摘要: 1.查询单个字段 select last_name from employees; 2.查询多个字段 select last_name,salary,email from employees; 3.查询所有字段 select * from employees; 4.查询常量值 select 100; 阅读全文
posted @ 2020-05-29 22:06 peterWXM 阅读(126) 评论(0) 推荐(0) 编辑