calculate(sum(金额),all(城市)) -- 所有城市总合计distinctcount(城市)calculate(sum(金额),all(城市)) / distinctcount(城市)
pf09045141
2020-06-24
（a as number, b as number,c as number)=> ..... 理解了 逻辑和内容 竟然在格式上耽搁不少时间，原来最简单基础的 往往也是最容易被忽略的 且最容易出错的地方 。
pf09045141
2020-06-22
create table employee( empno int primary key auto_increment, ename varchar(10) unique, job varchar(10) not null, mgr int, hiredate date, sal float default 0, comm float, deptno int, foreign
pf09045141
2020-06-18
-- 限制查询结果数量 -- 查询基本工资最高的前5位员工 select * from emp order by sal desc limit 5; select * from emp order by sal desc limit 0,5; -- 查询基本工资第6到10名的员工 select * from emp order by sal desc limit 5,5;
pf09045141
2020-06-16
load data infile "C:/ProgramData/MySQL/MySQL Server 8.0/Uploads/employee.csv" into table emp fields terminated by ',' ignore 1 lines;
pf09045141
2020-06-15
