AMrss的博客

MySQL(1) 数据库的增删改查# 如果存在删除drop database if exists kh69;# 创建数据库create database kh69;# 进库use kh69;# 创建省份表create table province( provinceId int(2) auto_increment primary key, provinceName varcha...

MySQL(2) 数据库的增删改查#子查询select (select stuName from student where stuId=s.stuId) stuName, (select subjectName from subject where subjectId=s.subjectId) subjectName, scorefrom score s;#查询江苏南京的学院信...

MySQL(3) 数据库的增删改查#4、查询参加[平均成绩最低科目]考试的学员成绩前三名的学员所在的地址信息select J.subjectId,J.subjectName,S.stuId,stuName,provinceName ,cityName ,countyNamefrom subject Jinner join score Ron J.subjectId=R.subj...

MySQL(4) 数据库的增删改查#创建学员成绩视图create view v_scoreas select scoreId, stuName, score, if(isIn,'正常','缺考') isIn, if(level,'正常',concat('补考',(level-1))) from score S inner join student U on...

MySQL(5) 数据库函数#自定义函数DELIMITER //create function func_name( param_name data_type(n), ...)returns rtn_typefunc_body//DELIMITER;#例子DELIMITER //create function addsun(a int,b int)returns in...