SQL

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What is SQL?

SQL stands for Structured Query Language. This is structured based query language which is used to read/write data on relational database management system. It is a database language which is used for database creation, deletion, fetching and modifying.
To accomplish query language, you need database. Example - Oracle, MySQL, SQL Server, etc.

Use of SQL

  • To insert data
  • To update data
  • To retrieve data
  • To delete data

Simple rules of SQL

  • SQL is not case sensitive, means you can write query in upper case, lower case or camel case.
  • We can write a single SQL statement in one or multiple line.

Example of simple SQL statement

Select * from table_name;
where every sql statement is ended with semicolon(;) .

SQL data types

Being IT student or working in IT firm, you must have heard about data types which is used in every programming language. It is very similar to it.

Data types are used to illustrate type of data that can be stored in the database.
Example - If we want to store characters then we will declare column as a string data type.

Data types list - Int, float, char, varchar, numeric, text, date, time, timestamp, Image, Binary, decimal

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