Database Dictionary

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database: A arsenal ofrelated information stored in a structured format. Database is sometimesused interchangeably through the hatchet table. Technically, they�redifferent: A table is a single store of associated information; a database canconsist the one or an ext tables of details that are connected in someway. Because that instance, you can track all the information around the student in aschool in a student table. If girlfriend then produced separate tables containingdetails around teachers, classes and also classrooms, girlfriend could incorporate all fourtables right into a timetabling database. Together a multi-table database is called a relationaldatabase.

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data entry: The procedure of acquiring information right into adatabase, generally done by people typing that in by means of data-entry formsdesigned to leveling the process.

dbms: Database management system. A regimen which letsyou regulate informationin databases. Lotus Approach, Microsoft accessibility and FileMakerPro, for example, are all DBMSs, although the hatchet is frequently shortened to�database�. So, the exact same term is offered to apply to the regime you usage to organizeyour data and also the yes, really data framework you produce with the program.

field: Fields define a solitary aspect of each member the a table. A student record, because that instance, mightcontain a last surname field, a first name field, a date of birth field and so on.All records have exactly the very same structure, for this reason they contain the very same fields.The worths in each field vary from document to record, the course. In somedatabase systems, you�ll uncover fields described as attributes.

flat file: A database that consists of asingle table. Lightweight database programs such together the databasecomponent in Microsoft Works space sometimes referred to as �flat-file managers� (or listmanagers) due to the fact that they have the right to only take care of single-table databases. More powerfulprograms, such as FileMaker Pro, Access, Approach and Paradox, deserve to handlemulti-table databases, and are called relational database managers, or RDBMSs.

foreign key: A crucial used in one table to represent the value of a primary key in a associated table.While primary tricks must contain distinct values, international keys may have duplicates.For instance, if we usage student ID together the primary crucial in a student table (eachstudent has actually a distinctive ID), we can use college student ID as a foreign an essential in a StudentCoursetable: together each student may do more than one course, the student ID field in theStudentCourse table (often shortened to StudentCourse.student ID) will certainly holdduplicate values.

index: A an overview table which allows you easily look up thecontents of any kind of record in a table. Think of exactly how you usean table of contents to a book: as a fast jumping off allude to finding full informationabout a subject. A database index works in a comparable way. Friend can produce anindex on any field in a table. Say, because that example, girlfriend havea customer table which contains customer numbers, names, addresses and otherdetails. You deserve to make indexes based on any kind of information, such as the customers�customer number, last name + first name (a composite index based on much more thanone field), or postal code. Then, as soon as you�re searching for a particularcustomer or team of customers, you deserve to use the table of contents to rate up the search.This increase in performance may not be noticeable in a table containing ahundred records; in a database that thousands of records it will certainly be a blessing.

key field: You deserve to sort and also quickly retrieve info from a database by picking one or more fields to act as keys.For instance, in a student table you can use a combination of the critical nameand first name fields (or perhaps last name, an initial name and birth dates toensure you identify each college student uniquely) as a vital field. The database programwill create an index containing just the an essential field contents.Using the index, friend can quickly find any record by typing in thestudent�s name. The database will find the correct entry in the table of contents andthen screen the full record.

Key areas arealso supplied in relational databases to maintain thestructural integrity of your tables, helping you come avoid problems such asduplicate records and also conflicting worths in areas (see primary key and also foreign key).

normalization: The procedure ofstructuring data to minimize duplication and also inconsistencies. The processusually involves breaking down a solitary table into two or moretables and also defining relationships in between those tables. Normalization isusually excellent in stages, through each phase applying much more rigorous rule to thetypes of details that can be stored in a table. While full adherence to normalizationprinciples increases the effectiveness of a specific database, the process canbecome therefore esoteric that you need a experienced to create and understand thetable design. Most people, when producing a database, don�t have to go beyondthe third level the normalization, called third normal form.

primarykey: A field that unique identifies a record in a table. In astudents table, for instance, a vital built indigenous last name + an initial name might notgive you a unique identifier (two or an ext Jane walk in the school, forexample). Come uniquely determine each student, girlfriend might include a special Student IDfield come be provided as the main key.

query: A check out of your data showing details from one or moretables. For instance, you could query the student database asking "Showme the first and critical names the the students that take both history and geographyand have Alice Hernandez as their advisor" such a query displaysinformation indigenous the college student table (firstname, lastname), brickandmortarphilly.com table(course description) and also Advisor table (advisor name), using the tricks (studentID, food ID, advisor ID) come find matching information.

rdbms: Relational database management system. A program which lets youmanage structured info stored in tables and which have the right to handle databases consist of of many tables.

record: A record includes all the information around a solitary �member� that atable. In a student table, every student�s details (name, dateof birth, call details, and also so on) will be consisted of in its own record.Records are additionally known as tuples in technological relational database parlance.

relational database: A database consists of much more than one table. In a multi-tabledatabase, you not only need to specify the structure of each table, you alsoneed to define the associations between each table in bespeak to attach thosetables correctly.

report: A type designed come print details from a database(either on the screen, to a paper or directly to the printer).

SQL: Structured questions Language (pronounced sequel inthe US; ess-queue-ell elsewhere). A computer language designed come organizeand leveling the process of obtaining information out of a database in a usableform, and likewise used come reorganize data in ~ databases. SQL is most frequently usedon larger databases on minicomputers, mainframes and also corporate servers.

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table: A solitary store of related information. A table consists ofrecords, and also each document is comprised of a variety of fields. Simply to entirely confuse things, tables space sometimes dubbed relations.You deserve to think of the phone publication as a table: It contains a document for eachtelephone subscriber, and also each subscriber�s details are contained in threefields � name, resolve and telephone.