The query select 1 from Double where false Return 0 rows, but the query select max(1) from Double where false Return 1 row with NUL content.
原因何在?
A query with a where 1=0 clause filters out all rows, and returns an empty set.
整个表格中按合计数分列的无一组的合计数。 如果表内没有行文,则上限为<代码>null,但该表仍在计算总合数。
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