说明:group by是sql中对数据表中的数据进行分组的,在select列表中出现的字段必须全部出现在group by 字段中,出现在聚合函数中的字段在group by中可有可无,没有出现在select列表中的字段在group by中也可以使用.在group by中不可以使用列别名. 语法:select column_name,aggregate_function(column_name) from table_name where column_name operator value gro
转载源:http://www.jb51.net/article/42613.htm SQL按照日.周.月.季度.年统计数据的方法 方式一: --按日 select sum(consume),day([date]) from consume_record where year([date]) = '2006' group by day([date]) --按周quarter select sum(consume),datename(week,[date]) from consume_record
/*查询2小时前的数据*/select * from tableName WHERE create_time HOUR) SELECT count(id) FROM rd_track_info WHERE DATE(create_time) DAY); SELECT count(id) FROM rd_track_info WHERE DATE(create_time) DAY); SELECT count(id) FROM rd_track_info WHERE DATE(create_tim
group by DATE_FORMAT(createtime,'%Y-%m');//按月统计数据 group by DATE_FORMAT(createtime,'%Y-%m-%d');//按天统计数据 +---------------------------------+----------+ | DATE_FORMAT(createtime,'%Y-%m') | count(*) | +---------------------------------+----------+ | | |
查看最新用户表统计信息 select owner,table_name,last_analyzed from dba_tables where owner not like '%SYS%' order by 1,3; SELECT Table_Name,Num_Rows,Blocks,Empty_Blocks,Avg_Space,Chain_Cnt,Avg_Row_Len,Sample_Size,Last_AnalyzedFROM Dba_Tables WHERE owner = 'SCOTT'
本位出处:http://www.cnblogs.com/wy123/p/6770258.html 统计信息写过几篇了相关的文章了,感觉还是不过瘾,关于统计信息的问题,最近又踩坑了,该问题虽然不算很常见,但也比较有意思.相对SQL Server 2012,发现在新的SQL Server版本(2014,2016)中都有一些明显的变化,下文将对此进行粗浅的分析. SQL Server 2012中(包括之前的版本),因表中数据变化,但统计信息尚未更新的情况下,对于直方图中没有覆盖到的谓词过滤时,sqls
PROCEDURE SET_TABLE_STATS Argument Name Type In/Out Default? ------------------------------ ----------------------- ------ -------- OWNNAME VARCHAR2 IN TABNAME VARCHAR2 IN PARTNAME VARCHAR2 IN DEFAULT STATTAB VARCHAR2 IN DEFAULT STATID VARCHAR2 IN DE
按周 select DATE_FORMAT(create_time,'%Y%u') weeks,count(caseid) count from tc_case group by weeks; 按月 select DATE_FORMAT(create_time,'%Y%m') months,count(caseid) count from tc_case group by months; 按天 select DATE_FORMAT(create_time,'%Y%m%d')