我有两个表，production和sales，并尝试将这两个表合并为一个表。
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我可以像下面这样合并表格，但它不包括只有销售数字的月份。我怎样才能用一个月的零来填充这个月的销售量呢？
select
EXTRACT(year from s.Date) as Year,
EXTRACT(month from s.Date) as Month,
p.Quantity as Production,
s.Sales
FROM Prodcution p, Sales s
WHERE
EXTRACT(year from s.Date) = EXTRACT(year from p.Date)
AND EXTRACT(month from s.Date) = EXTRACT(month from p.Date)转载请注明出处:http://www.lsql.net/article/20230429/2455370.html