Tuesday, 31 May 2011

Coding to get nth record in sql server

for 10 th record

select top 1 * from (select top 10 * from dEmployeenew order by 1 desc)ac

choose 10 with nth

How to convert from string to date / datetime? in sql server

Execute the following T-SQL scripts in Microsoft SQL Server Manangement Studio Query Editor to demonstrate T-SQL convert and cast functions in transforming string date, string time & string datetime data to datetime data type. T-SQL date / datetime functions usage examples are presented as well.

-- SQL Server string to date / datetime conversion - datetime string format sql server

-- MSSQL string to datetime conversion - convert char to date - convert varchar to date

-- Subtract 100 from style number (format) for yy instead yyyy (or ccyy with century)

SELECT convert(datetime, 'Oct 23 2012 11:01AM', 100) -- mon dd yyyy hh:mmAM (or PM)

SELECT convert(datetime, 'Oct 23 2012 11:01AM') -- 2012-10-23 11:01:00.000



-- Without century (yy) string date conversion - convert string to datetime function

SELECT convert(datetime, 'Oct 23 12 11:01AM', 0) -- mon dd yy hh:mmAM (or PM)

SELECT convert(datetime, 'Oct 23 12 11:01AM') -- 2012-10-23 11:01:00.000



-- Convert string to datetime sql - convert string to date sql - sql dates format

-- T-SQL convert string to datetime - SQL Server convert string to date

SELECT convert(datetime, '10/23/2016', 101) -- mm/dd/yyyy

SELECT convert(datetime, '2016.10.23', 102) -- yyyy.mm.dd

SELECT convert(datetime, '23/10/2016', 103) -- dd/mm/yyyy

SELECT convert(datetime, '23.10.2016', 104) -- dd.mm.yyyy

SELECT convert(datetime, '23-10-2016', 105) -- dd-mm-yyyy

-- mon types are nondeterministic conversions, dependent on language setting

SELECT convert(datetime, '23 OCT 2016', 106) -- dd mon yyyy

SELECT convert(datetime, 'Oct 23, 2016', 107) -- mon dd, yyyy

-- 2016-10-23 00:00:00.000

SELECT convert(datetime, '20:10:44', 108) -- hh:mm:ss

-- 1900-01-01 20:10:44.000



-- mon dd yyyy hh:mm:ss:mmmAM (or PM) - sql time format - SQL Server datetime format

SELECT convert(datetime, 'Oct 23 2016 11:02:44:013AM', 109)

-- 2016-10-23 11:02:44.013

SELECT convert(datetime, '10-23-2016', 110) -- mm-dd-yyyy

SELECT convert(datetime, '2016/10/23', 111) -- yyyy/mm/dd

-- YYYYMMDD ISO date format works at any language setting - international standard

SELECT convert(datetime, '20161023')

SELECT convert(datetime, '20161023', 112) -- yyyymmdd

-- 2016-10-23 00:00:00.000

SELECT convert(datetime, '23 Oct 2016 11:02:07:577', 113) -- dd mon yyyy hh:mm:ss:mmm

-- 2016-10-23 11:02:07.577

SELECT convert(datetime, '20:10:25:300', 114) -- hh:mm:ss:mmm(24h)

-- 1900-01-01 20:10:25.300

SELECT convert(datetime, '2016-10-23 20:44:11', 120) -- yyyy-mm-dd hh:mm:ss(24h)

-- 2016-10-23 20:44:11.000

SELECT convert(datetime, '2016-10-23 20:44:11.500', 121) -- yyyy-mm-dd hh:mm:ss.mmm

-- 2016-10-23 20:44:11.500


-- Style 126 is ISO 8601 format: international standard - works with any language setting

SELECT convert(datetime, '2008-10-23T18:52:47.513', 126) -- yyyy-mm-ddThh:mm:ss(.mmm)

-- 2008-10-23 18:52:47.513


-- Convert DDMMYYYY format to datetime - sql server to date / datetime

SELECT convert(datetime, STUFF(STUFF('31012016',3,0,'-'),6,0,'-'), 105)

-- 2016-01-31 00:00:00.000

-- SQL Server T-SQL string to datetime conversion without century - some exceptions
-- nondeterministic means language setting dependent such as Mar/Mär/mars/márc

SELECT convert(datetime, 'Oct 23 16 11:02:44AM') -- Default

SELECT convert(datetime, '10/23/16', 1) -- mm/dd/yy U.S.

SELECT convert(datetime, '16.10.23', 2) -- yy.mm.dd ANSI

SELECT convert(datetime, '23/10/16', 3) -- dd/mm/yy UK/FR

SELECT convert(datetime, '23.10.16', 4) -- dd.mm.yy German

SELECT convert(datetime, '23-10-16', 5) -- dd-mm-yy Italian

SELECT convert(datetime, '23 OCT 16', 6) -- dd mon yy non-det.

SELECT convert(datetime, 'Oct 23, 16', 7) -- mon dd, yy non-det.

SELECT convert(datetime, '20:10:44', 8) -- hh:mm:ss

SELECT convert(datetime, 'Oct 23 16 11:02:44:013AM', 9) -- Default with msec

SELECT convert(datetime, '10-23-16', 10) -- mm-dd-yy U.S.

SELECT convert(datetime, '16/10/23', 11) -- yy/mm/dd Japan

SELECT convert(datetime, '161023', 12) -- yymmdd ISO

SELECT convert(datetime, '23 Oct 16 11:02:07:577', 13) -- dd mon yy hh:mm:ss:mmm EU dflt

SELECT convert(datetime, '20:10:25:300', 14) -- hh:mm:ss:mmm(24h)

SELECT convert(datetime, '2016-10-23 20:44:11',20) -- yyyy-mm-dd hh:mm:ss(24h) ODBC can.

SELECT convert(datetime, '2016-10-23 20:44:11.500', 21)-- yyyy-mm-dd hh:mm:ss.mmm ODBC

Preventing the Drop and Alter table in Sql Server Using DDL Trigger

In the following example, DDL trigger safety will fire whenever a DROP_TABLE or ALTER_TABLE
event occurs in the database.

CREATE TRIGGER safety
ON DATABASE
FOR DROP_TABLE, ALTER_TABLE
AS
PRINT 'You must disable Trigger "safety" to drop or alter tables!'
ROLLBACK

Difference between sp_executesql and EXEC() in Sql Server

EXEC() - whose first parameter is a parameterized SQL statement.
sp_executesql - The second parameter is a parameter-list declaration, similar to the parameter
list present in the declaration of a stored procedure.

If the malicious user enters a value as Sql Injection EXEC() execute the maliculous code
but sp_executesql It will search for the value ' or '1'='1 as product name in the database.
Thus preventing SQL Injection attacks.