schema);错误是:at javax.xml.parsers.DocumentBuilderFactory.setSchema(Unknown Source)
at org.xmlcml.graphics.misc.SchemaTest.testValidatingParser1(SchemaTes
是否有一种显式指定空聚合的方法,如:而不是没有GROUP BY子句的隐式版本:SELECT NULL AS Product, SUM(Revenue) FROM SalesWITH Sales (Product, Revenue) AS (VALUES ('a',10),('b',20))
select NULL Product, S