如果仅当当前字段存在于数组中时如何计算或求和字段答案

【问题标题】：How to count or sum fields if only if the current field exists in an array如果仅当当前字段存在于数组中时如何计算或求和字段
【发布时间】：2018-02-08 21:24:11
【问题描述】：

我有以下疑问：

SELECT 
count(form_rows.field_name), 
form_rows.field_name, 
sum(form_rows.field_value) as sales, 
form_Submissions.id as fsId 
FROM form_submissions
LEFT JOIN form_rows on form_Submissions.id = form_rows.form_submission_id
WHERE form_submissions.organization_id = 10
GROUP BY form_rows.field_name

这会重现以下结果：

问题：有没有办法根据field_nameSUM 和COUNT

澄清：

假设我有一个数组：["ssn", "price"]

我只想对sales 求和，即field_names 存在于给定数组中

【问题讨论】：

标签： mysql sql database mongodb

【解决方案1】：

这样不行吗：

SELECT 
count(form_rows.field_name), 
form_rows.field_name, 
sum(form_rows.field_value) as sales, 
form_Submissions.id as fsId 
FROM form_submissions
LEFT JOIN form_rows on form_Submissions.id = form_rows.form_submission_id
WHERE form_submissions.organization_id = 10

AND form_rows.field_names in ('ssn','price')

GROUP BY form_rows.field_name

【讨论】：

太棒了，我完全忘记了那个选项！因为这只是怪物查询中的一个子查询。