Comparing each items to remaining items of a list - list

Question

I am trying to compare each table column with other table's column one by one.
Here is the scenerio
I have three tables like this
and I am getting their information like this as List of TableRow
TableRow(students,INT,10,id)
TableRow(students,VARCHAR,200,name)
TableRow(students,VARCHAR,100,address)
TableRow(department,INT,10,id)
TableRow(department,VARCHAR,100,department_name)
TableRow(teacher,INT,10,id)
TableRow(teacher,INT,10,suvject)
suppose I want to compare each row to remaining rows of other tables like this ->
TableRow(students,INT,10,id) - TableRow(department,INT,10,id)
TableRow(students,INT,10,id) - TableRow(department,VARCHAR,100,department_name)
TableRow(students,INT,10,id) - TableRow(teacher,INT,10,id)
TableRow(students,INT,10,id) - TableRow(teacher,INT,10,suvject)
TableRow(students,VARCHAR,200,name) - TableRow(department,INT,10,id)
TableRow(students,VARCHAR,200,name) - TableRow(department,VARCHAR,100,department_name)
TableRow(students,VARCHAR,200,name) - TableRow(teacher,INT,10,id)
TableRow(students,VARCHAR,200,name) - TableRow(teacher,INT,10,suvject)
TableRow(students,VARCHAR,100,address) - TableRow(department,INT,10,id)
TableRow(students,VARCHAR,100,address) - TableRow(department,VARCHAR,100,department_name)
TableRow(students,VARCHAR,100,address) - TableRow(teacher,INT,10,id)
TableRow(students,VARCHAR,100,address) - TableRow(teacher,INT,10,suvject)
TableRow(department,INT,10,id) - TableRow(teacher,INT,10,id)
TableRow(department,INT,10,id) - TableRow(teacher,INT,10,subject)
TableRow(department,VARCHAR,100,department_name) - TableRow(teacher,INT,10,id)
TableRow(department,VARCHAR,100,department_name) - TableRow(teacher,INT,10,subject)
Therefore I am comparing each tables column to other table's column like above..
I am using code like this to compare it, which works but is there any better approach for doing this ? A good functional way of writing it ?
val stack = mutable.Stack[TableRow]().pushAll(tableRows)
val arrayList = new util.ArrayList[JoinInfo]()
while (stack.nonEmpty) {
val currentRow = stack.pop()
stack.foreach(targetRow => {
if (!(targetRow.tableName.equals(currentRow.tableName) && targetRow.schema.equals(currentRow.schema))) { //not comparing with current table's column with its other column.
arrayList.add(compareColumns(currentRow, targetRow))
}
})
}

Answer 1

I would write something like this :
(tableRows zip tableRows).filter {
case(currentRow, targetRow) => !(targetRow.tableName.equals(currentRow.tableName) && targetRow.schema.equals(currentRow.schema))
}
So, pretty the same thing except it used the zip function to avoid manually writing the double loop.