In real time applications there might be situation where you need update details of one table using details of another or update two or tables using one statement. Below is Example of how you can do that in SQL Server
Update t1 Set t1.col1 = t2.col1 from Table t1 inner join Table t2 on t1.col = t2.col where Condtn
Below is MYSql Example
Update Table t1 inner join Table t2 on t1.col = t2.col Set t1.col1 = t2.col1 where Condtn