Structured Query Language, Study notes of Database Management Systems (DBMS)

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SQL TYPES

SQL Types

• (^) What is SQL?
• (^) MySQL Database
• (^) SQL Types
  • (^) Data Definition Language (DDL)

Data Manipulation Language (DML)

• (^) Data Control Language (DCL)
• (^) Transaction Control Language (TCL)

MySQL Database

To Create Database:

Syntax:

CREATE DATABASE database_name;

Example:

CREATE DATABASE srishakthi;

To Select Database:

Select Database is used in MySQL to select a particular database to work with. This

query is used when multiple databases are available with MySQL Server.

Syntax:

USE database_name;

Example:

USE srishakthi;

MySQL Database

To Show/List Databases:

Syntax:

SHOW DATABASES;

SHOW DATABASES LIKE pattern;

Example:

SHOW DATABASES LIKE “%thi”;

To Remove/Drop Database:

MySQL database can be easily removed with the MySQL DROP DATABASE command. It

deletes all the tables of the database along with the data permanently.

Syntax:

DROP DATABASE database_name;

Example:

DROP DATABASE srishakthi;

MySQL Database

MySQL Database

Data Definition Language (DDL)

CREATE

It is used to create a table.

Syntax:

CREATE TABLE TableName(Column1 datatype, Column2 datatype, ColumnN datatype);

Example:

Data Definition Language (DDL)

ALTER

This command is used to delete, modify or add constraints or columns in an

existing table.

To Add a Column:

ALTER TABLE TableName ADD ColumnName Datatype;

Data Definition Language (DDL)

To remove a column:

ALTER TABLE TableName DROP COLUMN ColumnName; (OR)

ALTER TABLE TableName DROP ColumnName;

Data Definition Language (DDL)

To modify a column:

ALTER TABLE TableName MODIFY ColumnName NewDatatype;

Data Definition Language (DDL)

TRUNCATE

This command is used to delete the information present in the table but does not

delete the table.

Syntax:

TRUNCATE TABLE TableName;

Example:

Data Definition Language (DDL)

DROP

This statement is used to drop an existing table. When you use this statement,

complete information present in the table will be lost.

Syntax:

DROP TABLE TableName;

Example:

Data Manipulation Language (DML)

INSERT

It is used to insert new records into the table.

Syntax:

INSERT INTO TableName VALUES (Value1, Value2, Value3, ...);

Example:

Data Manipulation Language (DML)

INSERT

It is used to insert new records into the table.

Syntax: (Specific Column Insertion)

INSERT INTO TableName (Column1, Column2, Column3, ...,ColumnN)

VALUES (value1, value2, value3, ...);

Example: