NightPxy 个人技术博客

Sql-join

Posted on Jul 11, 2018 By NightPxy

概述

api

join vs joinWith

  • join
    join之后,schema等于两个数据集相加(类别RDBMS的join)
  • joinWith
    joinWith之后,schema将表示为turple2=> _1为数据集1,_2为数据集2