SQL SERVER INTERVIEW QUESTION AND ANSWER PART2

Q:- What is SQL?
Ans:- SQL(Structured Query Language) is a standard language for
accessing and manipulating databases.
It is a standard which is given by American National Standard Institute(ANSI)
 in 1986 and of the International Organization for Standardization(ISO)
 in 1987.

Datatypes in SQL SERVER---
When we create any table in Sql Server,before it we have to know that what is table?
Actually table is combination of raw and column and
 in a database table each column is required to have a name and a
data type.

The data type helps for SQL to understand what type of
data is expected inside of each column,



Character strings
char[n]
Desc: Fixed-length, Non-Unicode character data with a length of n bytes. Value of n will be 1 through 8,000.

varchar [ n | max  ]
Desc: Variable-length, non-Unicode character data. n can be a value from 1 through 8,000. max shows that the maximum storage size is 2^31-1 bytes.


text
Desc: Variable-length, non-Unicode data in the code page of the server and with a maximum length of (2^31-1 (2,147,483,647)) chars.
When the server code page uses double-byte chars, the storage is still (2,147,483,647) bytes.
 Depending on the character string, the storage size may be less than 2,147,483,647 bytes.
Will be removed in a future version of Microsoft SQL Server, use varchar(max) instead.


Unicode Character strings
nchar[n]
Desc: Fixed-length, Unicode character data of n characters. n must be a value from 1 through 4,000.
The storage size is two times n bytes.


nvarchar [ n | max ]
Desc:Variable-length Unicode character data. n can be a value from 1 through 4,000 characters. max indicates that the maximum storage size is 2^31-1 bytes. The storage size, in bytes, is two times the number of characters entered + 2 bytes.


ntext
Desc: Variable-length, Unicode data with a maximum length of 2^30 – 1 (1,073,741,823) characters.
Storage size, in bytes, is two times the number of characters entered.
Will be removed in a future version of Microsoft SQL Server, use nvarchar(max) instead.


Binary strings
binary [  n  ]
Desc: Fixed-length, binary data with a length of n bytes, where n is a value from 1 through 8,000. The storage size is n bytes.


varbinary [ n | max ]
Desc:Variable-length, binary data. n can be a value from 1 through 8,000 bytes. max indicates that the maximum storage size is 2^31-1 bytes. The storage size is the actual length of the data entered + 2 bytes.


image
Desc: Variable-length, binary data from 0 through 2^31-1 (2,147,483,647) bytes.
Will be removed in a future version of Microsoft SQL Server, use varbinary(max) instead.


Numerics
bigint
Desc: 8 bytes, The bigint data type is intended for use when integer values might exceed the range that is supported by the int data type.


int
Desc: 4 bytes, The int data type is the primary integer data type in SQL Server.


smallint
Desc: 2 bytes


tinyint
Desc: 1 byte


bit
Desc: An integer data type that can take a value of 1, 0, or NULL.


numeric[p,s], decimal[p,s]
Desc: Numeric data types that have fixed precision and scale.


money
Desc:Data types that represent monetary or currency values. The money
 and smallmoney data types are accurate to a ten-thousandth of the
monetary units that they represent.


smallmoney
Desc:Data types that represent monetary or currency values. The money
 and smallmoney data types are accurate to a ten-thousandth of the monetary units that they represent.

float[n]
Desc:Approximate-number data types for use with floating point numeric data. Floating point data is approximate; therefore, not all values in the data type range can be represented exactly.

real

Date and Time
Date
Desc: Defines a date.

Datetime
Desc: Defines a date that is combined with a time of day with fractional seconds that is based on a 24-hour clock.

Datetime2
Desc:Defines a date that is combined with a time of day that is based on 24-hour clock.
datetime2 can be considered as an extension of the existing datetime type that has a larger date range, a larger default fractional precision, and optional user-specified precision.
Oracle:timestamp

Datetimeoffset
Desc: Defines a date that is combined with a time of a day that has time zone awareness and is based on a 24-hour clock.
Oracle:timestamp with time zone

Smalldatetime
Desc:Defines a date that is combined with a time of day. The time is based on a 24-hour day, with seconds always zero (:00) and without fractional seconds.
Oracle:date, The value for seconds is returned as 0

time
Desc: Defines a time of a day. The time is without time zone awareness and is based on a 24-hour clock.