关于oracle中"$"是什么意思？

Question

drop user &1 cascade;
create user &1 identified by &2;
grant connect,resource to &1;
connect &1/&2;
set define off;
怎么理解这段SQL语句？

Answer 1

&表示动态输入参数当执行时会弹出窗口，提示你输入比如执行drop user &1 cascade;会提示输入1参数值执行create user &1 identified by &2;时，回依次提示输入参数1和参数2的值