A左连接B===>S1区域

1、等价方式一

SELECT date, ts, country, province, city,ye_no
FROM
(SELECT date, ts, country, province, city,0 AS yes_no
FROM DBa.tba 
WHERE (date = today()-1) 
)
ALL LEFT JOIN 
(SELECT date, ts, country, province, city
FROM DBb.tbb  
WHERE (date = today()-1)
AND cid != '1sk309'
) USING ( date, ts, country, province, city)

2、等价方式二

SELECT date, ts, country, province, city,ye_no
FROM
(SELECT date, ts, country, province, city,0 AS yes_no
FROM DBa.tba 
WHERE (date = today()-1) 
) AS A
ALL LEFT JOIN 
(SELECT date, ts, country, province, city
FROM DBb.tbb  
WHERE (date = today()-1)
AND cid != '1sk309'
) AS B
ON ( A.date=B.date, A.ts=B.ts, A.country=B.country, A.province=B.province, A.city=B.city)