在MySQL中按月份和年份分组

给定一个每行有一个时间戳的表，你将如何格式化查询以适应这个特定的json对象格式。

我试图组织一个json对象到几年/几个月。

json将查询closures：

{ "2009":["August","July","September"], "2010":["January", "February", "October"] } 

这是我到目前为止的查询 –

 SELECT MONTHNAME(t.summaryDateTime) as month, YEAR(t.summaryDateTime) as year FROM trading_summary t GROUP BY MONTH(t.summaryDateTime) DESC"; 

这个查询正在打破，因为它（可预测地）将不同的年份结合在一起。

Answer 1

 GROUP BY YEAR(t.summaryDateTime), MONTH(t.summaryDateTime) DESC; 

是你想要的。

Answer 2

 GROUP BY DATE_FORMAT(summaryDateTime,'%Y-%m') 

Answer 3

 SELECT MONTHNAME(t.summaryDateTime) as month, YEAR(t.summaryDateTime) as year FROM trading_summary t GROUP BY YEAR(t.summaryDateTime) DESC, MONTH(t.summaryDateTime) DESC 

应该使用年和月的DESC来获得正确的顺序。

Answer 4

我更喜欢

 SELECT MONTHNAME(t.summaryDateTime) as month, YEAR(t.summaryDateTime) as year FROM trading_summary t GROUP BY EXTRACT(YEAR_MONTH FROM t.summaryDateTime) DESC"; 

Answer 5

你必须这样做

 SELECT onDay, id, sum(pxLow)/count(*),sum(pxLow),count(`*`), CONCAT(YEAR(onDay),"-",MONTH(onDay)) as sdate FROM ... where stockParent_id =16120 group by sdate order by onDay 

Answer 6

像这样使用EXTRACTfunction

 mysql> SELECT EXTRACT(YEAR FROM '2009-07-02'); -> 2009 

Answer 7

您只是按月分组，您必须将YEAR（）添加到组中

Answer 8

 SELECT YEAR(t.summaryDateTime) as yr, GROUP_CONCAT(MONTHNAME(t.summaryDateTime)) AS month FROM trading_summary t GROUP BY yr 

你仍然需要在外部脚本中处理它，以获得你正在寻找的结构。

例如，使用PHP的explode从月份名称列表创build一个数组，然后使用json_encode（）

Answer 9

使用

 GROUP BY year, month DESC"; 

代替

 GROUP BY MONTH(t.summaryDateTime) DESC";