SQL – Structured Query Language

What is SQL?

      SQL stands for Structured Query Language. SQL is used to communicate with a database. It is the standard language for Relational Database Management Systems (RDBMS).

        R DBMS’s that use SQL are Oracle, MySQL, Microsoft SQL Server, Access, Ingres, Sybase  etc. Although most database systems use SQL, most of them also have their own additional  extensions that are usually only used on their system.

What is a Database? 

        In general, a database consists of one or more tables. Each table is identified by a name and contain rows  and columns containing Data.

Database Management System (DBMS)

         DBMS stands for Database Management System. DBMS data is structured in database tables, fields and records. Each DBMS table consists of database table rows. Each database table row consists of one or more database table fields.

     A database management system (DBMS) is software that controls the storage, organisation, and retrieval of data. Typically, a DBMS has the following elements:

Kernel code : This code manages memory and storage for the DBMS.

Repository of metadata : This repository is usually called a data dictionary.

Query language : This language enables applications to access the data.

Relational Database Management System(R DBMS)

   R DBMS stands for Relational Database Management System store the data into collection of tables, which might be related by common fields (database table columns).

What Can SQL do?

  • SQL can create new databases
  • SQL can create new tables in a database
  • SQL can retrieve data from a database
  • SQL can execute queries against a database
  • SQL can insert records in a database
  • SQL can update records in a database
  • SQL can delete records from a database
  • SQL can create stored procedures in a database
  • SQL can create views in a database
  • SQL can set permissions on tables, procedures, and views

History :

1970 – Dr.Edger F.Ted Codd of IBM is known as father of relational databases. He described a relational model for databases.

1974 – Structured Query Language appeared.

1978 – IBM worked to develop Codd’s ideas and released a product named System/R.

1986 – IBM developed the first prototype of relational database and standardised by ANSI. The first relational database was released by Relational Software and its later becoming Oracle.

Chapters :

  1. RDBMS Concepts
  2. Types of SQL statements
  3. Data types
  4. Operators
  5. Clauses in SQL
  6. Constraints
  7. Joins & Unions
  8. Dates
  9. View, Index & Sequence
  10. SQL Functions
  11. PL / SQL
  12. Examples
  13. Questions and Answers