Microsoft SQL Server: Part - 1

Microsoft SQL Server: Part - 1

#microsoft #sql #sqlserver #sqlqueries

1. Download and install SQL Server Developer Edition:
https://www.microsoft.com/en-in/sql-server/sql-server-downloads

RDBMS: Client Server Concepts:
A relational database management system (RDBMS) is a database management system that is based on a relational model.
The relational model uses the basic concept of a relation or table.
RDBMS is the basis for SQL, and for database systems like MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft Access.


What is SQL?
SQL stands for Structured Query Language
SQL lets you access and manipulate databases
SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987

What Can SQL do?
SQL can execute queries against a database
SQL can retrieve data from a database
SQL can insert records in a database
SQL can update records in a database
SQL can delete records from a database
SQL can create new databases
SQL can create new tables in a database
SQL can create stored procedures in a database
SQL can create views in a database
SQL can set permissions on tables, procedures, and views

CREATE DATABASE databasename;

CREATE TABLE Person(
PersonID int,
LastName varchar(255),
FirstName varchar(255),
Address varchar(255),
City varchar(255)
);

DROP TABLE Person;

Home Work:
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Constraints:
NOT NULL - Ensures that a column cannot have a NULL value
UNIQUE - Ensures that all values in a column are different
PRIMARY KEY - A combination of a NOT NULL and UNIQUE. Uniquely identifies each row in a table
FOREIGN KEY - Prevents actions that would destroy links between tables
CHECK - Ensures that the values in a column satisfies a specific condition
DEFAULT - Sets a default value for a column if no value is specified
CREATE INDEX - Used to create and retrieve data from the database very quickly

CREATE TABLE Persons (
ID int IDENTITY(1,1) PRIMARY KEY,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Age int DEFAULT 1
);

ALTER TABLE Person ADD COLUMN Email;