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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HowTo Convert Table Values to Comma-Delimited String

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We have 2 tables related as one-to-many. How can we fetch parent table field, and child table values comma-delimited ? The function below demonstrates a technique how to convert table values into comma-delimited string with one query.


ALTER FUNCTION F_GET_STR
(@p_order_id int)
RETURNS varchar(1000)
AS
   BEGIN

   DECLARE @p_str VARCHAR(1000)
   SET @p_str = ''

   SELECT @p_str = @p_str + ',' + CAST(productid AS VARCHAR(6))
     FROM [order details]
    WHERE orderid = @p_order_id

   RETURN @p_str




END

Use this way:


SELECT orderid ,dbo.F_GET_STR(orderid) FROM orders

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