Entity Relationship Diagram (ERD)
What is ERD ?
ERD is diagram data for facilitate manufacture database, in this diagram we can determined type data before we create table.
ERD definition
Entity => object
Attribute => Detailed information owned by the object
Relationship => relationship between object
Types of relationship
One to One ( 1 : 1 )
One to Many ( 1 : N )
Many to Many ( M : N )
Preparation before create ERD
Create case study ( today i want to take a case study of a class and student )
Identification entity required
Specify the attribute type
Specify relation entity
Create ERD with draw.io
Let's Practice
Open draw.io
Create 5 list
List for learner, mentor, profil_mentor, project and class.
PK => Primary Key
o => many
| => one
Go to terminal
Create All Table
Insert data into table
See final the table from the merge of all tables
TABLES Relationships
Mentor to profil_mentor => 1 : 1
Mentor to Class => 1 : M
Class to learner => M : 1
Project to Mentor => N : M
Project to Learner => N : M
