SQL中Union合并结果并去重,Union All合并所有结果,包括重复行。 1、 UNION 操作符可将多个 SELECT 语句查询结果合并成一个结果集。 2、 使用 UNION 时,各 SELECT 语句的列数必须相等,对应列的数据类型需相近,且每条语句中列的排列顺序应保持一致。 3、 SQL中的UNION ...
I need to form the equivalent of a Union Join in Oracle 8i, even though a Union Join doesn't appear to be supported in 8i. I might be able to manipulate a Full Outer Join to get the results I need, ...