Customer Department SQL display statement for tree structure data (pure SQL statement)

Tree structure | data | display | statement SELECT dpcode1 as dpcode,dpname1 as Dpname
From Base_custdept where dpcode1>0 and Dpcode2=0 and Dpcode3=0 and dpcode4=0
UNION ALL
SELECT Dpcode1+dpcode2 as dpcode,dpname1+dpname2 as Dpname
From Base_custdept where dpcode1>0 and dpcode2>0 and Dpcode3=0 and dpcode4=0
UNION ALL
SELECT Dpcode1+dpcode2 +dpcode3 as dpcode,dpname1+dpname2+dpname3 as Dpname
From Base_custdept where dpcode1>0 and dpcode2>0 and Dpcode3>0 and dpcode4=0
UNION ALL
SELECT Dpcode1+dpcode2 +dpcode3+dpcode4 as dpcode,dpname1+dpname2+dpname3+dpname4 as Dpname
From Base_custdept where dpcode1>0 and dpcode2>0 and Dpcode3>0 and dpcode4>0