anxkhn/SQLBasics

A repo for basic SQL Commands

SQLBasics

A repo for basic MySQL Commands and for storing Lab Assignments.

Show Databases

SHOW DATABASES;

Create Databases

CREATE DATABASE database_name;

Use Databases

USE database_name;

Drop Databases

DROP DATABASE database_name;

Show Tables

SHOW TABLES;

Describe Table

DESCRIBE table_name

or

DESC table_name

Show Table (query)

SELECT * FROM table_name;

Create Table

CREATE TABLE table_name (
    column1 datatype,
    column2 datatype,
    column3 datatype,
   ....
);

Describe Structure of a Table

DESCRIBE table_name;

Drop Table

DROP TABLE table_name;

Truncate Table

TRUNCATE TABLE table_name;

Alter Table (Add Column)

ALTER TABLE table_name
ADD column_name datatype;

Alter Table (Drop Column)

ALTER TABLE table_name
DROP COLUMN column_name;

Alter Table (Modify Column)

ALTER TABLE table_name
MODIFY COLUMN column_name datatype;

or

ALTER TABLE table_name
ALTER COLUMN column_name datatype;

Constraints

CREATE TABLE Persons (
    ID int PRIMARY KEY,
    FirstName varchar(255) NOT NULL,
    AadharNo int UNIQUE,
    City varchar(255) DEFAULT 'Mumbai',
    Personid int IDENTITY(1,1)
    Age int,
    CHECK (Age>=18)
);

Constraints - Foreign Key

CREATE TABLE Orders (
    OrderID int PRIMARY KEY,
    OrderNumber int NOT NULL,
    ID int,
    FOREIGN KEY (ID) REFERENCES Persons(ID)
);

SQL Queries

Client_master
product_master
salesman_master
sales_order
sales_order_details
challan_header
challan_details

Assignment List

Feel free to refer my personal code repos.

Create ISSUE if you find any. PULL REQUESTS are welcomed.
Please use it responsibly. Thank you!