installation of SQL server and SSMS
-----------------------------------

Datatypes in SQL
----------------

Classification of datatypes in SQL server
-----------------------------------------


CHAR
	ASCII
		char
		varchar
		varchar(max)
	UNICODE
		nchar
		nvarchar
		nvarchar(max)

INTIGER
	tinyint
	smallint
	int
	bigint

FLOAT
	decimal(p,s)

CURRENCY
	smallmoney
	money

DATE
	date
	time
	datetime

BINARY
	binary
	varbinary
	varbinary(max)



char(size):-
----------
=> allows character data upto 8000 characters
=> recommended for fixed length character columns.

ex:- NAME char(10)  -> into this name 10 characters allowed.

Sachin----  
In above name 'Sachin' takes 6 bytes of space  remaining 4 bytes are wasted.
In case of char extra bytes are wasted.

ravi------
    wasted

=>in char data type extra bytes are wasted so don't use char data types for variable length columns and use char datatype of fixed length columns.

fixed length examples:-  
state_code  =>contains =>   char(2)
AP
TS
MH

country_code => contains  => char(3)
IND
USA
UAE



varchar(size) :-
----------------

=>allows character data upto 8000 chars
=> recommended for variable length columns.

	ex :-  NAME VARCHAR(10)
		Sachin----
		      released
=>In case of VARCHAR extra bytes are released.




varchar(max) :-
--------------
=>Allows character data upto 2GB.
ex:- text varchar(max)



NOTE:char/varchar/varchar(max) allows ASCII characters(256 chars) that includes a-z,A-Z,0-9,special characters.



nchar/nvarchar/nvarchar(max):-
------------------------------
=> n stands for National
=> Allows unicode characters
=> UNICODE contains 65,536 chars.
=> It includes characters of diffrent languages.



Integer types:-
---------------
=> Allows numbers without decimal part.


tinyint   1 bytes    0 to 255
smallint  2 bytes    -32768 to 32767
int       4 bytes    -2,147,483,648 
			   to 
                      2,147,483,647
bigint    8 bytes    -9,223,372,036,854,775,808
			         to
		      9,223,372,036,854,775,807


Decimal(p,s):-
------------
=>Allows numbers with decimal parts.

p => precision => total no of digits.
s => scale     => no. of digits allowed after decimal.