Question

sql查询语句计算重复数据个数

select DISTINCT mypage from deyebcount

如何写sql可以得到每一个行重复的个数呢？按照由大到小排列

Answer 1

1、创建测试表，

create table test_count(id varchar2(20)， value varchar2(20));

2、插入测试数据

insert into test_count values(1, 1);

insert into test_count values(2, 1);

insert into test_count values(3, 1);

insert into test_count values(4, 2);

insert into test_count values(6, 1);

insert into test_count values(7, 3);

insert into test_count values(8, 3);

insert into test_count values(9, 3);

insert into test_count values(10, 3);

commit;

3、查询表中全量数据，select t.*， rowid from test_count t;

4、编写sql，可以得到每一个value重复的个数，并按照由大到小排列；

   select value, count(*) from test_count t group by value order by 2 desc

Answer 2

sql 计算重复数据个数 可以使用 count 来统计
例子
personal表
id name
1 xm
2 xm
3 mx
统计personal表中name为xm的个数
select count(name) total from personal where name='xm'
结果
total
2

Answer 3

select count(*),字段名 from 表名
group by 字段名 having count(*)>1

Answer 4

DISTINCT 是去重复值!
select count(mypage) as s from deyebcount group by mypage order by mypage desc;

Answer 5

SELECT count(*),aa,,BB,CC FROM A GOURP BY AA,BB,CC