前言sql作为一门古老的语言,学习起来性价比超高!几十年都不用更新!查询语句select 字段1,字段2 from 表 where 字段1='xxxx'去重查询select distinct 字段 from 表where符号select * from 表 where 字段 符号 ...
create sequence seq_test star with 1 increment by 1 nocache nomaxvalue; create table xxx(id); create or replace trigger "trixxx" before insert on xxx refere...