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drop table if exists t1,t2;
create table t1 (
c_id int(11) not null default '0',
org_id int(11) default null,
unique key contacts$c_id (c_id),
key contacts$org_id (org_id)
) engine=innodb;
insert into t1 values
(2,null),(120,null),(141,null),(218,7), (128,1),
(151,2),(234,2),(236,2),(243,2),(255,2),(259,2),(232,3),(235,3),(238,3),
(246,3),(253,3),(269,3),(285,3),(291,3),(293,3),(131,4),(230,4),(231,4);
create table t2 (
slai_id int(11) not null default '0',
owner_tbl int(11) default null,
owner_id int(11) default null,
sla_id int(11) default null,
inc_web int(11) default null,
inc_email int(11) default null,
inc_chat int(11) default null,
inc_csr int(11) default null,
inc_total int(11) default null,
time_billed int(11) default null,
activedate timestamp null default null,
expiredate timestamp null default null,
state int(11) default null,
sla_set int(11) default null,
unique key t2$slai_id (slai_id),
key t2$owner_id (owner_id),
key t2$sla_id (sla_id)
) engine=innodb;
insert into t2(slai_id, owner_tbl, owner_id, sla_id) values
(1,3,1,1), (3,3,10,2), (4,3,3,6), (5,3,2,5), (6,3,8,3), (7,3,9,7),
(8,3,6,8), (9,3,4,9), (10,3,5,10), (11,3,11,11), (12,3,7,12);
flush tables;
select si.slai_id
from t1 c join t2 si on
((si.owner_tbl = 3 and si.owner_id = c.org_id) or
( si.owner_tbl = 2 and si.owner_id = c.c_id))
where
c.c_id = 218 and expiredate is null;
slai_id
12
select * from t1 where org_id is null;
c_id org_id
2 NULL
120 NULL
141 NULL
select si.slai_id
from t1 c join t2 si on
((si.owner_tbl = 3 and si.owner_id = c.org_id) or
( si.owner_tbl = 2 and si.owner_id = c.c_id))
where
c.c_id = 218 and expiredate is null;
slai_id
12
drop table t1, t2;
create table t1m (a int) engine=myisam;
create table t1i (a int) engine=innodb;
create table t2m (a int) engine=myisam;
create table t2i (a int) engine=innodb;
insert into t2m values (5);
insert into t2i values (5);
select min(a) from t1m;
min(a)
NULL
select min(7) from t1m;
min(7)
NULL
select min(7) from DUAL;
min(7)
NULL
explain select min(7) from t2m join t1m;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
select min(7) from t2m join t1m;
min(7)
NULL
select max(a) from t1m;
max(a)
NULL
select max(7) from t1m;
max(7)
NULL
select max(7) from DUAL;
max(7)
NULL
explain select max(7) from t2m join t1m;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
select max(7) from t2m join t1m;
max(7)
NULL
select 1, min(a) from t1m where a=99;
1 min(a)
1 NULL
select 1, min(a) from t1m where 1=99;
1 min(a)
1 NULL
select 1, min(1) from t1m where a=99;
1 min(1)
1 NULL
select 1, min(1) from t1m where 1=99;
1 min(1)
1 NULL
select 1, max(a) from t1m where a=99;
1 max(a)
1 NULL
select 1, max(a) from t1m where 1=99;
1 max(a)
1 NULL
select 1, max(1) from t1m where a=99;
1 max(1)
1 NULL
select 1, max(1) from t1m where 1=99;
1 max(1)
1 NULL
select min(a) from t1i;
min(a)
NULL
select min(7) from t1i;
min(7)
NULL
select min(7) from DUAL;
min(7)
NULL
explain select min(7) from t2i join t1i;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2i ALL NULL NULL NULL NULL 1
1 SIMPLE t1i ALL NULL NULL NULL NULL 1
select min(7) from t2i join t1i;
min(7)
NULL
select max(a) from t1i;
max(a)
NULL
select max(7) from t1i;
max(7)
NULL
select max(7) from DUAL;
max(7)
NULL
explain select max(7) from t2i join t1i;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2i ALL NULL NULL NULL NULL 1
1 SIMPLE t1i ALL NULL NULL NULL NULL 1
select max(7) from t2i join t1i;
max(7)
NULL
select 1, min(a) from t1i where a=99;
1 min(a)
1 NULL
select 1, min(a) from t1i where 1=99;
1 min(a)
1 NULL
select 1, min(1) from t1i where a=99;
1 min(1)
1 NULL
select 1, min(1) from t1i where 1=99;
1 min(1)
1 NULL
select 1, max(a) from t1i where a=99;
1 max(a)
1 NULL
select 1, max(a) from t1i where 1=99;
1 max(a)
1 NULL
select 1, max(1) from t1i where a=99;
1 max(1)
1 NULL
select 1, max(1) from t1i where 1=99;
1 max(1)
1 NULL
explain select count(*), min(7), max(7) from t1m, t1i;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1m system NULL NULL NULL NULL 0 const row not found
1 SIMPLE t1i ALL NULL NULL NULL NULL 1
select count(*), min(7), max(7) from t1m, t1i;
count(*) min(7) max(7)
0 NULL NULL
explain select count(*), min(7), max(7) from t1m, t2i;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1m system NULL NULL NULL NULL 0 const row not found
1 SIMPLE t2i ALL NULL NULL NULL NULL 1
select count(*), min(7), max(7) from t1m, t2i;
count(*) min(7) max(7)
0 NULL NULL
explain select count(*), min(7), max(7) from t2m, t1i;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2m system NULL NULL NULL NULL 1
1 SIMPLE t1i ALL NULL NULL NULL NULL 1
select count(*), min(7), max(7) from t2m, t1i;
count(*) min(7) max(7)
0 NULL NULL
drop table t1m, t1i, t2m, t2i;
create table t1 (
a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(64) default ' '
);
insert into t1 (a1, a2, b, c, d) values
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
('a','a','b','e112','xy1'),('a','a','b','f112','xy2'),('a','a','b','g112','xy3'),('a','a','b','h112','xy4'),
('a','b','a','i121','xy1'),('a','b','a','j121','xy2'),('a','b','a','k121','xy3'),('a','b','a','l121','xy4'),
('a','b','b','m122','xy1'),('a','b','b','n122','xy2'),('a','b','b','o122','xy3'),('a','b','b','p122','xy4'),
('b','a','a','a211','xy1'),('b','a','a','b211','xy2'),('b','a','a','c211','xy3'),('b','a','a','d211','xy4'),
('b','a','b','e212','xy1'),('b','a','b','f212','xy2'),('b','a','b','g212','xy3'),('b','a','b','h212','xy4'),
('b','b','a','i221','xy1'),('b','b','a','j221','xy2'),('b','b','a','k221','xy3'),('b','b','a','l221','xy4'),
('b','b','b','m222','xy1'),('b','b','b','n222','xy2'),('b','b','b','o222','xy3'),('b','b','b','p222','xy4'),
('c','a','a','a311','xy1'),('c','a','a','b311','xy2'),('c','a','a','c311','xy3'),('c','a','a','d311','xy4'),
('c','a','b','e312','xy1'),('c','a','b','f312','xy2'),('c','a','b','g312','xy3'),('c','a','b','h312','xy4'),
('c','b','a','i321','xy1'),('c','b','a','j321','xy2'),('c','b','a','k321','xy3'),('c','b','a','l321','xy4'),
('c','b','b','m322','xy1'),('c','b','b','n322','xy2'),('c','b','b','o322','xy3'),('c','b','b','p322','xy4'),
('d','a','a','a411','xy1'),('d','a','a','b411','xy2'),('d','a','a','c411','xy3'),('d','a','a','d411','xy4'),
('d','a','b','e412','xy1'),('d','a','b','f412','xy2'),('d','a','b','g412','xy3'),('d','a','b','h412','xy4'),
('d','b','a','i421','xy1'),('d','b','a','j421','xy2'),('d','b','a','k421','xy3'),('d','b','a','l421','xy4'),
('d','b','b','m422','xy1'),('d','b','b','n422','xy2'),('d','b','b','o422','xy3'),('d','b','b','p422','xy4'),
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
('a','a','b','e112','xy1'),('a','a','b','f112','xy2'),('a','a','b','g112','xy3'),('a','a','b','h112','xy4'),
('a','b','a','i121','xy1'),('a','b','a','j121','xy2'),('a','b','a','k121','xy3'),('a','b','a','l121','xy4'),
('a','b','b','m122','xy1'),('a','b','b','n122','xy2'),('a','b','b','o122','xy3'),('a','b','b','p122','xy4'),
('b','a','a','a211','xy1'),('b','a','a','b211','xy2'),('b','a','a','c211','xy3'),('b','a','a','d211','xy4'),
('b','a','b','e212','xy1'),('b','a','b','f212','xy2'),('b','a','b','g212','xy3'),('b','a','b','h212','xy4'),
('b','b','a','i221','xy1'),('b','b','a','j221','xy2'),('b','b','a','k221','xy3'),('b','b','a','l221','xy4'),
('b','b','b','m222','xy1'),('b','b','b','n222','xy2'),('b','b','b','o222','xy3'),('b','b','b','p222','xy4'),
('c','a','a','a311','xy1'),('c','a','a','b311','xy2'),('c','a','a','c311','xy3'),('c','a','a','d311','xy4'),
('c','a','b','e312','xy1'),('c','a','b','f312','xy2'),('c','a','b','g312','xy3'),('c','a','b','h312','xy4'),
('c','b','a','i321','xy1'),('c','b','a','j321','xy2'),('c','b','a','k321','xy3'),('c','b','a','l321','xy4'),
('c','b','b','m322','xy1'),('c','b','b','n322','xy2'),('c','b','b','o322','xy3'),('c','b','b','p322','xy4'),
('d','a','a','a411','xy1'),('d','a','a','b411','xy2'),('d','a','a','c411','xy3'),('d','a','a','d411','xy4'),
('d','a','b','e412','xy1'),('d','a','b','f412','xy2'),('d','a','b','g412','xy3'),('d','a','b','h412','xy4'),
('d','b','a','i421','xy1'),('d','b','a','j421','xy2'),('d','b','a','k421','xy3'),('d','b','a','l421','xy4'),
('d','b','b','m422','xy1'),('d','b','b','n422','xy2'),('d','b','b','o422','xy3'),('d','b','b','p422','xy4');
create table t4 (
pk_col int auto_increment primary key, a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(64) default ' '
) engine=innodb;
insert into t4 (a1, a2, b, c, d, dummy) select * from t1;
create index idx12672_0 on t4 (a1);
create index idx12672_1 on t4 (a1,a2,b,c);
create index idx12672_2 on t4 (a1,a2,b);
analyze table t1;
Table Op Msg_type Msg_text
test.t1 analyze status OK
select distinct a1 from t4 where pk_col not in (1,2,3,4);
a1
a
b
c
d
drop table t1,t4;
create table t1 (
a varchar(30), b varchar(30), primary key(a), key(b)
) engine=innodb;
select distinct a from t1;
a
drop table t1;
create table t1(a int, key(a)) engine=innodb;
insert into t1 values(1);
select a, count(a) from t1 group by a with rollup;
a count(a)
1 1
NULL 1
drop table t1;
create table t1 (f1 int, f2 char(1), primary key(f1,f2)) engine=innodb;
insert into t1 values ( 1,"e"),(2,"a"),( 3,"c"),(4,"d");
alter table t1 drop primary key, add primary key (f2, f1);
explain select distinct f1 a, f1 b from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL PRIMARY 5 NULL 4 Using index; Using temporary
explain select distinct f1, f2 from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL PRIMARY 5 NULL 3 Using index for group-by; Using temporary
drop table t1;
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