Re: Comparing bug in 4.1.7

[Vlad Shalnev]

Bernard Clement wrote:
Hello Vlad,
The reason is: "If one or both arguments are NULL, the result of the 
comparison is NULL, except for the NULL-safe <=> equality comparison 
operator. 

Thereore, "or NULL" in your select statement will always returned NULL.
You can find all the rules for comparaison at URL: 
http://dev.mysql.com/doc/mysql/en/Comparison_Operators.html

Thanks for help but this is not my case. My case described in section "Logical 
Operators":

OR
||
Logical OR. Evaluates to 1 if any operand is non-zero, to NULL if any operand is 
NULL, otherwise 0 is returned.

mysql> SELECT 1 || 1;
        -> 1
mysql> SELECT 1 || 0;
        -> 1
mysql> SELECT 0 || 0;
        -> 0
mysql> SELECT 0 || NULL;
        -> NULL
mysql> SELECT 1 || NULL;
        -> 1
Any help appreciated.

Hi, All
It's happen after upgrade from 3.23.46.
Just look at this set of queries
mysql> select 1 or null;
+-----------+
| 1 or null |
+-----------+
|         1 | -> Ok
+-----------+
1 row in set (0.00 sec)
mysql> create table a ( a int not null );
Query OK, 0 rows affected (0.00 sec)
mysql> select min( a ) is null from a;
+------------------+
| min( a ) is null |
+------------------+
|                1 | -> Ok
+------------------+
1 row in set (0.00 sec)
mysql> select min( a ) is null or null from a;
+--------------------------+
| min( a ) is null or null |
+--------------------------+
|                     NULL | -> Why ???
+--------------------------+
1 row in set (0.00 sec)
It is very important for me to solve this problem. Thanks for any help
Info from mysqlbug script
Server version          4.1.7
Protocol version        10
Connection              Localhost via UNIX socket
UNIX socket             /tmp/.mysql.sock
Uptime:                 23 hours 43 min 34 sec
Threads: 2  Questions: 53  Slow queries: 0  Opens: 20  Flush tables: 1 
Open tables: 6  Queries per second avg: 0.001


C compiler:    2.95.3
C++ compiler:  2.95.3
>Environment:
        <machine, os, target, libraries (multiple lines)>
System: SunOS asv 5.8 Generic_108529-23 i86pc i386 i86pc
Architecture: i86pc
Some paths:  /usr/local/bin/perl /usr/ccs/bin/make /opt/sfw/bin/gmake
/opt/sfw/bin/gcc /usr/local/bin/cc
GCC: Reading specs from
/opt/sfw/lib/gcc-lib/i386-pc-solaris2.8/2.95.3/specs gcc version 2.95.3
20010315 (release)
Compilation info: CC='gcc'  CFLAGS=''  CXX='g++'  CXXFLAGS=''  LDFLAGS=''
ASFLAGS=''
LIBC:
-rw-r--r--   1 root     bin      1608268 Jul 30  2003 /lib/libc.a
lrwxrwxrwx   1 root     root          11 Mar  3  2004 /lib/libc.so ->
./libc.so.1 -rwxr-xr-x   1 root     bin       956112 Jul 30  2003
/lib/libc.so.1 -rw-r--r--   1 root     bin      1608268 Jul 30  2003
/usr/lib/libc.a lrwxrwxrwx   1 root     root          11 Mar  3  2004
/usr/lib/libc.so -> ./libc.so.1
-rwxr-xr-x   1 root     bin       956112 Jul 30  2003 /usr/lib/libc.so.1
Configure command: ./configure '--prefix=/usr/local/mysql-4.1.7'
'--exec-prefix=/usr/local/mysql-4.1.7'
'--libexecdir=/usr/local/mysql-4.1.7/bin' '--localstatedir=/main/MysqlDB'
'--enable-thread-safe-client'
'--with-unix-socket-path=/tmp/.mysql.sock' '--with-mysqld-user=mysql'
'--without-debug' '--without-bench' '--with-charset=koi8r'
Perl: This is perl, version 5.005_03 built for i86pc-solaris
--
---------------------------------------------------------------------------
----- Vlad A. Shalnev
E-mail: [EMAIL PROTECTED]
"Gravity can't be blamed
        for someone
                falling in love"
                        ( Albert Einstein )

--
--------------------------------------------------------------------------------
Vlad A. Shalnev
E-mail: [EMAIL PROTECTED]
"Gravity can't be blamed
        for someone
                falling in love"
                        ( Albert Einstein )
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