drop table if exists t1; select 0x41,0x41+0,0x41 | 0x7fffffffffffffff | 0,0xffffffffffffffff | 0 ; 0x41 0x41+0 0x41 | 0x7fffffffffffffff | 0 0xffffffffffffffff | 0 A 65 9223372036854775807 18446744073709551615 select 0x31+1,concat(0x31)+1,-0xf; 0x31+1 concat(0x31)+1 -0xf 50 2 -15 select x'31',X'ffff'+0; x'31' X'ffff'+0 1 65535 create table t1 (ID int(8) unsigned zerofill not null auto_increment,UNIQ bigint(21) unsigned zerofill not null,primary key (ID),unique (UNIQ) ); insert into t1 set UNIQ=0x38afba1d73e6a18a; insert into t1 set UNIQ=123; explain extended select * from t1 where UNIQ=0x38afba1d73e6a18a; id select_type table type possible_keys key key_len ref rows filtered Extra 1 SIMPLE t1 const UNIQ UNIQ 8 const 1 100.00 Warnings: Note 1003 select `test`.`t1`.`ID` AS `ID`,`test`.`t1`.`UNIQ` AS `UNIQ` from `test`.`t1` where 1 drop table t1; select x'hello'; ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'x'hello'' at line 1 select 0xfg; ERROR 42S22: Unknown column '0xfg' in 'field list' create table t1 select 1 as x, 2 as xx; select x,xx from t1; x xx 1 2 drop table t1;