Salary AS lesson sample

Question

Using the + 500 AS salary. Is salary a new column? or does this result in a change to the existing column?
Basically, could someone screw up the database? And is there a history function where you could track changes and possible errors?
Thank you...

Answer 1

The AS keyword is used when you want to provide a custom column name at the time when your result is displayed. It is not permanent.
In SQL you can make changes permanent and save them, you can undo the changes and some similar operations can be performed using Transaction Control Language (TCL).

Answer 2

Very clear. Thank you!