GROUP BY department_id:按department_id进行分组。 HAVING COUNT(*) > 1:过滤出员工数量大于1的部门。 执行上述查询后,你将得到一个结果集,其中包含每个员工数量大于1的部门及其对应的员工数量。 确保在执行查询之前,你已经正确连接到Oracle数据库,并且employees表及其列存在且数据完整。此外,如果需要对查询结果...
--查询指定字段 重复记录大于一条的记录,并统计该记录出现的总次数 select b.ent_name,count(ent_name) from z_huhehaote_ent_item b group by b.ent_name having count(b.ent_name) > 1
select t.id from tab t group by t.id having coung(*) >1;
一、背景 一张person表,有id和name的两个字段,id是唯一的不允许重复,id相同则认为是重复的记录。 二、解决 select id from group by id having count(*) > 1 按照id分组并计数,某个id号那一组的数量超过1条则认为重复。http:...
假设你要查的表是mytable,字段是field1:select field1 from mytable group by field1 having count(0) > 1 如果要看所有的字段：select * from mytable where field1 in (select field1 from mytable group by field1 having count(0) > 1 )...
1、查出表中重复列的数据：select a,count(*) from table group by a having count(*)>1 2、查重复次数最多的列：select a,num from (select a,count(*) num from table group by a having count(*)>1)order by num desc 此外，还有 1、查询一个表中所有字段都相同的记录 比如现在有...
--1,查询hm有重复的记录select hm,count(*) from a group by hm having count(*)>1--2,查询hm和xm都有重复select hm,xm count(*) from a group by hm,xm having count(*)>1
--记录第一条: rownum= 1 11、查询‘3-105’号课程的平均分。 SELECT avg(degree) FROM t_score where cno='3-105' 12、查询score表中至少有5名学生选修的并以3开头的课程的平均分数。 SELECT * FROM (SELECT cno FROM t_score group by cno having count(*)>5 ) where cno like'%3%' ...
select count(1) from emp where id<100 group by sex having count(1)>4 having 其实和where一样都是过虑的作用，只是顺序不同，在有分组的时候（group by ）where 是先过虑再分组计算 having是先分组计算再过虑.
select deptno from emp group by deptno having count(*)>1); (24) 查询工资比SMITH员工工资高的所有员工信息。 SELECT * FROM emp where sal>(SELECT sal FROM emp where ename='SMITH') (25) 查询所有员工的姓名及其直接上级的姓名。 SELECT a.ename FROM emp a ,emp b where a.mgr=b.empno ...