似乎你的期望是得到的线索，购买和收入的总和。请使用下面的查询，

SELECT
a.Country,    a.Date,    a.Source,    a.Campaign,    sum(a.Leads)    sum(b.purchases),    sum(b.revenue)
FROM
 Table A 
 LEFT JOIN 
 Table B 
ON a.country = b.country and a.date = b.date and a.source = b.source and a.campaign = 
b.campaign;

如果这不是你所期望的，请提供样品数据和你的预期结果。为您提供解决方案会更有帮助

如果需要从两个表中获取所有数据，我认为需要使用完全外部联接：

SELECT
ifnull(a.country,b.country) country,
ifnull(a.date,b.date) date,
ifnull(a.source,b.source) source,
ifnull(a.campaign,b.campaign) campaign,
a.leads,
b.purchases,
b.revenue

FROM
Table A 
FULL OUTER JOIN 
Table B 

ON a.country = b.country and a.date = b.date and a.source = b.source and a.campaign = b.campaign

如果我误解了你的问题，请提供一个样本数据
更新：
试试这个：

WITH
  table_a AS (
  SELECT
    'A' Country,
    '2020-01-01' Date,
    'X' Source,
    'L' Campaign,
    100 Leads
  UNION ALL
  SELECT
    'A' Country,
    '2020-01-01' Date,
    'X' Source,
    'L' Campaign,
    200 Leads
  UNION ALL
  SELECT
    'B' Country,
    '2020-01-01' Date,
    'Y' Source,
    'M' Campaign,
    300 Leads
  UNION ALL
  SELECT
    'B' Country,
    '2020-01-01' Date,
    'Y' Source,
    'M' Campaign,
    400 Leads ),
  table_b AS (
  SELECT
    'A' Country,
    '2020-01-01' Date,
    'X' Source,
    'L' Campaign,
    100 Purchases,
    100000 revenue
  UNION ALL
  SELECT
    'A' Country,
    '2020-01-01' Date,
    'X' Source,
    'L' Campaign,
    200 Purchases,
    30000
  UNION ALL
  SELECT
    'B' Country,
    '2020-01-01' Date,
    'Y' Source,
    'M' Campaign,
    400 Purchases,
    40000
  UNION ALL
  SELECT
    'C' Country,
    '2020-01-01' Date,
    'X' Source,
    'L' Campaign,
    200 Purchases,
    30000)
SELECT
  ifnull(a.country,
    b.country) country,
  ifnull(a.date,
    b.date) date,
  ifnull(a.source,
    b.source) source,
  ifnull(a.campaign,
    b.campaign) campaign,
  a.leads,
  b.purchases,
  b.revenue
FROM
  table_a a
FULL OUTER JOIN
  table_b b
ON
  a.country = b.country
  AND a.date = b.date
  AND a.source = b.source
  AND a.campaign = b.campaign

假设你的 join 产品条件不重复，建议使用 full join 与 using :

SELECT country, date, source, campaign,
       COALESCE(a.leads, 0) as leads,
       COALESCE(b.purchases, 0) as purchases,
       COALESCE(b.revenue, 0) as revenue
FROM TableA a FULL JOIN
     TableB b
     USING (country, date, source, campaign);

这将保留两个表中的所有行。这个 USING 从句容易避免 NULL 中使用的键列上的值 JOIN . 这个 COALESCE() 是因为我猜你真的想要 0 只在一个表中的行的值—但如果您对该值满意，可以将其删除 NULL .