SQL - What is sp_executesql system stored procedure in SQL Server

In this blog, we will discuss about sp_executesql stored procedure and what advantage sp_executesql stored procedure have it over EXEC.

sp_executesql is system stored procedure, it is used to execute the SQL script like EXEC but sp_executesql allows for SQL statement to be parameterized as instead of embedding or injecting it into SQL code so it stops any SQL Injection possibility.

There are some other difference between Exec and sp_executesql

sp_executesql	EXEC
Allow for statement to be parameterized	There is no option for parameterize column
No Risk of SQL Injection	High Risk of SQL Injection
Strongly typed parameters	No Strongly typed parameters
Performance Benefits - Cache an execution plane on first run	Create an execution plan for each run

Here is an example of sp_executesql:

CREATE PROCEDURE dbo.usp_validate_user

     @UserName as varchar(10),

     @Password as varchar(10)

AS

BEGIN

    

     declare @sqlString as varchar(max)

     SET @sqlString = 'Select id from dbo.Users Where UserName = @UserName and password = @Password'

     EXECUTE sp_executesql @sqlString,

     N'@UserName as varchar(10),  @Password as varchar(10)'

       @UserName,  @Password

END

GO