Bug #69208 A typo in sql_yacc.yy leads to possibility of creation valid nonsense queries
Submitted: 13 May 2013 5:22 Modified: 20 May 2013 7:55
Reporter: Ivan Kurnosov Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: Parser Severity:S3 (Non-critical)
Version:any OS:Any
Assigned to: CPU Architecture:Any

[13 May 2013 5:22] Ivan Kurnosov 
Description:
On the expressions syntax documentation page (and in the sql_yacc.yy) the `predicate` definition for `BETWEEN` operator contains a typo. It should be

    bit_expr [NOT] BETWEEN bit_expr AND bit_expr

instead of

    bit_expr [NOT] BETWEEN bit_expr AND predicate

How to repeat:
Run

    select 1 between 1 and 5 between 5 and 10;

Suggested fix:
| bit_expr BETWEEN_SYM bit_expr AND_SYM predicate

perhaps needs to be replaced with

| bit_expr BETWEEN_SYM bit_expr AND_SYM bit_expr

The same for `not BETWEEN_SYM`
[13 May 2013 6:07] Valeriy Kravchuk 
Even more complex expressions still work:

mysql>  select (1 between 1 and 2) between (1 between 1 and 5) and (5 between 5
and 10);
+--------------------------------------------------------------------------+
| (1 between 1 and 2) between (1 between 1 and 5) and (5 between 5 and 10) |
+--------------------------------------------------------------------------+
|                                                                        1 |
+--------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql>  select (1 between 2 and 3) between (1 between 1 and 5) and (5 between 5
and 10);
+--------------------------------------------------------------------------+
| (1 between 2 and 3) between (1 between 1 and 5) and (5 between 5 and 10) |
+--------------------------------------------------------------------------+
|                                                                        0 |
+--------------------------------------------------------------------------+
1 row in set (0.00 sec)

I wonder why do you consider them nonsense and (based on the above) I am not sure suggested change will help in any way.
[13 May 2013 6:57] Ivan Kurnosov 
@Valeriy Kravchuk

oh right, didn't notice that.

Indeed the proposed change wouldn't change the behaviour but will make a code and a grammar on the documentation page more clear and obvious (at least it won't .

PS: now I'm finding it less nonsense, I agree it may be used in some weird and unreadable queries.
[20 May 2013 7:55] MySQL Verification Team 
Thank you for the report.