**Is your feature request related to a problem? Please describe.** - [refactor: code modification to ensure data consistency](https://github.com/Stocks-Are-Everywhere/backend/commit/3d9718f97733412eb5ff5f9f9669c3196af181d3) - [test: create test code to ensure data consistency](https://github.com/Stocks-Are-Everywhere/backend/commit/4948558de49b66daed7896058cf5286ce595cc5f) **Describe the solution you'd like** **Describe alternatives you've considered** **Additional context**