[Improvement][Task SQL] There is no need to send an email when the sql result is empty

[chenshuai1995]

Search before asking

• I had searched in the issues and found no similar feature requirement.

Description

When the sql result is empty, it still keeps sending the email, and the content of the email is empty.

The expectation is that if the query result is not empty, it is normal to send an alert email, but if the query result is empty, there is no need to send the email.

Are you willing to submit a PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[liukunyuan]

It is a good idea! But add a new monito sql node would be better

[qingwli]

I am +0 about this. Some users can use this function to monitor, an empty value is the result at some time. For this function , we can use two ds tasks to achieve this function, It's more flexible

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity for 30 days. It will be closed in next 7 days if no further activity occurs.

[github-actions]

This issue has been closed because it has not received response for too long time. You could reopen it if you encountered similar problems in the future.