Oracle练习：

创建表格：

create table customer_info(id int primary key not null,first_name varchar(20),last_name varchar(20),sex char(2),age char(3));

创建序列：参考资料 http://zhidao.baidu.com/question/82436743.html

create sequence id_seq minvalue 1 maxvalue 10000000000000000 start with 1 increment by 1 cache 20 cycle;

修改表列名：

alter table table_name rename column column_name to xxx；

表中新增列：

alter table customer_info add(telephone varchar(30));

建立表的外键关系：

alter table purchase_item add foreign key(purchaser_id) references purchase_people(purchaser_id);

修改表名：

alter table table_nameA rename to table_nameB;

修改列数据类型：

alter table PURCHASE_ITEM modify STATUS_ID varchar2(20);

从表中删除列：

alter table tablename drop columname;

alter table purchase_item modify purchaser_id number(10);

oracle中往timestamp类型的列添加系统时间值：

insert into table(a)

values to_char(sysdate,‘yyyy-mm-dd hh24-mi-ss‘)

查询外键：

SELECT * FROM user_constraints;

多列定义为一个主键：

alter table purchase_item_detail ADD CONSTRAINT pk_purchase_item_detail PRIMARY KEY(purchase_item_detail_id,purchase_item_id);

给单独表格授权：

grant DELETE, INSERT, REFERENCES, SELECT, UPDATE on user_constraints to lisu;

约束所在的表有：

select * from user_constraints where table_name in (‘STOCK_IN_ITEM‘,‘STOCK_IN_ITEM_DETAIL‘);

delete from all_constraints where constraint_name in (‘SYS_C0011883‘,‘SYS_C0011886‘);

select * from dba_constraints;

select * from all_constraints where owner =‘LISU‘;

date类型插入值：

insert into user_login (user_login_id,operate_date) values (‘admin‘,sysdate);