Every sql topic even the most complex topics like triggers stored proc were explained easily for better understanding.
Store large number of records
Share huge data set among many people
Add and edit data easily
Quick and easy to find information
Column as Attribute
Row as Entity Instance
Table as Entity
AlternateKey as UniqueKey
90% of the tables in database will be linked with another tables.
10%of the tables will be independent.
There are three types of relationships between tables
one to one
one to many
many to many
Tables can have a single / multiple relationships or may not have relationships.
Structured data – 2 dimensional data Rows,Columns
PrimaryKey in one table will be given as ForiegnKey in another table to build relationship.
PrimaryKey & ForiegnKey with relationship between them.
1 to 1 – any PrimaryKey can become ForiegnKey
1 to many employees in a department
PK of parent table will be FK in child table
Department table Deptid(PK),DeptName,
Employees Table Empid,EmpName,DeptId(FK)
many to many(students and teachers,patients & doctors,Hospital & Doctors)(TeacherId,TeacherName)(StudentId,StudentName,TeacherId)
New table will be created and extra column will be added(Bridge Table)
Doctors Table(DoctorNo(PK),Name,Qualification,Salary, DateOfJoining, DateOfResigning)
Patient Doctor Table()
SDLC-Software Development Life Cycle
Analysis & Design
Domain expert(SRS documentation)
ERD(Entity Relationship Diagram)
Peter Chan-Used to design Database
SQL server performs existence check when we create relationship.
SELF REFERENTIAL TABLES
A table which has both PrimaryKey and ForiegnKey in it & ForiegnKey refering the primary key in the same table.
You are going to learn
Who this course is for:
- Beginner who is planning to learn mysql completely