如何查询两个不同的mysql表并比较结果

Question

我有两个Mysql查询：

1：

select TblC.name, 
SUM(TblC.total) as Sum
from TblC
left join TblCli on TblC.id_cli = TblCli.id 
group by TblCli.name asc

结果是

 NAME     SUM
 john    1000
 peter    500
 Alicia   300

2：

select TblCli.name, 
SUM(TblRec.total) as Pay
from TblRec
left join TblCli on TblRec.id_cli = TblCli.id 
group by TblCli.name asc

结果是

NAME    Pay
john    500
peter   100

有两个不同的表没有直接关系 我需要加入这两个查询并获得如下结果：

NAME      SUM    PAY  Difference
john      1000   500         500
peter     500    100         400
Alicia    300    0           300

我该怎么做？