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DROP TABLE IF EXISTS t1;
SET NAMES cp932;
CREATE TABLE t1 (c1 INTEGER COMMENT ' ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±', c12 INTEGER, c13 DATETIME, c14 CHAR(10), PRIMARY KEY(c1), INDEX(c12,c13)) COMMENT='ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR';
SELECT table_comment,char_length(table_comment) FROM information_schema.tables WHERE table_name='t1';
table_comment char_length(table_comment)
ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR 60
SELECT column_comment,char_length(column_comment) FROM information_schema.columns WHERE table_name='t1';
column_comment char_length(column_comment)
¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
0
0
0
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`c1` int(11) NOT NULL DEFAULT '0' COMMENT ' ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c12` int(11) DEFAULT NULL,
`c13` datetime DEFAULT NULL,
`c14` char(10) DEFAULT NULL,
PRIMARY KEY (`c1`),
KEY `c12` (`c12`,`c13`)
) ENGINE=ENGINE DEFAULT CHARSET=latin1 COMMENT='ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR'
ALTER TABLE t1 ADD COLUMN c2 INTEGER COMMENT 'A¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±';
ALTER TABLE t1 ADD COLUMN c3 INTEGER COMMENT ' C€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±';
ALTER TABLE t1 ADD COLUMN c4 INTEGER COMMENT ' ¢EŠš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±';
ALTER TABLE t1 ADD COLUMN c5 INTEGER COMMENT ' ¢€Gš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±';
SELECT table_comment,char_length(table_comment) FROM information_schema.tables WHERE table_name='t1';
table_comment char_length(table_comment)
ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR 60
SELECT column_comment,char_length(column_comment) FROM information_schema.columns WHERE table_name='t1';
column_comment char_length(column_comment)
¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
0
0
0
A¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
C€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
¢EŠš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
¢€Gš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`c1` int(11) NOT NULL DEFAULT '0' COMMENT ' ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c12` int(11) DEFAULT NULL,
`c13` datetime DEFAULT NULL,
`c14` char(10) DEFAULT NULL,
`c2` int(11) DEFAULT NULL COMMENT 'A¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c3` int(11) DEFAULT NULL COMMENT ' C€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c4` int(11) DEFAULT NULL COMMENT ' ¢EŠš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c5` int(11) DEFAULT NULL COMMENT ' ¢€Gš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
PRIMARY KEY (`c1`),
KEY `c12` (`c12`,`c13`)
) ENGINE=ENGINE DEFAULT CHARSET=latin1 COMMENT='ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR'
ALTER TABLE t1 MODIFY COLUMN c3 CHAR(10);
SELECT table_comment,char_length(table_comment) FROM information_schema.tables WHERE table_name='t1';
table_comment char_length(table_comment)
ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR 60
SELECT column_comment,char_length(column_comment) FROM information_schema.columns WHERE table_name='t1';
column_comment char_length(column_comment)
¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
0
0
0
A¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
0
¢EŠš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
¢€Gš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`c1` int(11) NOT NULL DEFAULT '0' COMMENT ' ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c12` int(11) DEFAULT NULL,
`c13` datetime DEFAULT NULL,
`c14` char(10) DEFAULT NULL,
`c2` int(11) DEFAULT NULL COMMENT 'A¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c3` char(10) DEFAULT NULL,
`c4` int(11) DEFAULT NULL COMMENT ' ¢EŠš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c5` int(11) DEFAULT NULL COMMENT ' ¢€Gš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
PRIMARY KEY (`c1`),
KEY `c12` (`c12`,`c13`)
) ENGINE=ENGINE DEFAULT CHARSET=latin1 COMMENT='ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR'
ALTER TABLE t1 CHANGE COLUMN c4 c4_1 INTEGER COMMENT '³µ·¹»œ¿ÂÄÆ';
SELECT table_comment,char_length(table_comment) FROM information_schema.tables WHERE table_name='t1';
table_comment char_length(table_comment)
ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR 60
SELECT column_comment,char_length(column_comment) FROM information_schema.columns WHERE table_name='t1';
column_comment char_length(column_comment)
¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
0
0
0
A¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
0
³µ·¹»œ¿ÂÄÆ 10
¢€Gš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`c1` int(11) NOT NULL DEFAULT '0' COMMENT ' ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c12` int(11) DEFAULT NULL,
`c13` datetime DEFAULT NULL,
`c14` char(10) DEFAULT NULL,
`c2` int(11) DEFAULT NULL COMMENT 'A¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c3` char(10) DEFAULT NULL,
`c4_1` int(11) DEFAULT NULL COMMENT '³µ·¹»œ¿ÂÄÆ',
`c5` int(11) DEFAULT NULL COMMENT ' ¢€Gš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
PRIMARY KEY (`c1`),
KEY `c12` (`c12`,`c13`)
) ENGINE=ENGINE DEFAULT CHARSET=latin1 COMMENT='ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR'
ALTER TABLE t1 DROP COLUMN c2;
SELECT table_comment,char_length(table_comment) FROM information_schema.tables WHERE table_name='t1';
table_comment char_length(table_comment)
ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR 60
SELECT column_comment,char_length(column_comment) FROM information_schema.columns WHERE table_name='t1';
column_comment char_length(column_comment)
¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
0
0
0
0
³µ·¹»œ¿ÂÄÆ 10
¢€Gš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± 60
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`c1` int(11) NOT NULL DEFAULT '0' COMMENT ' ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
`c12` int(11) DEFAULT NULL,
`c13` datetime DEFAULT NULL,
`c14` char(10) DEFAULT NULL,
`c3` char(10) DEFAULT NULL,
`c4_1` int(11) DEFAULT NULL COMMENT '³µ·¹»œ¿ÂÄÆ',
`c5` int(11) DEFAULT NULL COMMENT ' ¢€Gš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯± ¢€Šš©«¯±',
PRIMARY KEY (`c1`),
KEY `c12` (`c12`,`c13`)
) ENGINE=ENGINE DEFAULT CHARSET=latin1 COMMENT='ACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPRACEGIJLNPR'
DROP TABLE t1;
|