数据库学习第四天：区间/多条件/模糊/通配符查询

--统计英语成绩个数（统计时null不参与计算)
select COUNT(tsenglish) from tb_score
-- 查询英语成绩大于60的学生id
select tsid from tb_score where tsenglish > 60
--查询性别为男的年纪在20-30岁之间的学生
select * from tb_score where tsage>=20 and tsage<=30 and tsgender = 1
select * from tb_score where tagender = 1 and tsage between 20 and 30
--查询学会生ID为1或2或3的学生
select * from tb_student where tclassid = 1 or tclassid = 2 or tclassid = 3
select * from tb_student where tclassid in(1,2,3)
select * from tb_customers where country in ('UK','USA')
--查询名字'李'开头的
select * from tb_student where tsname like '李%'
--查询以'李'开头的并且名字只有两个字
select * from tb_student where tsname like '李_'
--查询以'李'开头的并且名字只有三个字
select * from tb_student where tsname like '李%' and Len(tsname) = 3
--查询姓张的名字间含有字母的且名字只有三个字的人
select * from tb_student where tsname like '张[a-z]'
--姓名中包含'李’字的
select * from tb_student where tsname like '%李%'
--查询学生中含张的名字长度不限的
select * from tb_student where tsname like '张[%]%'
--姓名中不包含数字
select * from tb_student where tsname like '张[^0-9]'