There is a super class
account {User, TYPE}
and subclasses
saving{User, ID, balance,TYPE,interest,curency_TYPE}
time{User,ID,balance,TYPE,interest,curency_TYPE,start_date,due_date,period}
fore{User,ID,balance,interest,curency_TYPE}
User and TYPE is the primary key of account and foreign key of three subclasses
ID is primary key of three subclasses
how to make a list of showing all IDs in one column?Also the same as balance and TYPE meet the problem
I considered a.ID as saving, b.ID as time but it showing them separately