select format(1.5555,0),format(123.5555,1),format(1234.5555,2),format(12345.55555,3),format(123456.5555,4),format(1234567.5555,5),format("12345.2399",2);
format(1.5555,0)	format(123.5555,1)	format(1234.5555,2)	format(12345.55555,3)	format(123456.5555,4)	format(1234567.5555,5)	format("12345.2399",2)
2	123.6	1,234.56	12,345.556	123,456.5555	1,234,567.55550	12,345.24
select inet_ntoa(inet_aton("255.255.255.255.255.255.255.255"));
inet_ntoa(inet_aton("255.255.255.255.255.255.255.255"))
NULL
select inet_aton("255.255.255.255.255"),inet_aton("255.255.1.255"),inet_aton("0.1.255");
inet_aton("255.255.255.255.255")	inet_aton("255.255.1.255")	inet_aton("0.1.255")
1099511627775	4294902271	65791
select inet_ntoa(1099511627775),inet_ntoa(4294902271),inet_ntoa(511);
inet_ntoa(1099511627775)	inet_ntoa(4294902271)	inet_ntoa(511)
NULL	255.255.1.255	0.0.1.255
select hex(inet_aton('127'));
hex(inet_aton('127'))
7F
select hex(inet_aton('127.1'));
hex(inet_aton('127.1'))
7F000001
select hex(inet_aton('127.1.1'));
hex(inet_aton('127.1.1'))
7F010001
select length(uuid()), charset(uuid()), length(unhex(replace(uuid(),_utf8'-',_utf8'')));
length(uuid())	charset(uuid())	length(unhex(replace(uuid(),_utf8'-',_utf8'')))
36	utf8	16
select length(format('nan', 2)) > 0;
length(format('nan', 2)) > 0
1
Warnings:
Warning	1292	Truncated incorrect DOUBLE value: 'nan'
select concat("$",format(2500,2));
concat("$",format(2500,2))
$2,500.00
create table t1 ( a timestamp );
insert into t1 values ( '2004-01-06 12:34' );
select a from t1 where left(a+0,6) in ( left(20040106,6) );
a
2004-01-06 12:34:00
select a from t1 where left(a+0,6) = ( left(20040106,6) );
a
2004-01-06 12:34:00
select a from t1 where right(a+0,6) in ( right(20040106123400,6) );
a
2004-01-06 12:34:00
select a from t1 where right(a+0,6) = ( right(20040106123400,6) );
a
2004-01-06 12:34:00
select a from t1 where mid(a+0,6,3) in ( mid(20040106123400,6,3) );
a
2004-01-06 12:34:00
select a from t1 where mid(a+0,6,3) = ( mid(20040106123400,6,3) );
a
2004-01-06 12:34:00
drop table t1;
create table t1 as select uuid(), length(uuid());
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `uuid()` varchar(36) character set utf8 NOT NULL default '',
  `length(uuid())` int(10) NOT NULL default '0'
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 (a timestamp default '2005-05-05 01:01:01',
b timestamp default '2005-05-05 01:01:01');
insert into t1 set a = now();
select sleep(3);
sleep(3)
0
update t1 set b = now();
select timediff(b, a) >= '00:00:03' from t1;
timediff(b, a) >= '00:00:03'
1
drop table t1;
set global query_cache_size=1355776;
create table t1 (a int);
insert into t1 values (1),(1),(1);
create table t2 (a datetime default null, b datetime default null);
insert into t2 set a = now();
select a from t1 where sleep(1);
a
update t2 set b = now() where b is null;
insert into t2 set a = now();
select a from t1 where sleep(a);
a
update t2 set b = now() where b is null;
insert into t2 set a = now();
select a from t1 where sleep(1);
a
update t2 set b = now() where b is null;
select timediff(b, a) >= '00:00:03' from t2;
timediff(b, a) >= '00:00:03'
1
1
1
drop table t2;
drop table t1;
set global query_cache_size=default;