SQL – Introduction

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  • Structured Query Language is used to store the data, manipulate the data or delete the data from the database.
  • SQL is also called SEQUEL language.

DATA:

  • Data is a collection of functions or
  • Data is a raw fact, which describes the properties of the object or
  • Data is a raw fact, which describes the attributes of the entity.

DATABASE:

  • A database is a place or medium where we can store data in a systematic and organized manner.
  • we use one special operation i.e., CRUD operation
  • C – Create/Insert
  • R – Read/Retrieve
  • U – Update/Modify
  • D – Delete/Drop

DBMS(Database Management System):

  1. DBMS is a signature which is used to maintain and manage the data in that database.
  2. In DBMS we have two features.
    • Security
    • Authorization
  3. In DBMS to communicate with the database, we use Query Language.
  4. In DBMS we store the data in the form of file format.
  • There is a drawback in DBMS i.e., there is a wastage of time as well as memory.
  • To overcome the drawback of DBMS we are using RDBMS.

RDBMS(Relational Database Management System):

  • RDBMS is a type of DBMS software, which is used to maintain and manage the data in the database.
  • In RDBMS we have two features.
    • Security
    • Authorization
  • To communicate with the database, we are using structures Query Language.
  • In RDBMS, we store the data in the form of a table.

TABLE:

  • The logical arrangement of rows as well as columns.
  • The horizontal section is known as rows and vertical section is known as columns.
  • The interaction between the horizontal and vertical section is called as cell.

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