JIRA portfolio plan issues database table

[ANTONIO GOMEZ ASENCIO]

I am trying to retrieve issues in a portfolio plan from JIRA database for reporting purposes and this is similar to JQL function  issuekey in issuesInPlan(""). I was able to retrieve plan details from  AO_D9132D_PLAN table and I am trying to figure out where the issues for a portfolio are stored in JIRA databse. 

I have tried querying AO_D9132D_ASSIGNMENT_EXT table but that has inaccurate data or some relational mapping behind the scenes - I was not able to fetch all the issues in a plan. This query will help me to generate the report automatically without me intervening to run JQL and download as an excel and upload to a reporting tool. Any help is much appreciated. 

Note : RestAPI is a pain with my current reporting platform so I don't want to get results using it.