sql 查询哪些字段重复及（in和exict的区别）

select count(1),content_id,keyword_id from tb_content_keyword_relation group by content_id,keyword_id having count(1)>1 order by count(1) desc

SELECT
	id
FROM
	tb_bds_sys_user
WHERE
	del_flag = '0'
	AND id IN (
	SELECT
		user_id
	FROM
		tb_bds_sys_user_role
	WHERE
		role_id = ( SELECT id FROM tb_bds_sys_role WHERE enname = 'KHJL' ) UNION
	SELECT
		user_id
	FROM
		tb_bds_user_role_data
	WHERE
		role_id = ( SELECT id FROM tb_bds_sys_role WHERE enname = 'KHJL' )
	)

	SELECT c.id FROM tb_bds_sys_user  c
WHERE  EXISTS(
select user_id from (
SELECT
		user_id
	FROM
		tb_bds_sys_user_role
	WHERE
		role_id = ( SELECT id FROM tb_bds_sys_role WHERE enname = 'KHJL' ) UNION
	SELECT
		user_id
	FROM
		tb_bds_user_role_data
	WHERE
		role_id = ( SELECT id FROM tb_bds_sys_role WHERE enname = 'KHJL')
		) ur where ur.USER_ID = c.id
 ) and c.del_flag = '0'