oracle数据库sql语句08 PL SQL程序结构 循环 游标

PL/SQL程序结构 

set serveroutput on

declare

 season int :=3;

 info varchar2(50);

begin

 season := &season;

 case season

 when 1 then

  info := season||'季度包含1,2,3月份';

 when 2 then

  info := season||'季度包含4,5,6月份';

 when 3 then

  info := season||'季度包含7,8,9月份';

 when 4 then

  info := season||'季度包含10,11,12月份';

 else

  info := '季度不合法';

 end case;

 dbms_output.put_line(info);

end;

/

循环结构

--for

declare

 sum_i int:=0;

 i int := 0;

begin

 for i in 1..100 loop

  sum_i:=sum_i+i;

 end loop;

 dbms_output.put_line(sum_i);

end;

/

--while

declare

 sum_i int:=0;

 i int := 0;

begin

 while i<=99 loop

 i:=i+1;

 sum_i:=sum_i+i;

 end loop;

 dbms_output.put_line(sum_i);

end;

/

--loop

declare

 sum_i int:=0;

 i int := 0;

begin

 loop

 i:=i+1;

 sum_i:=sum_i+i;

 exit when i >99;

 end loop;

 dbms_output.put_line(sum_i);

end;

/

--显式游标

--游标 while

declare

 cursor cur_emp is select * from emp where deptno=30;

 a emp%rowtype;

begin

 open cur_emp;

 fetch cur_emp into a;

 while cur_emp%found loop
dbms_output.put_line(a.ename);
fetch cur_emp into a;

 end loop;

 close cur_emp;

end;

/

--游标 loop

declare

 cursor cur_emp is select * from emp where deptno=30;

 a emp%rowtype;

begin

 open cur_emp;

 loop

 fetch cur_emp into a;

 exit when cur_emp%notfound;

 dbms_output.put_line(a.ename);

 end loop;

 close cur_emp;

end;

/

--游标 for 自动打开、读取、关闭 游标

declare

 cursor cur_emp is select * from emp where deptno=30;

begin

 for i in cur_emp loop
dbms_output.put_line(i.ename);

 end loop;

end;

/

--隐式游标

begin
update emp set sal=sal+100 where job='SALESMAN';
if sql%found then
dbms_output.put_line(sql%rowcount||'有员工跟新');
else
dbms_output.put_line('无员工跟新');
end if;

end;

/

declare
aa emp%rowtype;

begin
select * into aa from emp where job='SALESMAN';
if sql%found then
dbms_output.put_line(sql%rowcount||'有员工跟新');
else
dbms_output.put_line('无员工跟新');
end if;

end;

/

begin
for i in (select * from emp where deptno=30) loop
dbms_output.put_line(i.empno||'  '||i.ename);
end loop;

end;

/