SQL (Structured Query Language)
In this blog. let’s see SQL introduction and datatypes.
Introduction
Database
The database is a collection of data or related data.
SQL performs CRUD operations on the database.
- C – create
- R – read
- U – update
- D – deleted
A Database Management system (DBMS) is software. It interfaces between Database and end-user. That is responsible for authentication concurrency, logging, backup, optimization, etc.
There are many types of databases - Relational, Hierarchical, Network, NoSQL, etc.
Examples of RDBMS
- MYSQL – opensource.
- SQL Server – Microsoft.
- Oracle – IBM.
- PostgreSQL – opensource.
Datatypes
Character data
Char is stored in max 255 bytes.
Varchar is stored in max 65535 bytes.
Character set
The Default character set is Latin1.
SHOW CHARACTER SET; -- shows Various character sets that are supported - -
Example
VARCHAR (20) CHARACTER SET utf8; -- the particular column is set to utf8 --
CREATE DATABASE student CHARACTER SET utf8; -- entire database is set to utf8 --
In this example, we used the utf8 character set. If not used utf8 character set it takes the default character set Latin1.
The Text data
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Blob stands for a binary large object. This data type is used to store large amounts of data such as images, media, files.
The Numerical data
Whole numbers
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Tinyint is used to store boolean.
The Decimal Numbers
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The Temporal data
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I hope this blog is most helpful for you.