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

In ER Model, relationship exits between two entities.
Types :
(i) one-to-one Relationship,
(ii) one-to-many Relationship,
(iii) many-to-many Relationship.

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.

COMMIT Command is used to make permanent changes done by transaction.

ACID Properties :
(i) The acronym stands for Atomicity, Consistency, Isolation and Durability.
(ii) Atomicity follows the thumb rule "All (or) Nothing" while updating the data in database for the user performing the update operation.
(iii) Consistency ensures that the changes in data value to be constant at any given instance. Isolation property is needed during concurrent transaction.
(iv) Durability is defined as the system is ability to recover all committed transactions during the failure of storage or the system

DDL Commands :
(i) CREATE :
Syntax : CREATE database database name; 
(ii) DROP
Syntax : DROP database databasename;
DML Commands:
(i) INSERT 
Syntax: INSERT INTO table name (column 1, column 2, column 3) VALUES (value 1, value 2, value 3);
(ii) UPDATE
Syntax: UPDATE tablename
SET column 1 = "new value"
Where column2="value2";

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.

i). Data Duplications : Same data is used be multiple resources for processing, thus created multiple copies of same data wasting the spaces.
ii). High Maintenance : Access control and verifying data consistency needs high maintenance cost.
iii). Security : Less security provided to the data.

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