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

1. 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;
2. 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
3. NEXTTWO:insert,updae,delete,select pass
4. 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.