SQL Inner Join

SELECT t1.username AS Pengguna, t2.username AS Upline
FROM reseller t1
INNER JOIN reseller t2 ON t2.user_id = t1.parentID
LIMIT 0 , 30

http://www.sqltutorial.org/sqlselfjoin.aspx

SELECT column_list FROM table_A A INNER JOIN table_A B ON A.column_name1 = B.column_name2…. WHERE row conditions