In Symfony2, if I embed a collection of forms pointing at a many to one relationship in Doctrine and allow adding and deletion, if I delete a record from the beginning, add one at the end, and edit some in the middle how does the system know which records to update with which data?
在Symfony2中，如果我在Doctrine中嵌入指向多对一关系的表单集合并允许添加和删除，如果我从头开始删除一条记录，最后添加一条，并在中间编辑一些如何系统知道哪些记录要更新哪些数据？
There is nothing in the tutorial that passes the primary key of the embedded data around. Under certain circumstances, my records are getting needlessly deleted and added again rather than edited in place (even if there are no changes to the particular record). This breaks the fields on the records that are not included on the form, setting them to their default values from the DB model.
教程中没有任何内容可以传递嵌入数据的主键。在某些情况下，我的记录会被不必要地删除并再次添加，而不是在适当的位置进行编辑（即使特定记录没有变化）。这会破坏表单上未包含的记录中的字段，并将其设置为DB模型中的默认值。
Is there a way to pass the primary key in the form and have it used to perform updates when the data comes back?
有没有办法在表单中传递主键并在数据恢复时用它来执行更新？
3 个解决方案
#1
3
If you want to index the collection (by the entity id) for all querys, you can simply use the indexBy annotation in your entity class.
如果要为所有查询索引集合（通过实体ID），则只需在实体类中使用indexBy批注即可。
/**
* @ORM\OneToMany(targetEntity="EntityClass", mappedBy="EntityVariable", indexBy="id")
*/
private $collection;
#2
1
Based on the Akkumulator's answer and comment and some experimentation, I did this:
基于Akkumulator的回答和评论以及一些实验，我这样做了：
Create new fields (using Javascript as described in the documentation) with __name__ replaced not by a number but by a string: new_ followed by an forever increasing number that has nothing to do with the list (e.g. new_1, new_2, new_3...)
使用__name__创建新字段（使用Javascript，如文档中所述），不是用数字而是用字符串替换：new_后跟一个与列表无关的永久增加的数字（例如new_1，new_2，new_3 ......）
I don't have to push the primary keys into the forms and I don't need indexBy either - that's good, because indexBy felt like it was too far removed from the form, ending in having the Action at a distance anti-pattern.
我没有必要将主键推入表单中，我也不需要indexBy - 这很好，因为indexBy觉得它离表单太远了，最终导致Action远程反模式。
Why this works:
为何如此有效：
- PHP arrays aren't like those in other languages. They're always dictionaries, so you can add string keys to them even if they only have numeric keys to start with.
- PHP数组与其他语言不同。它们总是字典，所以你可以为它们添加字符串键，即使它们只有数字键开头。
- Because the Symfony collection is mapped by field name, new fields will not match existing data and deleted fields will not be matched to existing data (and thus be removed from the set)
- 由于Symfony集合是按字段名称映射的，因此新字段将不匹配现有数据，并且已删除字段将不会与现有数据匹配（因此将从集合中删除）
#3
0
One way to pass primary id is to use INDEX BY.
传递主要ID的一种方法是使用INDEX BY。
For example, say I have an entity called Customer and a Customer has several Emails. In my Customer repository class, I can specify my collection to be indexed by Email's primary id.
例如，假设我有一个名为Customer的实体，而Customer有几个电子邮件。在我的Customer存储库类中，我可以指定要通过Email的主ID进行索引的集合。
$qb->select('c, e')
->leftJoin('c.emails', 'e', null, null, 'e.id')
->where('c.id = :id');
By doing so, the generated name of the input tag would be
通过这样做，生成的输入标记的名称将是
customer[emails][e.id][fieldName]
Upon submitting the form, Symfony will bind the request values according to the input names.
提交表单后，Symfony将根据输入名称绑定请求值。
#1
3
If you want to index the collection (by the entity id) for all querys, you can simply use the indexBy annotation in your entity class.
如果要为所有查询索引集合（通过实体ID），则只需在实体类中使用indexBy批注即可。
/**
* @ORM\OneToMany(targetEntity="EntityClass", mappedBy="EntityVariable", indexBy="id")
*/
private $collection;
#2
1
Based on the Akkumulator's answer and comment and some experimentation, I did this:
基于Akkumulator的回答和评论以及一些实验，我这样做了：
Create new fields (using Javascript as described in the documentation) with __name__ replaced not by a number but by a string: new_ followed by an forever increasing number that has nothing to do with the list (e.g. new_1, new_2, new_3...)
使用__name__创建新字段（使用Javascript，如文档中所述），不是用数字而是用字符串替换：new_后跟一个与列表无关的永久增加的数字（例如new_1，new_2，new_3 ......）
I don't have to push the primary keys into the forms and I don't need indexBy either - that's good, because indexBy felt like it was too far removed from the form, ending in having the Action at a distance anti-pattern.
我没有必要将主键推入表单中，我也不需要indexBy - 这很好，因为indexBy觉得它离表单太远了，最终导致Action远程反模式。
Why this works:
为何如此有效：
- PHP arrays aren't like those in other languages. They're always dictionaries, so you can add string keys to them even if they only have numeric keys to start with.
- PHP数组与其他语言不同。它们总是字典，所以你可以为它们添加字符串键，即使它们只有数字键开头。
- Because the Symfony collection is mapped by field name, new fields will not match existing data and deleted fields will not be matched to existing data (and thus be removed from the set)
- 由于Symfony集合是按字段名称映射的，因此新字段将不匹配现有数据，并且已删除字段将不会与现有数据匹配（因此将从集合中删除）
#3
0
One way to pass primary id is to use INDEX BY.
传递主要ID的一种方法是使用INDEX BY。
For example, say I have an entity called Customer and a Customer has several Emails. In my Customer repository class, I can specify my collection to be indexed by Email's primary id.
例如，假设我有一个名为Customer的实体，而Customer有几个电子邮件。在我的Customer存储库类中，我可以指定要通过Email的主ID进行索引的集合。
$qb->select('c, e')
->leftJoin('c.emails', 'e', null, null, 'e.id')
->where('c.id = :id');
By doing so, the generated name of the input tag would be
通过这样做，生成的输入标记的名称将是
customer[emails][e.id][fieldName]
Upon submitting the form, Symfony will bind the request values according to the input names.
提交表单后，Symfony将根据输入名称绑定请求值。