Does Sprint ID have a relationship with Issue Key in JIRA DB Schema?

[Jira ril]

I was looking at JIRA DB Schema and found out that there is no linkage between a sprint ID and Issue ID.
According to the flow, Issues are part of Sprints/Linked with them.

I wanted to get sprint wise Issue data by leveraging DB without PLUGINs

[Nic Brough -Adaptavist-]

No, the database contains no relationships at all, they are all done in the code.

"Leveraging the db" is the worst possible way you can report on Jira data.  You should stop it, and use the REST API (which will report issues in a sprint in one simple question/response instead of the six joins you'd need in a database)