Diagram 8: Identify Each Record's "Parent Id"

        id,parent_id,"path","nationality","gender","age","income"
        1,,"|Alpha","","","",""
        2,1,"|Alpha|Epsilon","","","",""
        3,2,"|Alpha|Epsilon|Kappa","","","",""
        4,1,"|Alpha|Zeta","","","",""
        5,4,"|Alpha|Zeta|Lambda","","","",""
        6,4,"|Alpha|Zeta|Mu","","","",""
        7,,"|Beta","","","",""
        8,7,"|Beta|Eta","","","",""
        9,7,"|Beta|Theta","","","",""
        10,,"|Gamma","","","",""
        11,10,"|Gamma|Iota","","","",""
        12,11,"|Gamma|Iota|Delta","","","",""
        13,,"|Delta","","","",""