title: convert row values to single column as array (or to multiple columns)
body: <p>I have 3 tables e.g.
  emptable, tax (1:m with emptable using empid), deductions (1:m with emptable using empid)</p>
  <pre><code>========== emptbl ==========
  empid, totaltax, totaldeductions...
  001, 100, 50
  
  ========== tax ========== taxes can be 1 line item per empid or many line items
  empid, date, tax_line_item, tax, tax_type...
  001, 12-15-2021, 1, 25, A
  001, 12-15-2021, 2, 30, B
  001, 12-15-2021, 3, 25, C
  
  ========== deductions ========== deductions can be 1 line item per empid or many line items
  empid, date, ded_line_item, deduction, deduction_type...
  001, 12-15-2021, 1, 12.5, W
  001, 12-15-2021, 2, 12.5, 401
  001, 12-15-2021, 3, 20, I
  001, 12-15-2021, 4, 5, B
  
  Desired result
  
  ========== RESULT ==========
  empid, totaltax, totaldeductions, taxes (as array), tax_type , deductions (as array), deduction_type
  001,   100,      50,              25,       A,        12.5,        W
                                    30        B,        12.5,        401
                                    25        C,        20,          I
                                                        5,           B
  </code></pre>
  <p>If I use the emptable and tax, I would get 1 row and the taxes column as array, which is what I want to achieve but when I join the 3 tables and use array_agg to get the RESULT#2, i get 12 rows (1x3x4) instead of just 4 rows total.</p>
  <p>Is there a way a could get the desired result. I appreciate any leads on how to make it happen.</p>