What is this db command?

[loveitandhateit]

MySQL query:
DELETE FROM students WHERE id = '57' LIMIT 1

First of all, is this query correct? (structure, syntax)
Second, what on earth is this LIMIT thing, and what does it do?

[laserlight]

I'm not familiar with the use of LIMIT outside of SELECT queries, so I'm not sure if it is legal, but generally
LIMIT offset, num

Will act on num number of rows after skipping offset number of rows.
If the offset is not specified, then it becomes
LIMIT num

By that reasoning, the given query will delete the first row in the students table that has id=57

[cahva]

That LIMIT is perfecly legal in DELETE queries. It can prevent accidents if someone puts error in delete query and by mistake deletes all of the table's rows 🙂

[laserlight]

maybe not prevent accidents, more like an exercise in damage limitation :p