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Databases (Definitions (Entity: A subject, which has a lot of attributes,…
Databases
Definitions
Entity: A subject, which has a lot of attributes, this could be a person, game
Attributes: Data attached to a entity, for example if the entity was a student the attributes of it may be name, address , grade
Record: One row in a table in a database, this normally contains all the information about a single primary key
Primary Key: An attribute of a databases which is a unique identifier and can link several different tables together
Secondary key: It is a field which has been indexed for faster searchers, there may be more than one per table of information. This may also be known as a foreign key
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One-to-many relationship: This is were one row may relate to more than one other field in a relational database
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Relational Database: One that contains two or more tables of data, connected by links called relationships
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Database security
They are able to keep databases secure by having restrictions , backups in case of theft, reviewing old systems and finding different weaknesses and capacity testing and limits to stop it from crashing or stop working correctly
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Database security covers security on all aspects and components of databases. For example: Data stored in a database, Database servers, Database management system(DBMS)
parts of a database
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Database client: A data-base server and IOS client on a different machine/computer communicate with each other
Logic operators ( Not, AND, OR
.NOT. : logical not
.AND. : logical and
.OR. : logical or
.EQV. : logical equivalence
.NEQV. : logical not equivalence
= Equal
Greater than >
< Less than
= Greater than or equal
<= Less than or equal
<> Not equal
Database management systems: A Database management system(DBMS) is system software for creating and management databases, The DMBS provides uses and programmers with a systematic way to create, retrieve, update and manage data