select pass_key into :key from pass_tbl ; /*암호화키를 구한다.*/
insert into user_tbl (pw,name) values (encrypt(:pw,:key),encrypt(:name,:key));/*입력시 암호와*/
select decrypt_char(pw,:key) pw,decrypt_char(nm,:key) nm from user_tbl;    /*조회시 암호를 해독*/