Is there a difference between these two queries?

Question

Well, pretty simple question I think, but I can\'t find a satisfying answer. Is there a difference between these two queries?

SELECT * FROM table WHERE colum         


        

Answer 1

No, there's not a single difference.

See more MySQL Syntax here.

Answer 2

The role of parenthesis will be usefull when there is one more condition with AND operator. otherwise no difference in execution plan except syntax.

Answer 3

No. its the same. As long as there are only two conditions braces doesn't have much significance.

Answer 4

Further to my comment above, the manual explains:

Some of the optimizations performed by MySQL follow:

• Removal of unnecessary parentheses:

     ((a AND b) AND c OR (((a AND b) AND (c AND d))))
  -> (a AND b AND c) OR (a AND b AND c AND d)

So no, there is no difference whatsoever.

Answer 5

Right now there is NO difference in your queries.

There would be difference if there would be AND condition as addition in your query.

e.g

SELECT * FROM table WHERE id=1 AND column1 = 'x' OR column2 = 'x'

and

SELECT * FROM table WHERE id=1 AND (column1 = 'x' OR column2 = 'x')

Note

SELECT * FROM table WHERE id=1 AND column1 = 'x' OR column2 = 'x'

would be equivalent to

SELECT * FROM table WHERE (id=1 AND column1 = 'x') OR column2 = 'x'

Hope you get the difference.