oracle基础学习(2)

oracle循环的几种写法:

declare

x number :=5;

begin

--x:=0;

loop

x:=x+1;

/*

if (x=10) then 

exit; 

end if;

*/

exit when x=10;

dbms_output.put_line('x='||x);

end loop;

dbms_output.put_line('outer');

end;

/

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

declare

x number :=5;

begin

while x<10 loop

x:=x+1;

dbms_output.put_line('x='||x);

end loop;

dbms_output.put_line('outer');

end;

/



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

begin

for x in 2..10 loop

	dbms_output.put_line('x='||x);

end loop;

end;

/

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

declare

x number:=5;

begin

<
 
   
    
  >	--标记

x:=x+1;

dbms_output.put_line('x='||x);

if x<10 then 

goto label1;

end if;

end;

/

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



异常处理

Exception

when .. then

...

常见系统异常

DUP_VAL_ON_INDEX

NO_DATA_FOUND

TOO_MANY_ROWS

VALUE_ERROR

ZERO_DIVIDE



e.g.:



declare

va varchar2(20);

begin

select A into va from abc where F_NVAR='abc';

dbms_output.put_line(va);

exception

when NO_DATA_FOUND THEN

DBMS_OUTPUT.PUT_LINE('未找到数据');

end;

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



declare

va varchar2(20);

vi integer;

begin

select A into va from abc where F_NVAR='中国人民万';

dbms_output.put_line(va);

vi:=1/0;

exception

when NO_DATA_FOUND THEN

DBMS_OUTPUT.PUT_LINE('未找到数据');

when OTHERS THEN

DBMS_OUTPUT.PUT_LINE('其它问题');

end;

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



declare

va varchar2(20);

vi integer;

e exception;

begin

select A into va from abc where F_NVAR='中国人民万';

dbms_output.put_line(va);

--vi:=1/0;

raise e;

exception

when NO_DATA_FOUND THEN

DBMS_OUTPUT.PUT_LINE('未找到数据');

when e THEN

DBMS_OUTPUT.PUT_LINE('发生问题A');

when OTHERS THEN

DBMS_OUTPUT.PUT_LINE('其它问题');

end;

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



复合变量:记录

TYPE type_name IS RECORD(

Variable_name datatype,

Variable_name datatype,

...

);



-----------



declare 

myrec abc%rowtype;

begin

select * into myrec from abc where a='aaa';

dbms_output.put_line(myrec.a||myrec.b||myrec.c);

end;



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

ROW_NUMBER() 函数 与 ROWNUM伪列

select row_number() over (order by a) sa,a,b,c,f_nvar from abc

select * from abc where rownum<10





declare 

myrec abc%rowtype;

begin

select * into myrec from abc where a='AAA1111123' and ROWNUM<2;

dbms_output.put_line(myrec.a||myrec.b||myrec.c||myrec.f_nvar);

end;

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

一个简单的存储过程:

create or replace procedure proc_show_abc_by_a

(

pa varchar2

)

as

fa varchar2(20);

begin

select a into fa from spark.abc where a=pa;

dbms_output.put_line(fa);

end;

/



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

同义词

 create or replace public synonym myabc for spark.abc;

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

序列

create sequence myseq

start with 1

increment by 1

order

nocycle;