原则 2:如何处理带有额外列的连接表 [英] Doctrine 2: How to handle join tables with extra columns
问题描述
如何在 Doctrine 2 中设置带有额外列或多对多关联的连接表?
How do I setup a join table with extra columns, or a many-to-many association with additional properties, in Doctrine 2?
推荐答案
首先，让我解释一下，这不存在:
First off, let me explain that this does not exist:
join table(也称为 junction table 或 cross-reference table)是链接 2 个(或更多)的表格同一个数据库中的其他表通过主键放在一起.这意味着连接表将只包含外键，这些额外的列没有位置.
A join table (also known as a junction table or cross-reference table) is a table that links 2 (or more) other tables together within the same database by primary key. This means that a join table will only contain foreign keys, there is no place for these extra columns.
所以当你需要在这样的表中添加额外的列时，它不再只是一个链接"；在其他表之间，但自己成为真正的表！
So when you need extra columns in such a table, it is no longer just a "link" between other tables, but becomes a real table on its own!
就 Doctrine 2 而言，您不再拥有 2 个实体之间的多对多关联，而是获得 3 个实体之间的一对多/多对一关联.
In terms of Doctrine 2, you no longer have a many-to-many association between 2 entities, but get a one-to-many/many-to-one association between 3 entities.
继续阅读此处以获得更详细的解释:
Continue reading here for more detailed explanations:
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