规则是,一旦引入了关联表,复合度就“交叉”,如图12所示。
The rule is that the multiplicities "cross over" once the associative table is introduced, as indicated in Figure 12.
把人生比成故事其实是指,人们回看人生就像看到若干的故事线一般,平行也好,交叉也罢,或全无关联。
What it means rather is that, if one reflected on one's life, one could reasonably see it in terms of various story lines, whether parallel or intersecting or distinct.
一个没有WHERE子句的交叉联接,会产生所关联表的笛卡尔乘积。
A cross join that does not have a WHERE clause produces the Cartesian product of the tables involved in the join.
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