Introduction to SQL

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This article will feed you with knowledge on the topic Introduction to SQL. SQL stands for Structured Query Language and pronounced as “Sequel”. Database is accessed using SQL statement, which is an ANSI (American National Standards Institute) standard”. SQL is used to create and query databases i.e. creating, storing, accessing and manipulating the data. Due to its loose structure and flexibility, SQL is considered as a handy tool for building dynamic web applications.

Introduction to SQL

Features of SQL :-

  1. SQL stands for Structured Query Language and is used to communicate with databases.
  2. SQL is NOT case sensitive i.e. SELECT is the same as select.
  3. SQL is efficient, easy to use and learn.
  4. SQL is used to create new databases.
  5. SQL is used to create new tables in a database.
  6. SQL is used to create views, stored procedures and functions in a database.
  7. SQL is used to drop tables and databases.
  8. SQL is used to execute queries and retrieve data from a database.
  9. SQL is used to insert, delete and update records in a database.
  10. SQL is used to set permissions on tables, procedures, and views.

SQL Commands :-

SQL Commands
Statement Language Description
Insert Data Manipulation Language (DML) Add new rows (records).
Update Modifies the existing rows in a table.
Delete  Delete the rows from a table.
Merge  Merge rows from the tables.
 Create Data Definition Language (DDL) Creates a new table, a view of a table, or other object in database.
 Alter Modifies an existing database object, such as a table.
 Drop Deletes an entire table, a view of a table or other object in the database.
 Truncate Removes all rows from a table as well as data storage space used by that table.
 Rename Rename a table.
 Commit Transaction Control Language (TCL) Commits the changes made by DML.
 Rollback  Rollback the changes made by DML.
 Savepoint Create a check point.
 Grant Data Control Language (DCL) Gives a privilege to user.
 Revoke  Takes back privileges granted from user
 Select  Data Query Language (DQL) Retrievesrecords from one or more tables.

Basic Data Types in SQL are :-

Basic Data Types

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3 COMMENTS

  1. This is a very lucide and crispy introduction to the subject..
    Intellegible to non-technical aspirants too…
    Thanks Sharma ji!

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