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drop table if exists t1,t2;
create table t1 (a int not null primary key, b int not null,c int not null, key(b,c));
insert into t1 values (1,2,2),(2,2,3),(3,2,4),(4,2,4);
check table t1 fast;
Table Op Msg_type Msg_text
test.t1 check status Table is already up to date
check table t1 fast;
Table Op Msg_type Msg_text
test.t1 check status Table is already up to date
check table t1 changed;
Table Op Msg_type Msg_text
test.t1 check status OK
insert into t1 values (5,5,5);
check table t1 changed;
Table Op Msg_type Msg_text
test.t1 check status OK
check table t1 medium;
Table Op Msg_type Msg_text
test.t1 check status OK
check table t1 extended;
Table Op Msg_type Msg_text
test.t1 check status OK
show index 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 A 5 NULL NULL BTREE
t1 1 b 1 b A 1 NULL NULL BTREE
t1 1 b 2 c A 5 NULL NULL BTREE
insert into t1 values (5,5,5);
ERROR 23000: Duplicate entry '5' for key 1
optimize table t1;
Table Op Msg_type Msg_text
test.t1 optimize status OK
optimize table t1;
Table Op Msg_type Msg_text
test.t1 optimize status Table is already up to date
drop table t1;
show variables like "wait_timeout%";
Variable_name Value
wait_timeout 28800
show variables like "WAIT_timeout%";
Variable_name Value
wait_timeout 28800
show variables like "this_doesn't_exists%";
Variable_name Value
show table status from test like "this_doesn't_exists%";
Name Type Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment Create_time Update_time Check_time Collation Checksum Create_options Comment
show databases;
Database
mysql
test
show databases like "test%";
Database (test%)
test
create table t1 (f1 int not null, f2 int not null, f3 int not null, f4 int not null, primary key(f1,f2,f3,f4));
insert into t1 values (1,1,1,0),(1,1,2,0),(1,1,3,0),(1,2,1,0),(1,2,2,0),(1,2,3,0),(1,3,1,0),(1,3,2,0),(1,3,3,0),(1,1,1,1),(1,1,2,1),(1,1,3,1),(1,2,1,1),(1,2,2,1),(1,2,3,1),(1,3,1,1),(1,3,2,1),(1,3,3,1);
analyze table t1;
Table Op Msg_type Msg_text
test.t1 analyze status OK
show index 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 f1 A 1 NULL NULL BTREE
t1 0 PRIMARY 2 f2 A 3 NULL NULL BTREE
t1 0 PRIMARY 3 f3 A 9 NULL NULL BTREE
t1 0 PRIMARY 4 f4 A 18 NULL NULL BTREE
repair table t1;
Table Op Msg_type Msg_text
test.t1 repair status OK
show index 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 f1 A 1 NULL NULL BTREE
t1 0 PRIMARY 2 f2 A 3 NULL NULL BTREE
t1 0 PRIMARY 3 f3 A 9 NULL NULL BTREE
t1 0 PRIMARY 4 f4 A 18 NULL NULL BTREE
drop table t1;
create temporary table t1 (a int not null);
show create table t1;
Table Create Table
t1 CREATE TEMPORARY TABLE `t1` (
`a` int(11) NOT NULL default '0'
) TYPE=MyISAM DEFAULT CHARSET=latin1
alter table t1 rename t2;
show create table t2;
Table Create Table
t2 CREATE TEMPORARY TABLE `t2` (
`a` int(11) NOT NULL default '0'
) TYPE=MyISAM DEFAULT CHARSET=latin1
drop table t2;
create table t1 (
test_set set( 'val1', 'val2', 'val3' ) not null default '',
name char(20) default 'O''Brien' comment 'O''Brien as default',
c int not null comment 'int column'
) comment = 'it\'s a table' ;
show create table t1 ;
Table Create Table
t1 CREATE TABLE `t1` (
`test_set` set('val1','val2','val3') NOT NULL default '',
`name` char(20) default 'O''Brien' COMMENT 'O''Brien as default',
`c` int(11) NOT NULL default '0' COMMENT 'int column'
) TYPE=MyISAM DEFAULT CHARSET=latin1 COMMENT='it''s a table'
show full columns from t1;
Field Type Collation Null Key Default Extra Privileges Comment
test_set set('val1','val2','val3') latin1_swedish_ci select,insert,update,references
name char(20) latin1_swedish_ci YES O'Brien select,insert,update,references O'Brien as default
c int(11) NULL 0 select,insert,update,references int column
drop table t1;
create table t1 (a int not null, unique aa (a));
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) NOT NULL default '0',
UNIQUE KEY `aa` (`a`)
) TYPE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 (a int not null, primary key (a));
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) NOT NULL default '0',
PRIMARY KEY (`a`)
) TYPE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
flush tables;
show open tables;
Database Table In_use Name_locked
create table t1(n int);
insert into t1 values (1);
show open tables;
Database Table In_use Name_locked
test t1 0 0
drop table t1;
create table t1 (a int not null, b VARCHAR(10), INDEX (b) ) AVG_ROW_LENGTH=10 CHECKSUM=1 COMMENT="test" TYPE=MYISAM MIN_ROWS=10 MAX_ROWS=100 PACK_KEYS=1 DELAY_KEY_WRITE=1 ROW_FORMAT=fixed;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) NOT NULL default '0',
`b` char(10) default NULL,
KEY `b` (`b`)
) TYPE=MyISAM DEFAULT CHARSET=latin1 MIN_ROWS=10 MAX_ROWS=100 AVG_ROW_LENGTH=10 PACK_KEYS=1 CHECKSUM=1 DELAY_KEY_WRITE=1 ROW_FORMAT=FIXED COMMENT='test'
alter table t1 MAX_ROWS=200 ROW_FORMAT=dynamic PACK_KEYS=0;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) NOT NULL default '0',
`b` varchar(10) default NULL,
KEY `b` (`b`)
) TYPE=MyISAM DEFAULT CHARSET=latin1 MIN_ROWS=10 MAX_ROWS=200 AVG_ROW_LENGTH=10 PACK_KEYS=0 CHECKSUM=1 DELAY_KEY_WRITE=1 ROW_FORMAT=DYNAMIC COMMENT='test'
ALTER TABLE t1 AVG_ROW_LENGTH=0 CHECKSUM=0 COMMENT="" MIN_ROWS=0 MAX_ROWS=0 PACK_KEYS=DEFAULT DELAY_KEY_WRITE=0 ROW_FORMAT=default;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) NOT NULL default '0',
`b` varchar(10) default NULL,
KEY `b` (`b`)
) TYPE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 (a decimal(9,2), b decimal (9,0), e double(9,2), f double(5,0), h float(3,2), i float(3,0));
show columns from t1;
Field Type Null Key Default Extra
a decimal(9,2) YES NULL
b decimal(9,0) YES NULL
e double(9,2) YES NULL
f double(5,0) YES NULL
h float(3,2) YES NULL
i float(3,0) YES NULL
show full columns from t1;
Field Type Collation Null Key Default Extra Privileges Comment
a decimal(9,2) NULL YES NULL select,insert,update,references
b decimal(9,0) NULL YES NULL select,insert,update,references
e double(9,2) NULL YES NULL select,insert,update,references
f double(5,0) NULL YES NULL select,insert,update,references
h float(3,2) NULL YES NULL select,insert,update,references
i float(3,0) NULL YES NULL select,insert,update,references
drop table t1;
create table t1 (
type_bool bool not null,
type_tiny tinyint not null auto_increment primary key,
type_short smallint(3),
type_mediumint mediumint,
type_bigint bigint,
type_decimal decimal(5,2),
type_numeric numeric(5,2),
empty_char char(0),
type_char char(2),
type_varchar varchar(10),
type_timestamp timestamp not null,
type_date date not null,
type_time time not null,
type_datetime datetime not null,
type_year year,
type_enum enum ('red', 'green', 'blue'),
type_set enum ('red', 'green', 'blue'),
type_tinyblob tinyblob,
type_blob blob,
type_medium_blob mediumblob,
type_long_blob longblob,
index(type_short)
) AVG_ROW_LENGTH=10 CHECKSUM=1 COMMENT="test" TYPE=MYISAM MIN_ROWS=10 MAX_ROWS=100 PACK_KEYS=1 DELAY_KEY_WRITE=1 ROW_FORMAT=fixed CHARSET=latin1;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`type_bool` tinyint(1) NOT NULL default '0',
`type_tiny` tinyint(4) NOT NULL auto_increment,
`type_short` smallint(3) default NULL,
`type_mediumint` mediumint(9) default NULL,
`type_bigint` bigint(20) default NULL,
`type_decimal` decimal(5,2) default NULL,
`type_numeric` decimal(5,2) default NULL,
`empty_char` char(0) default NULL,
`type_char` char(2) default NULL,
`type_varchar` varchar(10) default NULL,
`type_timestamp` timestamp NOT NULL,
`type_date` date NOT NULL default '0000-00-00',
`type_time` time NOT NULL default '00:00:00',
`type_datetime` datetime NOT NULL default '0000-00-00 00:00:00',
`type_year` year(4) default NULL,
`type_enum` enum('red','green','blue') default NULL,
`type_set` enum('red','green','blue') default NULL,
`type_tinyblob` tinyblob,
`type_blob` blob,
`type_medium_blob` mediumblob,
`type_long_blob` longblob,
PRIMARY KEY (`type_tiny`),
KEY `type_short` (`type_short`)
) TYPE=MyISAM DEFAULT CHARSET=latin1 MIN_ROWS=10 MAX_ROWS=100 AVG_ROW_LENGTH=10 PACK_KEYS=1 CHECKSUM=1 DELAY_KEY_WRITE=1 ROW_FORMAT=FIXED COMMENT='test'
insert into t1 (type_timestamp) values ("2003-02-07 10:00:01");
select * from t1;
type_bool type_tiny type_short type_mediumint type_bigint type_decimal type_numeric empty_char type_char type_varchar type_timestamp type_date type_time type_datetime type_year type_enum type_set type_tinyblob type_blob type_medium_blob type_long_blob
0 1 NULL NULL NULL NULL NULL NULL NULL NULL 2003-02-07 10:00:01 0000-00-00 00:00:00 0000-00-00 00:00:00 NULL NULL NULL NULL NULL NULL NULL
drop table t1;
create table t1 (a int not null);
create table t2 select max(a) from t1;
show columns from t2;
Field Type Null Key Default Extra
max(a) bigint(20) YES NULL
drop table t1,t2;
create table t1 (c decimal, d double, f float, r real);
show columns from t1;
Field Type Null Key Default Extra
c decimal(10,0) YES NULL
d double YES NULL
f float YES NULL
r double YES NULL
drop table t1;
create table t1 (c decimal(3,3), d double(3,3), f float(3,3));
show columns from t1;
Field Type Null Key Default Extra
c decimal(4,3) YES NULL
d double(4,3) YES NULL
f float(4,3) YES NULL
drop table t1;
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