目地:更快地检索数据。
特点:读取数据速度快,但添加数据速度慢.。
语法:
create index idx_stu_email on stu (email) ; drop index idx_stu_email ; select index_name from user_indexs ; |
Oracle视图
特点:视图相当于子查询。
语法:
create view v$; select view_name from user_views ; desc v$_dept_avg_sal_info ; create view v$_stu as select id,name from stu; |
Oracle存储过程
语法:
1.创建不带参数的存储过程
create or replace procedure p as cursor c is select * from emp for update; begin for v_emp in c loop if(v_emp.deptno = 10) then update emp set sal = sal +10 where current of c; elsif (v_emp.deptno = 20) then update emp set sal = sal + 20 where current of c; else update emp set sal = sal + 50 where current of c; end if; end loop; commit; end; |
// 执行存储过程(两种方式)
· exec p; · begin p; end; |