mysql - SQL总结单词的麻烦

Question

我正在Sum()尝试Status. Status = 'operational'我无法弄清楚如何总结实际的“操作”一词。

我尝试了以下语句的多种不同变体（我发布的是最基本的形式），但我收到错误：data type varchar is invalid for sum operator.

有人可以帮忙吗？

SELECT SUM(status) As 'TotalOperationalSTIDevices'
FROM netinfo_device_details
WHERE LoopBackAddress LIKE '10.12%' AND Status = 'Operational'

score 1 · Accepted Answer

您需要使用 COUNT：

SELECT COUNT(*) As TotalOperationalSTIDevices 
FROM netinfo_device_details 
WHERE LoopBackAddress LIKE '10.12%' AND Status = 'Operational';

SUM 聚合函数实际上是对一组数字进行求和。COUNT 只计算行数。由于该行的实际内容不相关，因此您可以根据需要使用 COUNT(*) 而不是 COUNT(status)。

score 1 · Accepted Answer

尝试

Select COUNT(*) As 'TotalOperationalSTIDevices' from netinfo_device_details where LoopBackAddress Like '10.12%' and Status = 'Operational'

2 回答 2