结果删除重复我具有低于使用MySQL和PHP
SELECT A.order_no, A.order_date,
COUNT(B.reaction_no) as tot_reaction_no,
SUM(CASE
WHEN (B.purification != '') THEN 1
ELSE 0
END) as tot_purification
FROM order_header A
LEFT JOIN order_reactions B ON A.order_no = B.order_no
WHERE A.order_date BETWEEN '2015-10-01 00:00:00' AND '2016-09-01 00:00:00'
AND A.order_no = '23746'
GROUP BY A.order_no
一个查询给定的,这将结果示于图片。但结果是错误的,因为一些条目是重复的。所以我必须删除重复并打印计数。计数需要的是“列”的计数从表1
也许您可以在查询中使用distinct关键字 – DBX12
[MySQL:仅选择列中的唯一值](http:// stackoverflow。 com/questions/8571902/mysql-select-only-unique-values-from-a-column) –
当我使用DISTINCT –