You might want to start with database answers. This is a large collection of database models, offered for free. Many of them have no implementation alonmg with them, so they are just a starting point for a do it yourself project. But the author has done a lot of work clarifying the problem. I don’t … Read more
It’s called Polymorphic relationship (association). And you can’t have a column (added_by in your case) that references two parent tables simultaneously. But what you can do to be able to use foreign key constraints is to have two nullable columns added_by_super_admin and added_by_admin only one of which will hold the value per record. CREATE TABLE … Read more
SELECT * FROM student_certificates GROUP BY student_id HAVING COUNT([DISTINCT] certificate_id) >= 20 Join students table if some columns from it needed (do not forget to expand GROUP BY expression accordingly). 1 solved sql get query to get any student records who have passed multiple certificates? [closed]
There is no way insertion in a table can check whether that primary key is present in another table apart from either forcing this constraint through business rule or by using DB Trigger. You need to analyse your DB Model again and try to identify a good design. 1 solved IS_A relationship primary key validation … Read more
I’m guessing from what little you have written that you want a variable list of fields (where the list of fields is retrieved from tableB) to be retrieved from tableA. This isn’t possible directly in SQL. You will need to make 2 calls, the first one to retrieve the list of fields, and the second … Read more