play_classification=30,count(distinct t.play_name_zh),0) as '动画片部数', -- 集数all_play_num SUM(CASE when t.play_classification = 10 then t.submit_num else 0 end ) as '电视剧集数' , SUM(CASE when t.play_classificatio
mysql count(distinct case when condition1 then field1，field2，field3 end) as result不允许在case...
#count(1):根据第一列统计记录总数,包含重复的记录,包含为NULL或空的值。也可以使用count(2) #count(列名):根据指定的列统计记录总数,包含重复的记录,不包括NULL或空的值。 #count(distinct 列名):根据指定的列统计记录总数,不包含重复的记录,不包括NULL或空的值。 写出一个SQL 查询语句,计算每个雇员的奖金。...
1 COUNT(CASEWHENA.expire_time<{0}ANDA.expire_time<>0THENA.expire_timeEND)ASdisabled_total 对部分列去重 1 DISTINCTucd.course_id,ucd.user_idandCASEWHENucd.kind=0THENucd.kindEND
CASE (SELECT NOW() > '2019-02-12 16:48:00')WHEN 1 THEN '男'WHEN 2 THEN '⼥'ELSE '未知'END as ages COUNT(CASE WHEN A.expire_time<{0} AND A.expire_time<>0 THEN A.expire_time END) AS disabled_total 对部分列去重 DISTINCT ucd.course_id,ucd.user_id and CASE WHEN ucd...
1.count(*) 、 count(n)、count(null)与count(fieldName)2.distinct 与 count 连用3.group by (多个字段) 与 count 实现分组计数4.case when 语句与 count 连用实现按过滤计数 参考文章:Select count(*)和Count(1)的区别和执行方式 准备工作 -- 创建表 CREATE TABLE `tb_student` ( `id` int(11) NO...
SUM(CASE WHEN is_active = 1 THEN 1 ELSE 0 END) AS '已激活数量',COUNT(DISTINCT is_active) ...
Description: Consider a sql like: select count(distinct case when xxx then f end) from tb; When tmp_table_size is too small to fill all the rows, merge_walk needed. But when merge_walk, it check the condition again, using THE LAST row in the match result set. This leads to bug ...
1. 2. 3. 4. 5. 6. 7. COUNT(CASEWHENA.expire_time<{0}ANDA.expire_time<>0THENA.expire_timeEND)ASdisabled_total 1. 对部分列去重 DISTINCTucd.course_id,ucd.user_idandCASEWHENucd.kind=0THENucd.kindEND 1.
-- 在支持窗口函数的 sql 中使用 select count(case when rn=1 then task_id else null end) task_num from (select task_id , row_number() over (partition by task_id order by start_time) rn from Task) tmp; 此外,再借助一个表 test 来理理 distinct 和 group by 在去重中的使用: -- 下...