Difference between DateTime and DateTime2 DataType

DATETIME2 is the new data type introduced in SQL Server 2008

DATETIME2 provides more seconds precision & has larger date range, a larger default fractional precision. DATETIME is limited to 3 1/3 milliseconds, while DATETIME2 can be accurate down to 100ns

Advantages of DATETIME2

DATETIME2 has a date range of "0001 / 01 / 01" through "9999 / 12 / 31" while the DATETIME type only supports year 1753-9999

Larger range of values

Better Accuracy

Smaller storage space (if optional user-specified precision is specified)

Precision, scale

                                                                                                        0 to 7 digits, with an accuracy of 100nanoseconds.

                                                                                                        The default precision is 7 digits.

Storage Size

                                                                                                        6 bytes for precision less than 3

                                                                                                        7 bytes for precision 3 and 4.

All other precision require 8 bytes.

DATETIME2 with fractional seconds precision of 3 is same as DATETIME data type. And DATETIME2 (precision of 3) uses 7 bytes of storage instead of 8 byte

If you only need the date without time part use DATE

 If you only need the time without date part use TIME

 Using DATE & TIME data types instead of DATETIME2 in above situations you save the space

Script to get the SQL Logins information

Login type descriptions

S = SQL Server user(SQL_USER)

U = Windows user(WINDOWS_USER)

G = Windows group(WINDOWS_GROUP)

A = Application role(APPLICATION_ROLE)

R = Database role(DATABASE_ROLE)

C = Certificate mapped(CERTIFICATE_MAPPED_USER)

K = Asymmetric key mapped(ASSYMETRIC_KEY_MAPPED_USER)

Using below script you can list all Login Accounts in a SQL Server

SELECT name AS Login_Name, type_desc AS Account_Type

FROM sys.server_principals 

WHERE TYPE IN ('U', 'S', 'G')

ORDER BY name, type_desc

Using below script you can list all  SQL Login Accounts (Not windows logins)  only in a SQL Server 

SELECT name

FROM sys.server_principals 

WHERE TYPE = 'S'

ORDER BY name, type_desc

Using below script you can list all Windows Login Accounts (Not SQL Logins)  only in a SQL Server 

SELECT name

FROM sys.server_principals 

WHERE TYPE = 'U'

Using below script you can list all Windows Group Login  (Not SQL Logins)  only in a SQL Server 

SELECT name

FROM sys.server_principals 

WHERE TYPE = 'G'

CREATE LOGIN of windows user and GRANT SYSADMIN Access

Using below command you can create a windows login and grant SysAdmin access. Replace DOMAIN\LOGIN with windows login name 

USE [master]

GO

CREATE LOGIN [DOMAIN\LOGIN] FROM WINDOWS WITH DEFAULT_DATABASE=[master]

GO

EXEC master..sp_addsrvrolemember @loginame = N'DOMAIN\LOGIN', @rolename = N'sysadmin'

GO

--

Thanks & Regards
Venkat Sangu

Script to disable/enable all triggers (Database Level) in a database & Enable or Disable Server level triggers (SERVER LEVEL)

Use below script to disable or enable all triggers in MyDatabase  (Database level) 

To disable all triggers, you can use following statement

use MyDatabase

sp_msforeachtable 'ALTER TABLE ? DISABLE TRIGGER all'

To enable all triggers, you can use following statement

use MyDatabase

sp_msforeachtable 'ALTER TABLE ? ENABLE TRIGGER all'

The following example disables all DDL triggers that were created at the server scope. (Server Level Triggers) 

USE master

GO

DISABLE Trigger ALL ON ALL SERVER;

GO

USE master

GO

ENABLE Trigger ALL ON ALL SERVER;

GO

How to Find a SQL Server Database Object in entire sql server

Script to find the weather an object is exist in entire sql server or not, if yes in which database it is exit. Below is the  better why to find a SQL Server object, such as a table, a procedure, or a trigger, would be to query the sysobjects system table in each and every  local database. Using below query we are searching for UdfUserAccessLevel

Declare @SqlStmt nvarchar(500)

/* drop the temporary -tblTempDBObjects table if already exists which store all objects information */

If Object_Id('tempdb..#tblTempDBObjects') is Not Null

Drop table #tblTempDBObjects

/* create temporary tblTempDBObjects table in temp db*/

Create TABLE tempdb..#tblTempDBObjects (

dbName sysname,

objName varchar(250),

objtype char(2)

)

/*assign string value of sql statement to insert all objects to variable */

Select @SqlStmt = 'sp_msforeachdb ''Insert tempdb..#tblTempDBObjects select ''''?'''' as DBName, name, xtype From ?..sysobjects'''

Exec sp_executesql @SqlStmt

/* searching for equired oj=bject in temptable --- UdfUserAccessLevel */

Select * From tempdb..#tblTempDBObjects Where objName like '%UdfUserAccessLevel%'

RETURN

Above statement will give below resultset and it contain database name, object and object type.

Validate all views in the database

There is an sp that validates the metadata and the   same sp we can use to validate

set nocount on

select ' print ''' +name +'''

exec sp_refreshview ['+name+']' + CHAR(10)+ '

go '

from sys.views

Execute  the above script it will give script to run sp_refreshview on all views. Run the scripts generated using above sql statement I will give error link below screen

DBCC CHECKIDENT

-- Create Table Script to test CHECKIDENT

CREATE TABLE DBCC_ReSeed

( ID INT IDENTITY(1,1) NOT NULL,

DateAdded DATETIME NOT NULL )

-- Inserting values to DBCC_ReSeed table

INSERT INTO DBCC_ReSeed(DateAdded) VALUES(GETDATE())

INSERT INTO DBCC_ReSeed(DateAdded) VALUES(GETDATE())

INSERT INTO DBCC_ReSeed(DateAdded) VALUES(GETDATE())

INSERT INTO DBCC_ReSeed(DateAdded) VALUES(GETDATE())

INSERT INTO DBCC_ReSeed(DateAdded) VALUES(GETDATE())

SELECT * FROM DBCC_ReSeed

--- Check the current value which produces the below output… 

DBCC CHECKIDENT ('DBCC_ReSeed', NORESEED)

---  Output like :  Checking identity information: current identity value '5', current column value '5'.

--- Now reset the identity value to 20 so that the next time when we insert data into DBCC_RdSeed table , the value will be 21…

DBCC CHECKIDENT('DBCC_ReSeed', RESEED, 20)

----- Output like :   Checking identity information: current identity value '5', current column value '20'

--  Add another row and check identity value. The row inserted will have a value of 21… 

INSERT INTO DBCC_ReSeed (DateAdded)  VALUES(GETDATE());

SELECT * FROM DBCC_ReSeed

-- Delete data in table and reset to start from 1

DELETE FROM DBCC_ReSeed

DBCC CHECKIDENT('DBCC_ReSeed')

-- After deleting data identity value didn’t reset and the value will be remain same  

---  Output like :  Checking identity information: current identity value '20', current column value '20'.

DBCC CHECKIDENT('DBCC_ReSeed', RESEED, -1)

---  Output like :  Checking identity information: current identity value '21', current column value '-1'.

INSERT INTO DBCC_ReSeed (DateAdded)  VALUES(GETDATE());

INSERT INTO DBCC_ReSeed (DateAdded)  VALUES(GETDATE());

SELECT * FROM DBCC_ReSeed

Recently executed query

Using below query you can get executed time and query text

SELECT deqs.last_execution_time AS [Time], dest.TEXT AS [Query]

FROM sys.dm_exec_query_stats AS deqs

CROSS APPLY sys.dm_exec_sql_text(deqs.sql_handle) AS dest

ORDER BY deqs.last_execution_time DESC

Results of above query

Using below query you can find the Recently excuted query for specific SPID

SELECT SDEC.[most_recent_sql_handle], DEST.[text], last_read, Last_write

FROM sys.[dm_exec_connections] SDEC

 CROSS APPLY sys.[dm_exec_sql_text](SDEC.[most_recent_sql_handle]) AS DEST

WHERE SDEC.[most_recent_session_id] = 52

Results of above query

Thanks

Venkat Sangu