Ok, here’s a brain-twister. Not only can you assign values to a column in an UPDATE statement using variables, but you can assign values to variables as well. It’s really not as complicated as it may sound, but there are a few trapdoors to avoid.
accumulation
Calculating business days and holidays
A common scenario you may have encountered is the need to calculate the first business day after a given date. There are quite a few ugly ways to solve this, including cursors, but there are also some pretty neat ways to approach the problem, and as a bonus, you’ll learn about recursion and the new LEAD(), LAG() functions and accumulation in T-SQL.
sqlsunday.com 