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在操作中,有时要用几个数据造成一查询表处理数据,通常的做法是select union all,现提供另一种方法:
SELECT * FROM (VALUES (1,2),(3,4),(5,6)) AS t(a,b) 相当于 SELECT * FROM( SELECT 1 a, 2 b UNION ALL SELECT 3 a,4 b UNION ALL SELECT 5 a,6 b )t