ORACLE的基本文法集錦—-簡單卻是最基本的

-- 表
create table test (names varchar2(12),
                   dates date,
                   num   int,
                   dou   double);

-- 視圖
create or replace view vi_test as
select * from test;

 

-- 同義字
create or replace synonym aa
for dbusrcard001.aa;

 

-- 預存程序
create or replace produce dd(v_id in employee.empoy_id%type)
as
begin
  
end
dd;

 

-- 函數
create or replace function ee(v_id in employee%rowtype) return varchar(15)
is
var_test varchar2(15);
begin
  return var_test;
exception when others then
  
end

 

-- 三種觸發器的定義
create or replace trigger ff
alter delete
on test
for each row
declare
begin
   delete from test;
   if sql%rowcount < 0 or sql%rowcount is null then
      rais_replaction_err(-20004,"錯誤")
   end if
end

create or replace trigger gg
alter insert
on test
for each row
declare
begin
   if :old.names = :new.names then
      raise_replaction_err(-2003,"編碼重複");
   end if
end

create or replace trigger hh
for update
on test
for each row
declare
begin
  if updating then
     if :old.names <> :new.names then
 reaise_replaction_err(-2002,"關鍵字不能修改")
     end if
  end if
end

-- 定義遊標
declare
   cursor aa is
      select names,num from test;
begin
   for bb in aa
   loop
        if bb.names = "ORACLE" then
       
        end if
   end loop;
  
end

 

-- 速度最佳化，前一語句不後一語句的速度快幾十倍
select names,dates
from test,b
where test.names = b.names(+) and
      b.names is null and
      b.dates > date(''2003-01-01'',''yyyy-mm-dd'')

 
select names,dates
from test
where names not in ( select names
                       from b
                      where dates > to_date(''2003-01-01'',''yyyy-mm-dd''))
                      

-- 尋找重複記錄
select names,num
from test
where rowid != (select max(rowid)
                 from test b
                where b.names = test.names and
                      b.num = test.num)

-- 尋找表TEST中時間最新的前10條記錄
select * from (select * from test order by dates desc) where rownum < 11

 

-- 序號的產生
create sequence row_id
minvalue 1
maxvalue 9999999999999999999999
start with 1
increment by 1

insert into test values(row_id.nextval,....)