN name) or the name of the ATC level. The DDDs, which will be reviewed in 2016 (3 year revision), are listed here and in the annex I in the printed ATC Index. To express the DDD several abbreviations are used for units and routes of administration. Units Route of administration (Adm.R)

Relational Database Management System (RDBMS): A database management system that organizes data in defined tables.

Found in: Hurwitz, J., Nugent, A., Halper, F. & Kaufman, M. (2013) Big Data For Dummies. Hoboken, New Jersey, United States of America: For Dummies. ISBN: 9781118504222. by raviii Jan 1

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