hive 行轉列

用max（if()）将行轉換列

表 

　　flag

ret_1      

ret_3      

ret_7

      

max(if (flag = 'ret_1', ret_user, NULL)) as ret1_user,

max(if (flag = 'ret_3', ret_user, NULL)) as ret3_user,

max(if (flag = 'ret_7', ret_user, NULL)) as ret7_user