Definition:Data validation guarantees to your application that every data value is correct and accurate. You can design data validation into your application with several differing approaches: user interface code, application code, or database constraints.
Example: Simple field and lookup validation is sometimes not enough. Consider a health care claim which has a billed amount of $123.57, but the allowable amount may depend on a year-to-date rolling accumulation that is capped at $1500 (not to exceed the lifetime policy maximum of $100,000). In this situation, data validation extends beyond the immediate data entry screen to one of careful evaluation of how to pay this claim based on the policy limits and both year-to-date and lifetime accruals. This kind of complex multifile data validation is often best handled with procedure-based business rules.
http://msdn.microsoft.com/en-us/library/aa291820(VS.71).aspx
Picture:
http://blogoscoped.com/files/spreadsheet-data-validation.png
Saturday, November 20, 2010
Specialized Databases
Definition: Specialized databases are indexes that can be searched, much like the search engines.
http://www.webliminal.com/search/search-web07.html
Example:http://www.britannica.com/
Picture:
http://www.databasezone.com/images/fits_facility_site.gif
http://www.webliminal.com/search/search-web07.html
Example:http://www.britannica.com/
Picture:
http://www.databasezone.com/images/fits_facility_site.gif
database management system
Definition: A program that sorts, links, and otherwise organizes and manages data in a database. DBMS may also assist in the analysis of data and the preparation of reports.
http://www.amersol.edu.pe/hs/technology/itgs/GlossaryofTerms.asp#D
Example: Some of the more popular relational database management systems include:
http://www.amersol.edu.pe/hs/technology/itgs/GlossaryofTerms.asp#D
Example: Some of the more popular relational database management systems include:
- Microsoft Access
- Filemaker
- Microsoft SQL Server
- MySQL
- Oracle
http://www.quackit.com/database/tutorial/database_management_systems.cfm
Picture:
http://www.quackit.com/pix/database/tutorial/relational_databases_1.gif
Flat-file database, relational database, normalization
Flat-file database
Definition:A flat file database is a database that stores data in a plain text file. Each line of the text file holds one record, with fields separated by delimiters, such as commas or tabs. While it uses a simple structure, a flat file database cannot contain multiple tables like a relational database can. Fortunately, most database programs such as Microsoft Access and FileMaker Pro can import flat file databases and use them in a larger relational database.
http://www.techterms.com/definition/flatfile
Example + Picture:
http://i.msdn.microsoft.com/aa905447.Flat_DB(en-us,MSDN.10).gif
Relational Database:
Definition:A relational database is a collection of data items organized as a set of formally-described tables from which data can be accessed or reassembled in many different ways without having to reorganize the database tables. The relational database was invented by E. F. Codd at IBM in 1970.
http://searchsqlserver.techtarget.com/definition/relational-database
Example + Picture:
http://library2.usask.ca/access98/ppoint/cervone/html/sld008.htm
Normalization:
Definition: In relational database design, the process of organizing data to minimize redundancy. Normalization usually involves dividing a database into two or more tables and defining relationships between the tables. The objective is to isolate data so that additions, deletions, and modifications of a field can be made in just one table and then propagated through the rest of the database via the defined relationships.
http://www.webopedia.com/TERM/N/normalization.html
Example and picture:
http://www.mahipalreddy.com/images/Normalization.gif
Definition:A flat file database is a database that stores data in a plain text file. Each line of the text file holds one record, with fields separated by delimiters, such as commas or tabs. While it uses a simple structure, a flat file database cannot contain multiple tables like a relational database can. Fortunately, most database programs such as Microsoft Access and FileMaker Pro can import flat file databases and use them in a larger relational database.
http://www.techterms.com/definition/flatfile
Example + Picture:
http://i.msdn.microsoft.com/aa905447.Flat_DB(en-us,MSDN.10).gif
Relational Database:
Definition:A relational database is a collection of data items organized as a set of formally-described tables from which data can be accessed or reassembled in many different ways without having to reorganize the database tables. The relational database was invented by E. F. Codd at IBM in 1970.
http://searchsqlserver.techtarget.com/definition/relational-database
Example + Picture:
http://library2.usask.ca/access98/ppoint/cervone/html/sld008.htm
Normalization:
Definition: In relational database design, the process of organizing data to minimize redundancy. Normalization usually involves dividing a database into two or more tables and defining relationships between the tables. The objective is to isolate data so that additions, deletions, and modifications of a field can be made in just one table and then propagated through the rest of the database via the defined relationships.
http://www.webopedia.com/TERM/N/normalization.html
Example and picture:
http://www.mahipalreddy.com/images/Normalization.gif
Friday, November 19, 2010
Record
Definition:A single entry for an entity in a database and may be composed of more than one data field (item of data or data element).
http://www.amersol.edu.pe/hs/technology/itgs/GlossaryofTerms.asp#R
Example:The following program sorts the personnel files shown for the last example. They are sorted by last name. The output records are altered before they are output.
http://www.amersol.edu.pe/hs/technology/itgs/GlossaryofTerms.asp#R
Example:The following program sorts the personnel files shown for the last example. They are sorted by last name. The output records are altered before they are output.
Example D-4 SORTREC_OUTPUT Program
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http://docs.hp.com/en/32650-90080/apds04.html
Picture:
http://www.ucancode.net/database-loading.gif
Thursday, November 11, 2010
Field, data types, key field/primary key, secondary key
Field:
Definition:An {ordered set} of {fields}, usually stored contiguously. The term is used with similar meaning in several different contexts. In a file, a "record" probably has some fixed length, in contrast to a "line" which may have any length and is terminated by some {End Of Line} sequence). A {database} record is also called a "row". In a {spreadsheet} it is always called a "row". Some programming languages use the term to mean a type composed of fields of several other types ({C} calls this a "{struct}"). In all these cases, a record represents an entity with certain field values. Fields may be of a fixed width ({bit}s or {characters}) or they may be separated by a {delimiter} character, often {comma} ({CSV}) or {HT} ({TSV}). In a database the list of values of a given field from all records is called a column. (2002-03-22).
http://www.learnthat.com/define/view.asp?id=6799
Example:, a single VSAM file stores both employee and address records. The correct record interpretation is managed by associating the value of a record type field with a record layout. The following COBOL definition shows how a REDEFINES clause specifies an alternate record type for ADDRESS-INFORMATION. If RECORD-TYPE = "A" Classic Data Architect uses the layout for address data.
Definition:An {ordered set} of {fields}, usually stored contiguously. The term is used with similar meaning in several different contexts. In a file, a "record" probably has some fixed length, in contrast to a "line" which may have any length and is terminated by some {End Of Line} sequence). A {database} record is also called a "row". In a {spreadsheet} it is always called a "row". Some programming languages use the term to mean a type composed of fields of several other types ({C} calls this a "{struct}"). In all these cases, a record represents an entity with certain field values. Fields may be of a fixed width ({bit}s or {characters}) or they may be separated by a {delimiter} character, often {comma} ({CSV}) or {HT} ({TSV}). In a database the list of values of a given field from all records is called a column. (2002-03-22).
http://www.learnthat.com/define/view.asp?id=6799
Example:, a single VSAM file stores both employee and address records. The correct record interpretation is managed by associating the value of a record type field with a record layout. The following COBOL definition shows how a REDEFINES clause specifies an alternate record type for ADDRESS-INFORMATION. If RECORD-TYPE = "A" Classic Data Architect uses the layout for address data.
01 EMPLOYEE-ADDRESS-RECORD. 05 EMP-ID PIC X(6). 05 RECORD-TYPE PIC X. 88 RECORD-IS-EMPLOYEE VALUE 'E'. 88 RECORD-IS-ADDRESS VALUE 'A'. 05 EMPLOYEE-INFORMATION. 10 LAST-NAME PIC X(20). 10 FIRST-NAME PIC X(20). 10 DATE-OF-BIRTH PIC 9(8). 10 MONTHLY-SALARY PIC S9(5)V99 COMP-3. 10 FILLER PIC X(48). 05 ADDRESS-INFORMATION REDEFINES EMPLOYEE-INFORMATION. 10 ADDRESS-LINE-1 PIC X(30). 10 ADDRESS-LINE-2 PIC X(30). 10 ADDRESS-CITY PIC X(20). 10 ADDRESS-STATE PIC XX. 10 ADDRESS-ZIP PIC 9(5).
Picture:
http://freepages.genealogy.rootsweb.ancestry.com/~donegalstrongs/ire_db.gif
Data Types:
Definition: The description of the kinds of data stored, passed and used.
http://www.ois.com/Products/glossary-of-terms.html#d
Data Types:
Definition: The description of the kinds of data stored, passed and used.
http://www.ois.com/Products/glossary-of-terms.html#d
Example and Picture:
Examine the differences between qualitative and quantitative data.
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Table
Definition:
a set of data arranged in rows and columns;
In relational databases and flat file databases, a table is a set of data elements (values) that is organized using a model of vertical columns (which are identified by their name) and horizontal rows. A table has a specified number of columns, but can have any number of rows.
http://www.google.com.lb/search?hl=en&source=hp&biw=1436&bih=687&q=define%3A+table&rlz=1R2ADFA_enLB395&aq=f&aqi=g10&aql=&oq=&gs_rfai=
Example and picture:
http://www.cisco.com/en/US/i/100001-200000/110001-120000/119001-120000/119668.jpg
Example and picture:
http://www.cisco.com/en/US/i/100001-200000/110001-120000/119001-120000/119668.jpg
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