Select top N where N is a variable
A lot of kids don't know this so it's worth writing down.
Let's imagine you start with a query that shows the top 50, such as:
Select TOP 50 * from Leaderboard order by Score desc
Later, you want to make '50' a variable, so you try:
DECLARE @limit int = 50
Select TOP @limit * from Leaderboard order by Score desc
And you're met with an error, to wit:
Msg 102, Level 15, State 1, Line 2
Incorrect syntax near '@limit'.
So you give up, and decide it's impossible.
What you don't realise is just how close to victory you were!
Put parentheses around the @limit and you're done!
DECLARE @limit int = 50
Select TOP(@limit) * from Leaderboard order by Score desc
Presto!
(In other news, Access DB won't let you use 'Select top 0 * from TableName
' ...pesky Access)