Process of design database :
Analysis conditions
Comprehending and knowing data which must be kept in database, application what have to be woke up by above him, type operate for what will be used
Conceptual design data base
collected information at phase analyze conditions used to develop high level data description
This step is often conducted by using model of E-R
Its Target is to create simple picture about data which too like with idea of consumer / user
Design data base logic
Change scheme of E-R become database scheme of relational
Its target is to obtain conceptual scheme at data model of relational which is often named by logic scheme
Repair of scheme
Analysis a group of relationship in database scheme of relational to identify problems which emerge and improve it
Design database physical
This step include making of index at some tables, grouping some tables or entangle design repeat which is substantial to database scheme some part
Design application and security
All project of software entangling a DBMS have to consider application aspect which beyond database
Entity-Relationship (E-R)
Data model of Entity-Relationship (E-R) consist of a group of objects, so called with relation and entity that happened among objects
Data model of E-R divided to become three elementary concept, that is : gathering of entity, gathering of relationship, and attribute
Entity and gathering of entity set
An entity represent an individual or elementary object which deputize its something tangible of him and can be differentiated from other objects
An entity have a group of nature of and assess from some nature of the is unique able to identify the entity
Gathering of entity
A group of entity having is same type and stay in is same scope form an gathering of entity
For example, a group of one who become student at one particular college, can be defined as gathering of entity student. So that can be said that by entity show at individual an object, while gathering of entity show at clump of individual
An entity have attribute. Attribute represent the nature of or property had by entity. This attribute differentiate between entity which is one with other entity
Relationship show the existence of relation among a number of entity coming from a number of gathering of entity different
Cardinality Relationship
Cardinality represent optimum of entity, where the entity can relation with entity at gathering of entity other
Type of cardinality relationship
One to One
An entity in gathering of entity A attributed to at most one entity in B entity in gathering and entity in gathering of entity B attributed to at most one entity in gathering of entity A
One to Many
An entity in gathering of entity A attributed to more than one entity in gathering of entity B, and entity in gathering of entity B can only be attributed to at most one entity in gathering of entity A
Many to One
An entity in gathering of entity A attributed to at most one entity in gathering of entity B, and entity in gathering of entity B can be attributed to more than one entity in gathering of entity A
Many to Many
An entity in gathering of entity A can be attributed to more than one entity in gathering of entity B, and entity in gathering of entity B can be attributed to more than one entity in gathering of entity A
Key
Key represent one or alliance from some attribute able to differentiate all data line uniquely
If an attribute become key, hence there may not be any two or more data line of equal value
Type of key :
Super Key
Candidate Key
Primary Key
Diagram Entity-Relationship (Diagram E-R)
An database, can be depicted graph with an diagram of E-R
Notation of E-R :
Square of length, depicting gathering of entity
-
Elliptical, depicting attributes (functioning attribute as key highlighted)
Ramble, depicting gathering of relationship
Line, depicting attribute relation to gathering and entity of entity to gathering of relationship
-
Relationship cardinality can be depicted with many line him branch or with usage of number, 1 for relationship one, n for relationship many
Step making of Diagram E-R
Identifying and specifying entire / all gathering of entity to involve
Determining attributes of key from each gathering of entity
-
Identifying and specifying entire / all relationship gathering among gathering of entity existing along with key foreign
Determining degree of cardinality to each relationship gathering
-
Equipping gathering of entity relationship gathering and with attribute of descriptive (non key)
Process of design database :
Analysis conditions
Comprehending and knowing data which must be kept in database, application what have to be woke up by above him, type operate for what will be used
Conceptual design data base
collected information at phase analyze conditions used to develop high level data description
This step is often conducted by using model of E-R
Its Target is to create simple picture about data which too like with idea of consumer / user
Design data base logic
Change scheme of E-R become database scheme of relational
Its target is to obtain conceptual scheme at data model of relational which is often named by logic scheme
Repair of scheme
Analysis a group of relationship in database scheme of relational to identify problems which emerge and improve it
Design database physical
This step include making of index at some tables, grouping some tables or entangle design repeat which is substantial to database scheme some part
Design application and security
All project of software entangling a DBMS have to consider application aspect which beyond database
Entity-Relationship (E-R)
Data model of Entity-Relationship (E-R) consist of a group of objects, so called with relation and entity that happened among objects
Data model of E-R divided to become three elementary concept, that is : gathering of entity, gathering of relationship, and attribute
Entity and gathering of entity set
An entity represent an individual or elementary object which deputize its something tangible of him and can be differentiated from other objects
An entity have a group of nature of and assess from some nature of the is unique able to identify the entity
Gathering of entity
A group of entity having is same type and stay in is same scope form an gathering of entity
For example, a group of one who become student at one particular college, can be defined as gathering of entity student. So that can be said that by entity show at individual an object, while gathering of entity show at clump of individual
An entity have attribute. Attribute represent the nature of or property had by entity. This attribute differentiate between entity which is one with other entity
Relationship show the existence of relation among a number of entity coming from a number of gathering of entity different
Cardinality Relationship
Cardinality represent optimum of entity, where the entity can relation with entity at gathering of entity other
Type of cardinality relationship
One to One
An entity in gathering of entity A attributed to at most one entity in B entity in gathering and entity in gathering of entity B attributed to at most one entity in gathering of entity A
One to Many
An entity in gathering of entity A attributed to more than one entity in gathering of entity B, and entity in gathering of entity B can only be attributed to at most one entity in gathering of entity A
Many to One
An entity in gathering of entity A attributed to at most one entity in gathering of entity B, and entity in gathering of entity B can be attributed to more than one entity in gathering of entity A
Many to Many
An entity in gathering of entity A can be attributed to more than one entity in gathering of entity B, and entity in gathering of entity B can be attributed to more than one entity in gathering of entity A
Key
Key represent one or alliance from some attribute able to differentiate all data line uniquely
If an attribute become key, hence there may not be any two or more data line of equal value
Type of key :
Super Key
Candidate Key
Primary Key
Diagram Entity-Relationship (Diagram E-R)
An database, can be depicted graph with an diagram of E-R
Notation of E-R :
Square of length, depicting gathering of entity
-
Elliptical, depicting attributes (functioning attribute as key highlighted)
Ramble, depicting gathering of relationship
Line, depicting attribute relation to gathering and entity of entity to gathering of relationship
-
Relationship cardinality can be depicted with many line him branch or with usage of number, 1 for relationship one, n for relationship many
Step making of Diagram E-R
Identifying and specifying entire / all gathering of entity to involve
Determining attributes of key from each gathering of entity
-
Identifying and specifying entire / all relationship gathering among gathering of entity existing along with key foreign
Determining degree of cardinality to each relationship gathering
-
Equipping gathering of entity relationship gathering and with attribute of descriptive (non key)
