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 Extra 1 SIMPLE t1 const UNIQ UNIQ 8 const 1 Warnings: Note 1003 select '00000001' AS `ID`,'004084688022709641610' 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; show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` varbinary(255) default NULL, `b` varchar(255) default NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 select length(a), length(b) from t1; length(a) length(b) 255 3 255 3 CHECK TABLE t1 FOR UPGRADE; Table Op Msg_type Msg_text test.t1 check error Table upgrade required. Please do "REPAIR TABLE `t1`" to fix it! REPAIR TABLE t1; Table Op Msg_type Msg_text test.t1 repair status OK show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` varbinary(255) default NULL, `b` varchar(255) default NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 select length(a), length(b) from t1; length(a) length(b) 3 3 3 3 insert into t1 values("ccc", "ddd"); select length(a), length(b) from t1; length(a) length(b) 3 3 3 3 3 3 select hex(a), hex(b) from t1; hex(a) hex(b) 616161 636363 626262 646464 636363 646464 select concat("'", a, "'"), concat("'", b, "'") from t1; concat("'", a, "'") concat("'", b, "'") 'aaa' 'ccc' 'bbb' 'ddd' 'ccc' 'ddd' drop table t1; create table t1(a varbinary(255)); insert into t1 values("aaa "); select length(a) from t1; length(a) 6 alter table t1 modify a varchar(255); select length(a) from t1; length(a) 6