Advantages:
(i) High Availability
(ii) High Performance
(iii) Robust Transactions and Support
(iv) Ease of Management
(v) Less Cost

S.No	SQL	MySQL
1.	SQL is a structured query language.	MySQL is a database software.
2.	SQL is used to query and operate a database system.	MySQL allows data handling, storing, modifying, deleting etc.

(i) A set of stored queries is known as view in SQL.
(ii) A View contains rows and columns just like a real table.

Single Valued Attribute: A single valued attribute contains only one value for the attribute and they don't have multiple numbers of values.
Multi Valued Attribute: A multi valued attribute has more than one value for that particular attribute.

Data models define how the logical structure a database is modeled. Data models define how data is connected to each other and how they are  processed andstored inside the system
Types of Data Model :
1) Hierarchical database model 
2) Network model 
3) Relational model 
4) object oriented database model

The three major parts that forms a database are Tables, Queries and Views.
(i) Tables - similar to an excel sheet, containing multiple rows and columns. Where each row is a record and each column is an attribute.
(ii) Queries - It is a question with multiple conditions posted to the database. The records in the database that satisfies the passed conditions are retrieved.
(iii) Views - A set of stored queries.

List of privileges available in MySQL

Privileges	Action Performed (If Granted)
Select_priv	User can select rows from database tables.
Insert_priv	User can insert rows into database tables.
Update_priv	User can update rows of database tables.
Delete_priv	User can delete rows of database tables.
Create_priv	User can create new tables in database
Alter_priv	User can make changes to the database structure.

In ER Model, relationship exists between two entities. Three types of relationships are available and the Entity-Relationship (ER) diagram is based on the three types listed below
(i) One-to-One relationship: Consider two entities A and B. One-to-one (1:1) relationship is said to exist in a relational database design, if 0 or 1 instance of entity A is associated with 0 or 1 instance of entity B, and 0 or 1 instance of entity B is associated with 0 or I instance of entity A.
(ii) One-to-Many relationship: Consider two entities A and B. One-to-many (1:N) relationship is said to exist in a relational database design, for 1 instance of entity A there exists 0 or 1 or many instances of entity B, but for 1 instance of entity B there exists 0 ur 1 instance of entity A.
(iii) Many-to-Many relationship: Consider two entities A and B. many-to-many (M:N) relationship is said to exist in a relational database design, for 1 instance of entity A there exists 0 or 1 or many instances of entity B, and for 1 instance of entity B there exists 0 or 1 or many instance of entity A.

Evolution of DBMS:
(i) The concept of storing the data started before 40 years in various formats.
(ii) In earlier days they have used punched card technology to store the data. Then files were used.
(ii) The file systems were known as predecessor of database system.
(iv) Various access methods in file system were indexed, random and sequential access.
The file system had more limitations like.
Data Duplication : Same data is used by multiple resources for processing, thus created multiple copies of same data wasting the spaces.
High Maintenance : Access control and verifying data consistency needs high maintenance cost.
Security : Less security provided to the data.
(v) So database systems became popular to overcome the above limitations of file system.

An attribute is the information about entity and it will describe, qualify, quantify, classify, and specify an entity.
An attribute will always have a single value, that value can be a number (or) character (or) string.
Types of Attributes: 
(1) Key Attribute
(2) Simple Attributes
(3) Composite Attributes
(4) Single Valued Attribute
(5) Multi Valued Attribute.
1 Key Attribute:- Generally a key attribute describes a unique characteristic of an entity.
2. Simple Attributes:- The Simple Attributes cannot be separated it will be having a single value for their entity.
For Example: Let us consider the name as the attribute for the entity employee and here the value for that attribute is a single value.

3. Composite Attributes:- The composite attributes can be subdivided into simple attributes without change in the meaning of that attribute.
For Example: In the above diagram the employee is the entity with the composite attribute Name
which are sub-divided into two simple attributes first and last name.
4. Single Valued Attributes:- A single valued attribute contains only one value for the attribute and they don't have multiple numbers of values.
For Example: Age- It is a single value for a person as we cannot give n number of ages for a single

5. A Multi Valued Attributes:- A multi valued attribute has more than one-value for that particular attribute.
For Example: Degree A person can hold n number of degrees so it is a multi-valued attribute.

ER Modeling basic concepts: The basic concepts of ER model consists of
1. Entity or Entity type
2. Attributes
3. Relationship
(i) Entity (or) Entity type
(i) An Entity can be real-world object (or) animation which is easily identifiable by anyone even by a common man.
(ii) Example: In a company's database Employee, HR, Manager are considered as entities, where each of these entity will be having their own attributes.An entity is represented by a rectangular box.

Types of Entity:
(a) Strong Entity
(b) Weak Entity
(c) Entity Instance
(i) Strong Entity
1. Strong entity is not depend on other entity and it will have a primary key.
2. It is represented by one rectangle.

3. For Example Roll Number. Everyone Roll Number varies and it will not be same.
(ii) Weak Entity
1. A weak entity is dependent on other entities and it doesn't have any primary key like strong entity.
2. It is represented by double rectangle.

3. For Example, "Marks" is the weak entity and there is no primary key or unique id. It is depend on the existence of the other entity.

(iii) Entity Instance
1. Instances are the values for the entity. So an Entity Instance denotes the category values for the given entity.
Entities Instances

Entities	Instances
Human	Male, Female
Animals	Dog, cats, lion
Jobs	Engineer, Doctor, Lawyer
Actors	Ajith, Vijay, Vikram
Electronics	Laptop, Mobile

2. Attributes
An attribute is the information about that entity and it will entity describe, quantity, qualify, classify and specify and entity. An attribute will always have a single value, that value can be a number or character or string.
Types of attributes :
(i) Key Attribute
(ii) Simple Attributes
(ii) Composite Attributes
(iv) Single Valued Attribute
(v) Multi Valued Attribute
3. Relationship Type
In ER Model, relationship exists between two entities. Three types of relationships are available and the Entity-Relationship (ER) diagram is based on the three types listed below
(i) One-to-One relationship: Consider two entities A and B. One-to-one (1:1) relationship is said to exist in a relational database design, if 0 or 1 instance of entity A is associated with 0 or 1 instance of entity B, and 0 or 1 instance of entity B is associated with 0 or I instance of entity A.
(ii) One-to-Many relationship: Consider two entities A and B. One-to-many (1:N) relationship is said to exist in a relational database design, for 1 instance of entity A there exists 0 or 1 or many instances of entity B, but for 1 instance of entity B there exists 0 ur 1 instance of entity A.
(iii) Many-to-Many relationship: Consider two entities A and B. many-to-many (M:N) relationship is said to exist in a relational database design, for 1 instance of entity A there exists 0 or 1 or many instances of entity B, and for 1 instance of entity B there exists 0 or 1 or many instance of entity A.
In reality one-to-one are in less usage, where as one-to-many and many-to-many are commonly used. However in relational database, many-to-many are converted into one-to-many relationships.