Execute Dynamic SQL commands in SQL Server

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In some applications having hard-coded SQL statements is not appealing, because of the dynamic nature of the queries being issued against the database server. Because of this sometimes there is a need to dynamically create a SQL statement on the fly and then run that command. This can be done quite simply from the application perspective where the statement is built on the fly whether you are using ASP.NET , ColdFusion or any other programming language. But how do you do this from within a SQL Server stored procedure? SQL Server offers a few ways of running a dynamically built SQL statement. These ways are: Writing a query with parameters Using EXEC Using sp_executesql Writing a query with parameters This first approach is pretty straightforward if you only need to pass parameters into the WHERE clause of your SQL statement. Let’s say we need to find all records from the Customers table where City = ‘London’. This can be done easily as the following example shows.
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T-SQL: Leap Year Check

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There are various techniques to determine whether a given year is a leap year. The most common way which is widely taught at schools and universities is to detect whether the given year is divided by 4, 100 and not by 400, something like that.


Below is a small T-SQL function that checks for leap year while it uses more smart - shifting technique, which I advice to use where possible.


ALTER FUNCTION F_BIT_LEAP_YEAR
(@p_year SMALLINT)
RETURNS BIT
AS
BEGIN
   DECLARE @p_leap_date SMALLDATETIME
   DECLARE @p_check_day TINYINT

   SET @p_leap_date = CONVERT(VARCHAR(4), @p_year) + '0228'
   SET @p_check_day = DATEPART(d, DATEADD(d, 1, @p_leap_date))
   IF (@p_check_day = 29)
       RETURN 1

   RETURN 0 
END

Use this way:


SELECT dbo.F_BIT_LEAP_YEAR(2003)

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