Oracle学习笔记 - 第002天

Oracle

序列

create table tb_goods
(
gid number(8,0),
gname varchar2(50) not null,
gprice number(8,2) not null,
gdesc varchar2(500)
);
alter table tb_goods add constraint
pk_goods_gid primary key (gid);

create sequence seq_goods
start with 10000000
increment by 10
cache 100;

drop sequence seq_test;
create sequence seq_test
start with 1
increment by 2
minvalue 1
maxvalue 10
cycle nocache;

select seq_goods.nextval from dual;
select seq_goods.currval from dual;

insert into tb_goods values (seq_goods.nextval, '农夫山泉500ml', 1.5, null);

同义词

select * from scott.emp;
create public synonym emp for scott.emp;
select * from emp;

视图

create view vw_emp as
select empno, ename, deptno from emp;

select * from vw_emp;

create or replace;

grant create view to scott;
revoke create view from scott;

索引

create index idx_goods_name on tb_goods (gname) cluster; 

自然连接(通过外键关系进行连接)

select ename, dname from emp t1
natural join dept t2;

交叉连接(笛卡尔积)

select ename, dname from emp t1
cross join dept t2;

函数

create or replace function fn_jc(n number)
return number is 
  result number := 1;
  i number := 1;
begin
  for i in 1..n loop
    result := result * i;
  end loop;
  return result;
end fn_jc;

select fn_jc(5) from dual;

create or replace function fn_addGoodsData
return number is
  i number := 1;
begin
  for i in 1..10000 loop
    insert into tb_goods values 
    (seq_goods.nextval, '农夫山泉'||i, 1.5, null);
  end loop;
end fn_addGoodsData;

存储过程

create or replace procedure sp_addGoodsData is
  i number := 1;
begin
  for i in 1..10000 loop
    insert into tb_goods values 
    (seq_goods.nextval, '农夫山泉'||i, 1.5, null);
  end loop;
  commit;
end sp_addGoodsData;

begin
  sp_addGoodsData();
end;

create or replace procedure sp_getAvgSalByDeptNo(
          dno emp.deptno%type,
          avgSal out emp.sal%type) is
begin
  select avg(sal) into avgSal from emp where deptno=dno;
end sp_getAvgSalByDeptNo;

常用命令

sqlplus /nolog
shutdown immediate

desc dba_sys_privs
select * from user_sys_privs

set linesize 180
show linesize
show pagesize
select table_name from tabs;

show recyclebin;
flashback table emp to before drop;
drop table emp purge;
purge recyclebin;

grant create view to scott;
revoke create view from scott;

create user kygo identified by 123456 password expire;
grant create session to kygo;
grant unlimited tablespace to kygo;
grant create table to kygo;

create role normal_user;
grant create session to normal_user;
grant unlimited tablespace to normal_user;
grant create table to normal_user;
create user kygo indetified by 123456 password expire;
grant normal_user to kygo with admin option;

连接oracle数据库

例子1:连接数据库并用已经写好的sql语句执行

        try {
            Class.forName("oracle.jdbc.driver.OracleDriver");
            try (Connection conn = DriverManager.getConnection(
                    "jdbc:oracle:thin:@localhost:1521:orcl", "scott", "tiger")) {
                CallableStatement cs = conn.prepareCall(
                        "{call sp_getAvgSalByDeptNo(?, ?)}");
                cs.setInt(1, 10);
                cs.registerOutParameter(2, Types.DOUBLE);
                cs.execute();
                System.out.println(cs.getDouble(2));
            } catch (SQLException e) {
                e.printStackTrace();
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }