SQL DATEDIFF & DATEADD Functions

SQL DATEDIFF Function

Returns the number of date and time boundaries crossed between two dates

SQL DATEDIFF Syntax
DATEDIFF ( DatePart , StartDate , EndDate )

DECLARE @StartDate DATETIME
DECLARE @EndDate DATETIME
SET @StartDate ='2007-06-05'
SET @EndDate ='2007-08-05'

SELECT DATEDIFF(Year, @StartDate, @EndDate) AS NewDate
Return Value = 0 Year


SELECT DATEDIFF(quarter, @StartDate, @EndDate) AS NewDate
Return Value = 1 quarter


SELECT DATEDIFF(Month, @StartDate, @EndDate) AS NewDate
Return Value = 2 Month


SELECT DATEDIFF(dayofyear,@StartDate, @EndDate) AS NewDate
Return Value = 61 day


SELECT DATEDIFF(Day, @StartDate, @EndDate) AS NewDate
Return Value = 61 Day


SELECT DATEDIFF(Week, @StartDate, @EndDate) AS NewDate
Return Value = 9 Week


SELECT DATEDIFF(Hour, @StartDate, @EndDate) AS NewDate
Return Value = 1464 Hour


SELECT DATEDIFF(minute, @StartDate, @EndDate) AS NewDate
Return Value = 87840 minute


SELECT DATEDIFF(second, @StartDate, @EndDate) AS NewDate
Return Value = 5270400 second


DECLARE @StartDate DATETIME
DECLARE @EndDate DATETIME
SET @StartDate ='2007-06-05'
SET @EndDate ='2007-06-06'

SELECT DATEDIFF(millisecond, @StartDate, @EndDate) AS NewDate
Return Value = 86400000 millisecond

SQL DATEDIFF Function
SqlTutorials

Posted by Emil Chang at 6:18 AM 12 comments

Labels: SQL DateADD and DateDiff, SQL Dynamic Get Last and First Day

Monday, June 4, 2007

SQL DATEADD Function

Returns a new datetime value based on adding an interval to the specified date.

SQL DATEADD Syntax
DATEADD ( datepart , number, date )


DECLARE @DateNow DATETIME
SET @DateNow='2007-06-04'
SELECT DATEADD(Year, 3, @DateNow) AS NewDate
Return Value = 2010-06-04 00:00:00.000


SELECT DATEADD(quarter, 3, @DateNow) AS NewDate
Return Value = 2008-03-04 00:00:00.000


SELECT DATEADD(Month, 3, @DateNow) AS NewDate
Return Value = 2007-09-04 00:00:00.000


SELECT DATEADD(dayofyear,3, @DateNow) AS NewDate
Return Value = 2007-06-07 00:00:00.000


SELECT DATEADD(Day, 3, @DateNow) AS NewDate
Return Value = 2007-06-07 00:00:00.000


SELECT DATEADD(Week, 3, @DateNow) AS NewDate
Return Value = 2007-06-25 00:00:00.000


SELECT DATEADD(Hour, 3, @DateNow) AS NewDate
Return Value = 2007-06-04 03:00:00.000


SELECT DATEADD(minute, 3, @DateNow) AS NewDate
Return Value = 2007-06-04 00:03:00.000


SELECT DATEADD(second, 3, @DateNow) AS NewDate
Return Value = 2007-06-04 00:00:03.000


SELECT DATEADD(millisecond, 3, @DateNow) AS NewDate
Return Value = 2007-06-04 00:00:00.003

SQL Case

http://sqltutorials.blogspot.com

SQL Case evaluates a list of conditions and returns one possible result expressions.

CASE has two formats:
1. Simple CASE Function - Compares an expression to determine the result.
2. Searched CASE Function - Evaluates a set of Boolean expressions to determine the result.

CASE Syntax
1. Simple CASE function:
CASE input_expression
WHEN when_expression THEN Result
ELSE result_expression
END

2. Searched CASE function:
CASE
WHEN Boolean_expression THEN Result
ELSE result_expression
END

1. Simple CASE Function
Evaluates input_expression and find the match with when_expression. If found, it will return the Result and if not found, it will return the ELSE result_expression if an ELSE clause is specified, or a NULL value if no ELSE clause is specified.

DECLARE @Type varchar(20)
SET @Type = 'Programming'

SELECT
CASE @Type
WHEN 'Sql' THEN 'sqltutorials.blogspot.com'
WHEN 'Programming' THEN 'programmingschools.blogspot.com'
WHEN 'Travel' THEN 'travelyourself.blogspot.com'
ELSE 'Not yet categorized'
END
Value = programmingschools.blogspot.com

If SET @Type = 'Picture', then Return value = Not yet categorized



2.Searched CASE Function
Evaluates Boolean_expression for each WHEN clause and returns result_expression of the first Boolean_expression that evaluates to TRUE.
If no Boolean_expression evaluates to TRUE, SQL Server returns the ELSE result_expression if an ELSE clause is specified, or a NULL value if no ELSE clause is specified.

DECLARE @Price integer
SET @Price = (20-9)

SELECT
CASE
WHEN @Price IS NULL THEN 'Not yet priced'
WHEN @Price < color="#ff0000">THEN 'Very Reasonable Price'
WHEN @Price >= 10 AND @Price < color="#ff0000">THEN 'Reasonable Price'
ELSE 'Expensive book!'
END
Value = Reasonable Price

SQL CAST and CONVERT

SQL CAST and CONVERT

It converts an expression from one data type to another.
CAST and CONVERT have similar functionality.

SQL CAST and CONVERT Syntax
Using CAST:
CAST ( expression AS data_type )

Using CONVERT:
CONVERT ( data_type [ ( length ) ] , expression [ , style ] )

Example of SQL Cast and Convert

SQL Cast and Convert - String
SELECT SUBSTRING('CAST and CONVERT', 1, 3)
Return Value = CAS (it get from index 1 to 3)

SELECT CAST('CAST and CONVERT' AS char(3))
Return Value = CAS (it get 3 char only)


SQL Cast and Convert - Date Time
-Converting date time to character data(vachar)
-The default values (style 0 or 100, 9 or 109, 13 or 113, 20 or 120, and 21 or 121) always return the Without century year(yy).
-Add 100 to a style value to get a four-place year that includes the century year(yyyy).
-Below is example for converting 1 format of date time to different format of date time, so that it can be use in various condition.

Value of current Date Time GETDATE()
SELECT (GETDATE()) = 2007-06-06 23:41:10.153


SELECT CONVERT(varchar,GETDATE(),0)
Return Value = Jun 6 2007 11:07PM
SELECT CONVERT(varchar,GETDATE(),100)
Return Value = Jun 6 2007 11:07PM


SELECT CONVERT(varchar,GETDATE(),1)
Return Value = 06/06/07
SELECT CONVERT(varchar,GETDATE(),101)
Return Value = 06/06/2007


SELECT CONVERT(varchar,GETDATE(),2)
Return Value = 07.06.06
SELECT CONVERT(varchar,GETDATE(),102)
Return Value = 2007.06.06


SELECT CONVERT(varchar,GETDATE(),3)
Return Value = 06/06/07
SELECT CONVERT(varchar,GETDATE(),103)
Return Value = 06/06/2007


SELECT CONVERT(varchar,GETDATE(),4)
Return Value = 06.06.07
SELECT CONVERT(varchar,GETDATE(),104)
Return Value = 06.06.2007


SELECT CONVERT(varchar,GETDATE(),5)
Return Value = 06-06-07
SELECT CONVERT(varchar,GETDATE(),105)
Return Value = 06-06-2007


SELECT CONVERT(varchar,GETDATE(),6)
Return Value = 06 Jun 07
SELECT CONVERT(varchar,GETDATE(),106)
Return Value = 06 Jun 2007


SELECT CONVERT(varchar,GETDATE(),7)
Return Value = Jun 06, 07
SELECT CONVERT(varchar,GETDATE(),107)
Return Value = Jun 06, 2007


SELECT CONVERT(varchar,GETDATE(),8)
Return Value = 23:38:49
SELECT CONVERT(varchar,GETDATE(),108)
Return Value = 23:38:49


SELECT CONVERT(varchar,GETDATE(),9)
Return Value = Jun 6 2007 11:39:17:060PM
SELECT CONVERT(varchar,GETDATE(),109)
Return Value = Jun 6 2007 11:39:17:060PM


SELECT CONVERT(varchar,GETDATE(),10)
Return Value = 06-06-07
SELECT CONVERT(varchar,GETDATE(),110)
Return Value = 06-06-2007


SELECT CONVERT(varchar,GETDATE(),11)
Return Value = 07/06/06
SELECT CONVERT(varchar,GETDATE(),111)
Return Value = 2007/06/06


SELECT CONVERT(varchar,GETDATE(),12)
Return Value = 070606
SELECT CONVERT(varchar,GETDATE(),112)
Return Value = 20070606


SELECT CONVERT(varchar,GETDATE(),13)
Return Value = 06 Jun 2007 23:40:14:577
SELECT CONVERT(varchar,GETDATE(),113)
Return Value = 06 Jun 2007 23:40:14:577


SELECT CONVERT(varchar,GETDATE(),14)
Return Value = 23:40:29:717
SELECT CONVERT(varchar,GETDATE(),114)
Return Value = 23:40:29:717


SELECT CONVERT(varchar,GETDATE(),20)
Return Value = 2007-06-06 23:40:51
SELECT CONVERT(varchar,GETDATE(),120)
Return Value = 2007-06-06 23:40:51


SELECT CONVERT(varchar,GETDATE(),21)
Return Value = 2007-06-06 23:41:10.153
SELECT CONVERT(varchar,GETDATE(),121)
Return Value = 2007-06-06 23:41:10.153


SELECT CONVERT(varchar,GETDATE(),126)
Return Value = 2007-06-06T23:41:10.153


SELECT CONVERT(varchar,GETDATE(),131)
Return Value = 21/05/1428 11:41:10:153PM

LastDay_PreviousMonth

SELECT DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE()),0))
LastDay_PreviousMonth
----Last Day of Current Month
SELECT DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE())+1,0))
LastDay_CurrentMonth
----Last Day of Next Month
SELECT DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE())+2,0))
LastDay_NextMonth
--Last Day of Any Month and Year
DECLARE @dtDate DATETIME
SET @dtDate = '8/18/2007'
SELECT DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,@dtDate)+1,0))
LastDay_AnyMonth

WCF EndPoint

Every service must have Address that defines where the service resides, Contract that defines what the service does and a Binding that defines how to communicate with the service. In WCF the relationship between Address, Contract and Binding is called Endpoint.

The Endpoint is the fusion of Address, Contract and Binding.