Oracle 中游标的使用

declare cursor my_cur is select empno,deptno from emp;
employee_id emp.empno%type;
dept_id emp.deptno%type;
begin
open my_cur;
fetch my_cur into employee_id,dept_id;
while my_cur%found loop
dbms_output.put_line(employee_id||' shit '||dept_id);
fetch my_cur into employee_id,dept_id;
end loop;
end;

使用行变量来获取游标信息

declare cursor mycur is select * from emp;
var_emp emp%rowtype;
begin
open mycur;
fetch mycur into var_emp;
while mycur%found loop
dbms_output.put_line(var_emp.ename||':'||+to_char(var_emp.hiredate,'yyyy-MM-dd'));
fetch mycur into var_emp;
end loop;
end;

隐式游标

declare var_count integer;
begin
update A set ename='B';
var_count:=sql%rowcount;
dbms_output.put_line(to_char(var_count));
end;

动态游标

定义

declare type emp_cur_type is ref cursor return emp%rowtype;

new_emp_cur_type emp_cur_type;

open new_emp_cur_type for select * from emp;