One thing you have to watch out for is the fairly severe differences in the way SQL Server and MySQL implement the SQL syntax.
Here's a nice Comparison of Different SQL Implementations.
For example, take a look at the top-n section. In MySQL:
SELECT age
FROM person
ORDER BY age ASC
LIMIT 1 OFFSET 2
In SQL Server (T-SQL):
SELECT TOP 3 WITH TIES *
FROM person
ORDER BY age ASC