mysql对表惯用操作
时间:2021-07-01 10:21:17
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mysql对表常用操作 NEXTONE :create create table testtable( id int(10) not null auto_increment primary key comment '', name varchar(20) not null character set utf8 comment '', age? int null comment '', gender char(2) coment '', gmt_created da
mysql对表常用操作
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NEXTONE :create
create table testtable(
id int(10) not null auto_increment primary key comment '',
name varchar(20) not null character set utf8 comment '',
age? int null comment '',
gender char(2) coment '',
gmt_created datetime not null comment ''
)engine=innoDB default charset=utf8;
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Set the increment sequence: auto_increment
Set the primary key: primary key
Label: comment.
Set the field is not empty: not null
Set the field be empty: null
Format: character set utf8
Char fixed length variable length, varchar
Time type: datetime
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NEXTTWO:insert,updae,delete,select pass
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NEXTTHREE:alert:
1.delete column
?alter talbe table drop column
2.alert rename
?alter table table rename new_table
3.alter drop primary key
?alter table table drop primary key
4.alter add primary key
?alter table sj_resource_charges add constraint pk_sj_resource_charges primary key (resid,resfromid)
5.add column
?alter table table add column_name type not null comment ''
6.change column type
?alter table table change column_name new_column_name type not null comment ''
7.alter index_name
?alter table table add colunm index_name(index_column_name)
8.alter drop index emp_name
?alter table table drop index index_column_name
NEXTFOUR:
drop
Structure of the drop statement will delete tables are dependent constraints (constrain), trigger (trigger), index (index) depends on the table;
The stored procedure / function will be retained, but to the invalid state.