oracle常用的SQL语句

 1.标准Insert --单表单行插入

insert into dep (dep_id,dep_name) values(1,'技术部');

 2. 无条件 Insert all --多表多行插入

insert all
INTO sal_history(emp_id,hire_date,salary) values (empid,hiredate,sal)
INTO mgr_history(emp_id,manager_id,salary) values (empid,hiredate,sal)
SELECT employee_id empid,hire_date hiredate,salary sal,manager_id mgr
FROM employees
WHERE employee_id>200;

 3. 有条件的Insert

       备注:

      a.当使用ALL关键字时,oracle会从上至下判断每一个条件,当条件满足时就执行后面的into语句

         在上面的例子中,如果ID=6 那么将会在z_test1中插入一条记录,同时也在z_test2中插入一条记录

      b.当使用FIRST关键字时,oracle会从上至下判断每一个条件,当遇到第一个满足时就执行后面的into语句,

         同时中断判断的条件判断,在上面的例子中,如果ID=6,仅仅会在z_test1中插入一条数据

Insert All
when id>5 then into z_test1(id, name) values(id,name)
when id<>2 then into z_test2(id) values(id)
else into z_test3 values(name)
select id,name from z_test;

4. 旋转Insert (pivoting insert)

insert all
into sales_info values(employee_id,week_id,sales_mon)
into sales_info values(employee_id,week_id,sales_tue)
into sales_info values(employee_id,week_id,sales_wed)
into sales_info values(employee_id,week_id,sales_thur)
into sales_info values(employee_id,week_id,sales_fri)
select employee_id,week_id,sales_mon,sales_tue,
sales_wed,sales_thur,sales_fri
from sales_source_data;

 5.常用查询保留小数位数的函数

select round(100/3,4) from dual;
select trunc(100/3,4) from dual;