-------------------------------------------------

--插入值语法

insert  into table_name

(column1, column2, .. .)

values

(values1, values2, .. .)

-------------------------------------------------

--无条件INSERT ALL

insert  all

into sal_history values(EMPID,HIREDATE,SAL)

into mrg_history values(EMPID,MGR,SAL)

select employee_id EMPID,hire_date HIREDATE,salary SAL,manager_id MGR

from employee

where employee_id>200;

-------------------------------------------------

--有条件INSERT ALL

insert  all

--不论是否求值都为true

when SAL>10000then

into sal_history values(EMPID,HIREDATE,SAL)

when MGE>200then

into mrg_history values(EMPID,MGR,SAL)

select employee_id EMPID,hire_date HIREDATE,salary SAL,manager_id MGR

from employee

where employee_id>200;

-------------------------------------------------

--有条件的FIRST INSERT

insert  first

--如果这个第一个when子句的求值为true,后面的when字句不会执行

--直到第一个满足条件为止

when SAL>2500then

into special_sal values(DEPTID,SAL)

when HIREDATE like ('%00%') then

into hiredate_history_00 values(DEPTID,HIREDATE)

when hiredate like ('%99%') then

into hiredate_history_99 values(DEPTID,HIREDATE)

else

into hiredate_history values(DEPTID,HIREDATE)

select department_id DEPTID,SUM(salary) SAL,

MAX(hire_date) HIREDATE

from employees

GROUPBY department_id

--更新表名

update table_name

--更新的值

set column1 = values

--限制条件

where state = ''

--选择删除数据

delete  from customer

--删除的限制条件

where customer_id='adc232'

merge语句作用:

1.在一个SQL语句中对表同时执行插入和更新操作

2.可以从一个或多个数据源中选择行来更新或插入一个或多个表

--1.省略条件update子句

merge  into product p

using newproducts np

on(p.product_id = np.product_id)

--当上面条件匹配

when  matched  then

update

set p.product_name = np.product_name,

p.category = np.category;

--2.省略条件insert子句

merge  into product p

using newproducts np

on(p.product_id = np.product_id)

--当上面条件匹配

when  not  matched  then

insert

values (np.product_id,np.product_name,np_category);

--3.带条件的update语句

merge  into product p

using newproduct np

on (p.product_id = np.product_id)

when  matched  then

update  set p.product_name = np.product_name

where p.category = np.category;

--4.带条件的insert和update语句

merge into product p

using newproduct np

on (p.product_id = np.product_id)

--匹配到

when  matched  then

update

set p.product_name = np.product_name,

p.category = np.category

where p.category = 'DVD'

--匹配不到

when  not  matched  then

insert

values (np.product_id,np.product_name,np.category)

where np.category != 'BOOKS';

--5.无条件insert

merge  into product p

using newproduct np

on (1 = 0)

when  not  matched  then

insert

values(np.product_id,np.product_name,np.category)

where np.category = 'BOOKS';

--6.新加的delete功能

merge  into product p

using newproduct np

on (p.product_id = np.product_id)

when  matched  then

update

set p.product_name = np.product_name,p.category = np.category

delete  where (p.category = 'ELECARNCS')

where  not  matched  then

insert

values (np.product_id , np.product_name,np.category)

truncate table 语句

作用：快速，无日志记录删除表中的所有行

和delete比较优点

a.所有的事物日志空间较少

b.表中不会留下任何页