SQL is mostly used for stroing structural data but also in recent years it is capable enough to store unstructure data. You can retrive any information from SQL by writing queries. SQL queries are devided into four parts.
Name itself Suggests that these quries are use for describeing the dataabase schema. Where you can create and design the database according to your project requirements.
These queries are most important for making modifications in data or change the incorrect entries within the databases.
Database is nothing but the information you stored in the system which have high chance for exploite. These queries help your database secure and manage its effectiveness.
There are few chance that you are executing queries which can make impact on your database and it can be very painfull to prevent these kind of situations there are transaction control queries which make your life easier.
Enjoy , Start pulling: