If the line appears solid, the DBMS enforces referential integrity for the relationship when rows are added or modified in the foreign-key table.

如果为实线，则当在外键表中添加或修改行时，DBMS将强制关系的引用完整性。

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If the line appears dotted, the DBMS does not enforce referential integrity for the relationship when rows are added or modified in the foreign-key table.

如果为点线，则当在外键表中添加或修改行时，DBMS不强制关系的引用完整性。

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For a one-to-many relationship, the foreign-key table is the table near the line's figure-eight symbol.

对于一对多关系，外键表是靠近线的无穷符号的那个表。

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