I just wanted to know whether writing update SQL query inside a for loop will effect the performance of the Database or not.Since everytime we iterate and update the record.Hence we are updating the Database this may increase the load on the Database hence the performance.
Well, yes, if you update a table then that is going to cause the database to do some work. And obviously that means the load on the database is increased, because now it has to do some work that it wasn't doing before. But that's trivially obvious and clearly not what you were looking for.
Unfortunately it's hard to tell what you are looking for instead. Based on your post there isn't much more that can be said.