oracle知识点，踊跃共享，共享光荣 1,raise_application_error(-20005,''); 2,when no_data_found then 3 number(6,2)位数，保留小数位数 4 exec =call(包)函数 5create or replace trigger update_cascade after update of deptno on dept --update of deptno for each row declare -- local variables here begin update emp set deptno=:new.deptno where deptno =:old.deptno; end update_cascade; 6 create or replace trigger update_cascade after update of deptno on dept for each row declare -- local variables here begin update emp set deptno=:new.deptno wh ere deptno =:old.deptno; --new. / old. 的用法 end update_cascade; 7 嵌套表 nested table 元素个数没限制 create type emp_type as object( --as object name varchar2(10), salary number(6,2), hiredate date); create or replace type emp_array is table of emp_type; create table department( deptno number(2), dname varchar2(10), employee emp_array ) ) nested table employee store as employee; -- 存储表 ere deptno =:old.deptno; --new. / old. 的用法 end update_cascade; 7 嵌套表 nested table 元素个数没限制 create type emp_type as object( --as object name varchar2(10), salary number(6,2), hiredate date); create or replace type emp_array is table of emp_type; create table department( deptno number(2), dname varchar2(10), employee emp_array ) ) nested table employee store as employee; -- 存储表