在数据源中删除DataAdapter.Fill方法（）行为的行 [英] DataAdapter.Fill() behavior for row deleted at the data source

问题描述

我使用了数据集 / 数据表 / DataAdapter的架构，数据库和我的模型对象，它们有自己的支持（他们不是一个DataRow支持）之间进行调停。我有一个 DataAdapter的与 AcceptChangesDuringFill =假， AcceptChangesDuringUpdate =假和 FillLoadOption = OverwriteChanges 。这是我的理解 DataAdapter的在这些条件下的模型：

I'm using the DataSet/DataTable/DataAdapter architecture to mediate between the database and my model objects, which have their own backing (they aren't backed by a DataRow). I've got a DataAdapter with AcceptChangesDuringFill = False, AcceptChangesDuringUpdate = False, and FillLoadOption = OverwriteChanges. Here's my understanding of the DataAdapter model under these conditions:

• DataRowState.Added 将导致的InsertCommand 烧成
• DataRowState.Modified 将导致更新命令烧成
• DataRowState.Deleted 将导致的DeleteCommand 烧成

• DataRowState.Added will result in the InsertCommand firing
• DataRowState.Modified will result in the UpdateCommand firing
• DataRowState.Deleted will result in the DeleteCommand firing

• 在任何行返回的结果集的主键对应于数据表中现有的行将用于更新该行，而该行的状态会一直变 DataRowState.Modified ，即使返回的行等同于当前行的 的
• 在任何行返回的结果集的主键不对应于任何现有的行会被用来创建一个新的行，该行的状态会变成 DataRowState.Added
• 在任何行中的数据表不对应于行中返回的结果集将保持在 DataRowState.Unchanged

• Any row in the returned result set whose primary key corresponds to an existing row in the DataTable will be used to update that row, and that row's state will always become DataRowState.Modified, even if the returned row is identical to the current row
• Any row in the returned result set whose primary key doesn't correspond to any existing row will be used to create a new row, and that row's state will become DataRowState.Added
• Any row in the DataTable that doesn't correspond to a row in the returned result set will stay at DataRowState.Unchanged

由于我是正确的这一心理模型，假设我要使用填写（）的通知数据源中删除的行。此外，假设参数的的SelectCommand 不返回整个表。我猜，我有两个选择：

Given that I'm correct with this mental model, suppose I want to use Fill() to notice deleted rows in the data source. Also, suppose that the parameters of the SelectCommand don't return the entire table. I'm guessing that I have two options:

• 找到所有应该已经被更新的行填写（），但仍 DataRowState.Unchanged （依赖于我的未经检验的斜体的假设之上）。这些行已在数据源被删除。
• 清除所有相关行数据表在填写（）;没有再次出现的任何行已经在数据源中被删除。这失去的 DataRowState.Added 的区别和 DataRowState.Modified 是preserved与第一种方法。

• Find all the rows that should've been updated by the Fill() but are still DataRowState.Unchanged (relies on my untested italicized assumption above). These rows have been deleted at the data source.
• Clear all relevant rows from the DataTable before the Fill(); any row that doesn't show up again has been deleted at the data source. This loses the distinction between DataRowState.Added and DataRowState.Modified that is preserved with the first method.

所以，我的问题：

• 是 DataAdapter的正确的，受到的属性值我注意到在上面？
我的上述模型
• 哪些选项应该我去找到删除的行？我想preFER第一位的，但是这依赖于我的假设，所有返回的行会被设置为 DataRowState.Modified ，即使该行是相同的;是一个安全的假设？
• 我要对这个完全错误的？

• Is my above model of the DataAdapter correct, subject to the property values I noted at the top?
• Which option should I go with to find deleted rows? I'd prefer the first one, but that relies on my assumption that all returned rows will be set to DataRowState.Modified even if the row is identical; is that a safe assumption?
• Am I going about this all wrong?

推荐答案

原来，我的假设是错误的，如果由返回的行的SelectCommand 是完全一样的一排已经在数据表，该行仍标记为 DataRowState.Unchanged 。因此，正确的方法是去除行数据表在调用填写（），并确定一排的命运一套新的 DataRowState.Added 行比较行前清单。

Turns out that my assumption is erroneous—if a row returned by the SelectCommand is exactly the same as a row already in the DataTable, that row remains marked as DataRowState.Unchanged. So the proper procedure is removing rows from the DataTable before calling Fill(), and determining the fate of a row by comparing the new set of DataRowState.Added rows to the former list of rows.

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