heap.result
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:8k
- drop table if exists t1;
- create table t1 (a int not null,b int not null, primary key (a)) engine=heap comment="testing heaps" avg_row_length=100 min_rows=1 max_rows=100;
- insert into t1 values(1,1),(2,2),(3,3),(4,4);
- delete from t1 where a=1 or a=0;
- show keys from t1;
- Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
- t1 0 PRIMARY 1 a NULL 3 NULL NULL HASH
- select * from t1;
- a b
- 2 2
- 3 3
- 4 4
- select * from t1 where a=4;
- a b
- 4 4
- update t1 set b=5 where a=4;
- update t1 set b=b+1 where a>=3;
- replace t1 values (3,3);
- select * from t1;
- a b
- 2 2
- 3 3
- 4 6
- alter table t1 add c int not null, add key (c,a);
- drop table t1;
- create table t1 (a int not null,b int not null, primary key (a)) engine=memory comment="testing heaps";
- insert into t1 values(1,1),(2,2),(3,3),(4,4);
- delete from t1 where a > 0;
- select * from t1;
- a b
- drop table t1;
- create table t1 (a int not null,b int not null, primary key (a)) engine=heap comment="testing heaps";
- insert into t1 values(1,1),(2,2),(3,3),(4,4);
- alter table t1 modify a int not null auto_increment, engine=myisam, comment="new myisam table";
- select * from t1;
- a b
- 1 1
- 2 2
- 3 3
- 4 4
- drop table t1;
- create table t1 (a int not null) engine=heap;
- insert into t1 values (869751),(736494),(226312),(802616);
- select * from t1 where a > 736494;
- a
- 869751
- 802616
- alter table t1 add unique uniq_id(a);
- select * from t1 where a > 736494;
- a
- 869751
- 802616
- select * from t1 where a = 736494;
- a
- 736494
- select * from t1 where a=869751 or a=736494;
- a
- 736494
- 869751
- select * from t1 where a in (869751,736494,226312,802616);
- a
- 226312
- 736494
- 802616
- 869751
- alter table t1 engine=myisam;
- explain select * from t1 where a in (869751,736494,226312,802616);
- id select_type table type possible_keys key key_len ref rows Extra
- 1 SIMPLE t1 range uniq_id uniq_id 4 NULL 4 Using where; Using index
- drop table t1;
- create table t1 (x int not null, y int not null, key x (x), unique y (y))
- engine=heap;
- insert into t1 values (1,1),(2,2),(1,3),(2,4),(2,5),(2,6);
- select * from t1 where x=1;
- x y
- 1 3
- 1 1
- select * from t1,t1 as t2 where t1.x=t2.y;
- x y x y
- 1 1 1 1
- 2 2 2 2
- 1 3 1 1
- 2 4 2 2
- 2 5 2 2
- 2 6 2 2
- explain select * from t1,t1 as t2 where t1.x=t2.y;
- id select_type table type possible_keys key key_len ref rows Extra
- 1 SIMPLE t1 ALL x NULL NULL NULL 6
- 1 SIMPLE t2 eq_ref y y 4 test.t1.x 1
- drop table t1;
- create table t1 (a int) engine=heap;
- insert into t1 values(1);
- select max(a) from t1;
- max(a)
- 1
- drop table t1;
- CREATE TABLE t1 ( a int not null default 0, b int not null default 0, key(a), key(b) ) ENGINE=HEAP;
- insert into t1 values(1,1),(1,2),(2,3),(1,3),(1,4),(1,5),(1,6);
- select * from t1 where a=1;
- a b
- 1 6
- 1 5
- 1 4
- 1 3
- 1 2
- 1 1
- insert into t1 values(1,1),(1,2),(2,3),(1,3),(1,4),(1,5),(1,6);
- select * from t1 where a=1;
- a b
- 1 6
- 1 5
- 1 4
- 1 3
- 1 2
- 1 1
- 1 6
- 1 5
- 1 4
- 1 3
- 1 2
- 1 1
- drop table t1;
- create table t1 (id int unsigned not null, primary key (id)) engine=HEAP;
- insert into t1 values(1);
- select max(id) from t1;
- max(id)
- 1
- insert into t1 values(2);
- select max(id) from t1;
- max(id)
- 2
- replace into t1 values(1);
- drop table t1;
- create table t1 (n int) engine=heap;
- drop table t1;
- create table t1 (n int) engine=heap;
- drop table if exists t1;
- CREATE table t1(f1 int not null,f2 char(20) not
- null,index(f2)) engine=heap;
- INSERT into t1 set f1=12,f2="bill";
- INSERT into t1 set f1=13,f2="bill";
- INSERT into t1 set f1=14,f2="bill";
- INSERT into t1 set f1=15,f2="bill";
- INSERT into t1 set f1=16,f2="ted";
- INSERT into t1 set f1=12,f2="ted";
- INSERT into t1 set f1=12,f2="ted";
- INSERT into t1 set f1=12,f2="ted";
- INSERT into t1 set f1=12,f2="ted";
- delete from t1 where f2="bill";
- select * from t1;
- f1 f2
- 16 ted
- 12 ted
- 12 ted
- 12 ted
- 12 ted
- drop table t1;
- create table t1 (btn char(10) not null, key(btn)) engine=heap;
- insert into t1 values ("hello"),("hello"),("hello"),("hello"),("hello"),("a"),("b"),("c"),("d"),("e"),("f"),("g"),("h"),("i");
- explain select * from t1 where btn like "q%";
- id select_type table type possible_keys key key_len ref rows Extra
- 1 SIMPLE t1 ALL btn NULL NULL NULL 14 Using where
- select * from t1 where btn like "q%";
- btn
- alter table t1 add column new_col char(1) not null, add key (btn,new_col), drop key btn;
- update t1 set new_col=left(btn,1);
- explain select * from t1 where btn="a";
- id select_type table type possible_keys key key_len ref rows Extra
- 1 SIMPLE t1 ALL btn NULL NULL NULL 11 Using where
- explain select * from t1 where btn="a" and new_col="a";
- id select_type table type possible_keys key key_len ref rows Extra
- 1 SIMPLE t1 ref btn btn 11 const,const 2 Using where
- drop table t1;
- CREATE TABLE t1 (
- a int default NULL,
- b int default NULL,
- KEY a (a),
- UNIQUE b (b)
- ) engine=heap;
- INSERT INTO t1 VALUES (NULL,99),(99,NULL),(1,1),(2,2),(1,3);
- SELECT * FROM t1 WHERE a=NULL;
- a b
- explain SELECT * FROM t1 WHERE a IS NULL;
- id select_type table type possible_keys key key_len ref rows Extra
- 1 SIMPLE t1 ref a a 5 const 1 Using where
- SELECT * FROM t1 WHERE a<=>NULL;
- a b
- NULL 99
- SELECT * FROM t1 WHERE b=NULL;
- a b
- explain SELECT * FROM t1 WHERE b IS NULL;
- id select_type table type possible_keys key key_len ref rows Extra
- 1 SIMPLE t1 ref b b 5 const 1 Using where
- SELECT * FROM t1 WHERE b<=>NULL;
- a b
- 99 NULL
- INSERT INTO t1 VALUES (1,3);
- ERROR 23000: Duplicate entry '3' for key 1
- DROP TABLE t1;
- CREATE TABLE t1 (
- a int default NULL,
- key a (a)
- ) ENGINE=HEAP;
- INSERT INTO t1 VALUES (10), (10), (10);
- EXPLAIN SELECT * FROM t1 WHERE a=10;
- id select_type table type possible_keys key key_len ref rows Extra
- 1 SIMPLE t1 ref a a 5 const 3 Using where
- SELECT * FROM t1 WHERE a=10;
- a
- 10
- 10
- 10
- DROP TABLE t1;
- CREATE TABLE t1 (a int not null, primary key(a)) engine=heap;
- INSERT into t1 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11);
- DELETE from t1 where a < 100;
- SELECT * from t1;
- a
- DROP TABLE t1;
- CREATE TABLE `job_titles` (
- `job_title_id` int(6) unsigned NOT NULL default '0',
- `job_title` char(18) NOT NULL default '',
- PRIMARY KEY (`job_title_id`),
- UNIQUE KEY `job_title_id` (`job_title_id`,`job_title`)
- ) ENGINE=HEAP;
- SELECT MAX(job_title_id) FROM job_titles;
- MAX(job_title_id)
- NULL
- DROP TABLE job_titles;
- CREATE TABLE t1 (a INT NOT NULL, B INT, KEY(B)) ENGINE=HEAP;
- INSERT INTO t1 VALUES(1,1), (1,NULL);
- SELECT * FROM t1 WHERE B is not null;
- a B
- 1 1
- DROP TABLE t1;
- CREATE TABLE t1 (pseudo char(35) PRIMARY KEY, date int(10) unsigned NOT NULL) ENGINE=HEAP;
- INSERT INTO t1 VALUES ('massecot',1101106491),('altec',1101106492),('stitch+',1101106304),('Seb Corgan',1101106305),('beerfilou',1101106263),('flaker',1101106529),('joce8',5),('M4vrick',1101106418),('gabay008',1101106525),('Vamp irX',1101106291),('ZoomZip',1101106546),('rip666',1101106502),('CBP ',1101106397),('guezpard',1101106496);
- DELETE FROM t1 WHERE date<1101106546;
- SELECT * FROM t1;
- pseudo date
- ZoomZip 1101106546
- DROP TABLE t1;
- create table t1(a char(2)) engine=memory;
- insert into t1 values (NULL), (NULL);
- delete from t1 where a is null;
- insert into t1 values ('2'), ('3');
- select * from t1;
- a
- 3
- 2
- drop table t1;
- create table t1 (a bigint unsigned auto_increment primary key, b int,
- key (b, a)) engine=heap;
- insert t1 (b) values (1);
- insert t1 (b) values (1);
- insert t1 (b) values (1);
- insert t1 (b) values (1);
- insert t1 (b) values (1);
- insert t1 (b) values (1);
- insert t1 (b) values (1);
- insert t1 (b) values (1);
- select * from t1;
- a b
- 1 1
- 2 1
- 3 1
- 4 1
- 5 1
- 6 1
- 7 1
- 8 1
- drop table t1;
- create table t1 (a int not null, b int not null auto_increment,
- primary key(a, b), key(b)) engine=heap;
- insert t1 (a) values (1);
- insert t1 (a) values (1);
- insert t1 (a) values (1);
- insert t1 (a) values (1);
- insert t1 (a) values (1);
- insert t1 (a) values (1);
- insert t1 (a) values (1);
- insert t1 (a) values (1);
- select * from t1;
- a b
- 1 1
- 1 2
- 1 3
- 1 4
- 1 5
- 1 6
- 1 7
- 1 8
- drop table t1;
- create table t1 (c char(255), primary key(c(90)));
- insert into t1 values ("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz");
- insert into t1 values ("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz");
- ERROR 23000: Duplicate entry 'abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijkl' for key 1
- drop table t1;