blocks|key|2934870|text|这种情况通常是由以下原因之一造成的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2934871|从数据库视图映射|2934872|实体集|unordered-list-item|2934873|自定义数据库查询|2934874|数据库表没有主键|2934875|2934876|这样做之后，您可能仍然需要在实体框架设计器中进行更新(或者删除实体，然后添加它)，然后才能停止获取错误。|2934877|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Q|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|R|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|F|7|T|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|U|8|@]|9|@]|A|$]]|$1|L|3|M|5|6|7|V|8|@]|9|@]|A|$]]|$1|N|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|O|$]]

It usually happens because one of the following reasons:

<ul>
<li>Entity Set is mapped from Database view</li>
<li>A custom Database query</li>
<li>Database table doesn't have a primary key</li>
</ul>

After doing so, you may still need to update in the Entity Framework designer (or alternatively delete the entity and then add it) before you stop getting the error.

blocks|key|3149312|text|只需向表中添加一个主键即可。就这样。问题解决了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3149313|ALTER+TABLE+<TABLE_NAME>
ADD+CONSTRAINT+<CONSTRAINT_NAME>+PRIMARY+KEY(<COLUMN_NAME>)|code-block|syntax|javascript|3149314|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Just Add a primary key to the table. That's it. Problem solved.

<pre><code>ALTER TABLE &lt;TABLE_NAME&gt;
ADD CONSTRAINT &lt;CONSTRAINT_NAME&gt; PRIMARY KEY(&lt;COLUMN_NAME&gt;)
</code></pre>

blocks|key|3149490|text|这就是我的情况。简单地删除会导致另一个错误。除了最后一篇之外，我遵循了这篇文章的步骤。为了您的方便，我从我遵循的帖子中复制了4个步骤来解决这个问题，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3149491|3149492|右键单击edmx文件，选择打开方式，XML编辑器在edmx中找到实体:StorageModels+element|ordered-list-item|3149493|Remove+DefiningQuery+store:Schema="dbo"+to+Schema="dbo"+(否则，代码将生成错误，说明名称无效)<+code+>G211|offset|length|style|CODE|3149494|3149495|entityMap^0|0|0|0|L|I|17|C|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|P|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|Q|8|@]|9|@]|A|$]]|$1|F|3|G|5|E|7|R|8|@$H|S|I|T|J|K]|$H|U|I|V|J|K]]|9|@]|A|$]]|$1|L|3|-4|5|6|7|W|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|X|8|@]|9|@]|A|$]]]|N|$]]

This is the case for me. Simply removing resulted in another error. I followed the steps of this post except the last one. For your convenience, I copied the 4 steps from the post that I followed to solve the problem as following:

<ol>
<li>Right click on the edmx file, select Open with, XML editor</li>
<li>Locate the entity in the edmx:StorageModels element</li>
<li>Remove the DefiningQuery entirely</li>
<li>Rename the <code>store:Schema="dbo"</code> to <code>Schema="dbo"</code> (otherwise, the code will generate an error saying the name is invalid)</li>
</ol>

blocks|key|254672|text|只需注意，您实体可能具有主键，但是数据库中的表没有主键。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|254673|entityMap^0|6|8|H|A|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

Just note that maybe your Entity have primary key but your table in database doesn't have primary key.

blocks|key|252557|text|更新：我最近在这方面得到了一些好评，所以我想我应该让人们知道我下面给出的建议并不是最好的。自从我最初开始在旧的无键数据库上做实体框架时，我开始意识到到目前为止你能做的最好的事情就是先做反向代码。关于如何做到这一点，有一些很好的文章。只需遵循它们，然后当您想要向其添加键时，使用数据注释来“伪造”键。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|252558|例如，假设我知道我的表Orders，虽然它没有主键，但保证每个客户只有一个订单号。因为这是表中的前两列，所以我将第一个代码类设置为如下所示：|CODE|252559|++++[Key,+Column(Order+=+0)]
++++public+Int32?+OrderNumber+{+get;+set;+}

++++[Key,+Column(Order+=+1)]
++++public+String+Customer+{+get;+set;+}|code-block|syntax|javascript|252560|通过这样做，您基本上是在伪造EF，使其相信有一个由OrderNumber和Customer组成的聚集键。这将允许您在无键的表上执行插入、更新等操作。|252561|如果你不太熟悉先做反向代码，先去找一个关于实体框架代码的很好的教程。然后在Reverse+Code+First上找到一个(这是在现有数据库上先做代码)。然后回到这里，再看看我的关键建议。:)|252562|原始答案|252563|首先:正如其他人所说，最好的选择是向表中添加一个主键。句号。如果你能做到这一点，就不要再读下去了。|252564|但是如果你做不到，或者只是恨你自己，那么有一种方法可以在没有主键的情况下完成。|252565|在我的例子中，我使用的是遗留系统(最初是AS400上的平面文件，移植到Access，然后移植到T-SQL)。所以我得想个办法。这是我的解决方案。下面是我使用Entity+Framework6.0(撰写本文时NuGet上的最新版本)时所做的工作。|252566|252567|在解决方案资源管理器中右键单击.edmx文件。选择“打开方式...”然后选择"XML+(文本)编辑器“。我们将在这里手动编辑自动生成的代码。|ordered-list-item|252568|查找如下所示的行：|252569|252570|将该行下面的<EntitySet+Name="table_name"+EntityType="MyModel.Store.table_name"+store:Type="Tables"+store:Schema="dbo"+store:Name="table_nane">|252571|Remove更改为Schema="whatever"|unordered-list-item|252572|
|252573|Look+store:Name="table_name"，然后找到<DefiningQuery>标记。|252574|252575|将store:Schema="whatever"更改为<DefiningQuery>。它会有一个很大的ol‘select语句。去掉标记，它就是contents.|252576|252577|Now你的代码行应该是这样的：|252578|252579|<EntitySet+Name="table_name"+EntityType="MyModel.Store.table_name"+store:Type="Tables"+Schema="dbo"+/>|252580|We还有一些其他的东西需要改变。查看您的文件并找到以下内容：|252581|252582|<EntityType+Name="table_name">|252583|Nearby您可能会看到一些注释文本，警告您它没有标识主键，因此已经推断了主键，并且定义为只读表/视图。您可以将其保留或删除。我把它删除了。下面的|252584|252585|是<Key>标签。这就是Entity+Framework将用来执行插入/更新/删除的操作。所以要确保你做得对。该标记中的属性(或多个属性)需要指示唯一可识别的行。例如，假设我知道我的表orders，虽然它没有主键，但保证每个客户只有一个订单号。|252586|252587|所以我的看起来像这样：|252588|<EntityType+Name="table_name">
++++++++++++++<Key>
++++++++++++++++<PropertyRef+Name="order_numbers"+/>
++++++++++++++++<PropertyRef+Name="customer_name"+/>
++++++++++++++</Key>|252589|说真的，别做错了。假设即使不应该有重复，但不知何故有两行进入了我的系统，它们具有相同的订单号和客户名称。哇哦！这就是我不使用钥匙所得到的！所以我使用Entity+Framework删除了一个。因为我知道副本是今天放入的唯一订单，所以我这样做：|252590|var+duplicateOrder+=+myModel.orders.First(x+=>+x.order_date+==+DateTime.Today);
myModel.orders.Remove(duplicateOrder);|252591|你猜怎么着？我刚把副本和原件都删除了！这是因为我告诉Entity+Framework，order_number/cutomer_name是我的主键。因此，当我告诉它删除duplicateOrder时，它在后台做的事情是这样的：|252592|DELETE+FROM+orders
WHERE+order_number+=+(duplicateOrder's+order+number)
AND+customer_name+=+(duplicateOrder's+customer+name)|252593|有了警告..。您现在应该可以开始了！|252594|entityMap^0|0|3|0|B|6|0|0|0|0|0|4|0|0|0|0|0|0|0|0|6|3M|0|9|H|0|0|5|N|X|F|0|0|1|N|R|F|0|0|0|0|0|2U|0|0|0|0|U|0|0|0|1|5|2K|6|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|2F|8|@$9|2G|A|2H|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|2I|8|@$9|2J|A|2K|B|H]]|D|@]|E|$]]|$1|I|3|J|5|K|7|2L|8|@]|D|@]|E|$L|M]]|$1|N|3|O|5|6|7|2M|8|@]|D|@]|E|$]]|$1|P|3|Q|5|6|7|2N|8|@]|D|@]|E|$]]|$1|R|3|S|5|6|7|2O|8|@$9|2P|A|2Q|B|C]]|D|@]|E|$]]|$1|T|3|U|5|6|7|2R|8|@]|D|@]|E|$]]|$1|V|3|W|5|6|7|2S|8|@]|D|@]|E|$]]|$1|X|3|Y|5|6|7|2T|8|@]|D|@]|E|$]]|$1|Z|3|-4|5|6|7|2U|8|@]|D|@]|E|$]]|$1|10|3|11|5|12|7|2V|8|@]|D|@]|E|$]]|$1|13|3|14|5|12|7|2W|8|@]|D|@]|E|$]]|$1|15|3|-4|5|6|7|2X|8|@]|D|@]|E|$]]|$1|16|3|17|5|6|7|2Y|8|@$9|2Z|A|30|B|H]]|D|@]|E|$]]|$1|18|3|19|5|1A|7|31|8|@$9|32|A|33|B|H]]|D|@]|E|$]]|$1|1B|3|1C|5|6|7|34|8|@]|D|@]|E|$]]|$1|1D|3|1E|5|1A|7|35|8|@$9|36|A|37|B|H]|$9|38|A|39|B|H]]|D|@]|E|$]]|$1|1F|3|1C|5|6|7|3A|8|@]|D|@]|E|$]]|$1|1G|3|1H|5|1A|7|3B|8|@$9|3C|A|3D|B|H]|$9|3E|A|3F|B|H]]|D|@]|E|$]]|$1|1I|3|1C|5|6|7|3G|8|@]|D|@]|E|$]]|$1|1J|3|1K|5|1A|7|3H|8|@]|D|@]|E|$]]|$1|1L|3|-4|5|6|7|3I|8|@]|D|@]|E|$]]|$1|1M|3|1N|5|6|7|3J|8|@$9|3K|A|3L|B|H]]|D|@]|E|$]]|$1|1O|3|1P|5|1A|7|3M|8|@]|D|@]|E|$]]|$1|1Q|3|-4|5|6|7|3N|8|@]|D|@]|E|$]]|$1|1R|3|1S|5|6|7|3O|8|@$9|3P|A|3Q|B|H]]|D|@]|E|$]]|$1|1T|3|1U|5|1A|7|3R|8|@]|D|@]|E|$]]|$1|1V|3|1C|5|6|7|3S|8|@]|D|@]|E|$]]|$1|1W|3|1X|5|1A|7|3T|8|@$9|3U|A|3V|B|H]|$9|3W|A|3X|B|H]]|D|@]|E|$]]|$1|1Y|3|-4|5|6|7|3Y|8|@]|D|@]|E|$]]|$1|1Z|3|20|5|6|7|3Z|8|@]|D|@]|E|$]]|$1|21|3|22|5|K|7|40|8|@]|D|@]|E|$L|M]]|$1|23|3|24|5|6|7|41|8|@]|D|@]|E|$]]|$1|25|3|26|5|K|7|42|8|@]|D|@]|E|$L|M]]|$1|27|3|28|5|6|7|43|8|@]|D|@]|E|$]]|$1|29|3|2A|5|K|7|44|8|@]|D|@]|E|$L|M]]|$1|2B|3|2C|5|6|7|45|8|@]|D|@]|E|$]]|$1|2D|3|-4|5|6|7|46|8|@]|D|@]|E|$]]]|2E|$]]

UPDATE: I've gotten a few upvotes on this lately, so I figured I'd let people know the advice I give below isn't the best. Since I originally started mucking about with doing Entity Framework on old keyless databases, I've come to realize that the best thing you can do BY FAR is do it by reverse code-first. There are a few good articles out there on how to do this. Just follow them, and then when you want to add a key to it, use data annotations to "fake" the key. 

For instance, let's say I know my table <code>Orders</code>, while it doesn't have a primary key, is assured to only ever have one order number per customer. Since those are the first two columns on the table, I'd set up the code first classes to look like this:

<pre><code> [Key, Column(Order = 0)]
 public Int32? OrderNumber { get; set; }

 [Key, Column(Order = 1)]
 public String Customer { get; set; }
</code></pre>

By doing this, you're basically faked EF into believing that there's a clustered key composed of OrderNumber and Customer. This will allow you to do inserts, updates, etc on your keyless table.

If you're not too familiar with doing reverse Code First, go and find a good tutorial on Entity Framework Code First. Then go find one on Reverse Code First (which is doing Code First with an existing database). Then just come back here and look at my key advice again. :)

Original Answer:

First: as others have said, the best option is to add a primary key to the table. Full stop. If you can do this, read no further.

But if you can't, or just hate yourself, there's a way to do it without the primary key.

In my case, I was working with a legacy system (originally flat files on a AS400 ported to Access and then ported to T-SQL). So I had to find a way. This is my solution. The following worked for me using Entity Framework 6.0 (the latest on NuGet as of this writing).

<ol>
<li>Right-click on your .edmx file in the Solution Explorer. Choose "Open With..." and then select "XML (Text) Editor". We're going to be hand-editing the auto-generated code here.</li>
<li>Look for a line like this: 
<code>&lt;EntitySet Name="table_name" EntityType="MyModel.Store.table_name" store:Type="Tables" store:Schema="dbo" store:Name="table_nane"&gt;</code></li>
<li>Remove <code>store:Name="table_name"</code> from the end.</li>
<li>Change <code>store:Schema="whatever"</code> to <code>Schema="whatever"</code></li>
<li>Look below that line and find the <code>&lt;DefiningQuery&gt;</code> tag. It will have a big ol' select statement in it. Remove the tag and it's contents.</li>
<li>Now your line should look something like this: 
<code>&lt;EntitySet Name="table_name" EntityType="MyModel.Store.table_name" store:Type="Tables" Schema="dbo" /&gt;</code></li>
<li>We have something else to change. Go through your file and find this: 
<code>&lt;EntityType Name="table_name"&gt;</code></li>
<li>Nearby you'll probably see some commented text warning you that it didn't have a primary key identified, so the key has been inferred and the definition is a read-only table/view. You can leave it or delete it. I deleted it.</li>
<li>Below is the <code>&lt;Key&gt;</code> tag. This is what Entity Framework is going to use to do insert/update/deletes. SO MAKE SURE YOU DO THIS RIGHT. The property (or properties) in that tag need to indicate a uniquely identifiable row. For instance, let's say I know my table <code>orders</code>, while it doesn't have a primary key, is assured to only ever have one order number per customer. </li>
</ol>

So mine looks like:

<pre><code>&lt;EntityType Name="table_name"&gt;
 &lt;Key&gt;
 &lt;PropertyRef Name="order_numbers" /&gt;
 &lt;PropertyRef Name="customer_name" /&gt;
 &lt;/Key&gt;
</code></pre>

Seriously, don't do this wrong. Let's say that even though there should never be duplicates, somehow two rows get into my system with the same order number and customer name. Whooops! That's what I get for not using a key! So I use Entity Framework to delete one. Because I know the duplicate is the only order put in today, I do this:

<pre><code>var duplicateOrder = myModel.orders.First(x =&gt; x.order_date == DateTime.Today);
myModel.orders.Remove(duplicateOrder);
</code></pre>

Guess what? I just deleted both the duplicate AND the original! That's because I told Entity Framework that order_number/cutomer_name was my primary key. So when I told it to remove duplicateOrder, what it did in the background was something like:

<pre><code>DELETE FROM orders
WHERE order_number = (duplicateOrder's order number)
AND customer_name = (duplicateOrder's customer name)
</code></pre>

And with that warning... you should now be good to go!

blocks|key|250836|text|如果数据模型过期，也会发生这种情况。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|250837|希望这能让其他人免于受挫:)|250838|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

This can also happen if data model is out of date.

Hopefully this will save someone else frustration :)

blocks|key|2934920|text|我收到了相同的错误消息，但在我的场景中，我试图使用PJT+(Pure+Join+Table)更新从多对多关系派生的实体。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2934921|通过阅读其他帖子，我认为我可以通过向join表添加一个额外的PK字段来修复它……但是，如果您将PK列添加到连接表中，它将不再是PJT，并且您将失去所有实体框架的优势，如实体之间的自动关系映射。|2934922|因此，在我的示例中，解决方案是修改DB上的join表，以创建包含两个外部ID列的PK。|2934923|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

I was getting the same error message, but in my scenario I was trying to update entities derived from a many-to-many relationship using a PJT (Pure Join Table).

From reading the other posts, I thought I could fix it by adding an additional PK field to the join table... However, if you add a PK column to a join table, it is no longer a PJT and you lose all of the entity framework advantages like the automatic relationship mapping between the entities.

So the solution in my case was to alter the join table on the DB to make a PK that includes BOTH of the foreign ID columns.

blocks|key|2935101|text|如果您的表没有主键，则可能会发生错误，在这种情况下，表是“只读”的，并且db.SaveChanges+()命令总是会出错。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2935102|entityMap^0|10|H|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

The error may have occurred if your table doesn't have a primary key, in this case the table is &quot;read only&quot;, and the <code>db.SaveChanges ()</code> command will always error.

blocks|key|2935162|text|设置主键，然后保存表并刷新，然后转到Model.edmx删除表并再次获取。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2935163|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Set Primary Key then save Table and Refresh then go to Model.edmx delete Table and get again .

blocks|key|3149432|text|所以是真的，只需添加一个主键|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|3149433|注意:请确保当您从指向right数据库的数据库更新EF图时，在我的示例中，连接字符串指向本地DB，而不是最新的Dev+DB，我知道这是一个学生错误，但我之所以要发布这篇文章，是因为如果您确信已经添加了主键，但仍然收到相同的错误，这可能会非常令人沮丧|3149434|entityMap^0|0|E|0|B|5|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|P|8|@]|D|@]|E|$]]]|I|$]]

so its true, just add a primary key

Note: be sure that when you're updating your EF diagram from the database that you're pointing to the right database, in my case the connection string was pointing to a local DB instead of the up-to-date Dev DB, schoolboy error i know, but I wanted to post this because it can be very frustrating if you're convinced you've added the primary key and you're still getting the same error

blocks|key|2935120|text|我也有同样的问题。正如这个线程所说，我的表没有PK，所以我设置了PK并运行了代码。但不幸的是，错误又来了。我接下来做的是，删除DB连接(删除解决方案资源管理器的Model文件夹中的.edmx文件)并重新创建它。错误在那之后消失了。感谢大家分享你们的经验。它节省了很多时间。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2935121|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I had the same issue. As this thread said, My table didn't have a PK, so I set the PK and ran the code. But unfortunately error came again. What I did next was, deleted the DB connection (delete .edmx file in Model folder of Solution Explorer) and recreated it. Error gone after that. Thanks everyone for sharing your experiences. It save lots of time.

blocks|key|251007|text|这不是一个新的答案，但可以帮助那些不确定如何为他们的表设置主键的人。在新的查询中使用它并运行。这会将UniqueID列设置为主键。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|251008|USE+[YourDatabaseName]
GO

Alter+table++[dbo].[YourTableNname]
Add+Constraint+PK_YourTableName_UniqueID+Primary+Key+Clustered+(UniqueID);
GO|code-block|syntax|javascript|251009|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is not a new answer but will help somebody who's not sure how to set primary key for their table. Use this in a new query and run. This will set UniqueID column as primary key.

<pre><code>USE [YourDatabaseName]
GO

Alter table [dbo].[YourTableNname]
Add Constraint PK_YourTableName_UniqueID Primary Key Clustered (UniqueID);
GO
</code></pre>

blocks|key|2935269|text|​|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2935270|📷|atomic|offset|length|2935271|2935272|在我的例子中，忘记定义表的主键。因此，分配如图所示，并从.edmx文件的"Update+model+from+Database“中刷新您的表。希望它能有所帮助！|2935273|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/334f228161464930eda71ce814780c4e.png|imageAlt^0|0|0|1|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@$E|U|F|V|1|W]]|A|$]]|$1|G|3|4|5|6|7|X|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|Y|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|Q|R|-4]]]]

<a href="https://i.stack.imgur.com/mcxpT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mcxpT.png" alt="enter image description here"></a>

In my case, forgot to define Primary Key to Table. So assign like shown in Picture and Refresh your table from "Update model from Database" from .edmx file.
Hope it will help !!!

blocks|key|2935085|text|我遇到这个问题是因为我从一个已有的数据库中生成了我的EDMX+(由其他人设计，我在这里使用的术语是“设计的”)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2935086|原来桌子上根本没有钥匙。EF正在生成具有许多多个关键点的模型。我必须在SQL中添加一个主键到db表中，然后在VS中更新我的模型。|2935087|帮我修好了。|2935088|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

I was getting this issue because i was generating my EDMX from an existing database (designed by somebody else, and i use the term 'designed' loosely here).

Turns out the table had no keys whatsoever. EF was generating the model with many multiple keys. I had to go add a primary key to the db table in SQL and then updated my model in VS. 

That fixed it for me.

blocks|key|3149522|text|添加主键对我也有效！|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3149523|完成后，下面是如何在不删除数据模型的情况下更新数据模型-|3149524|右键单击edmx实体设计器页面，然后单击“从数据库更新模型”。|3149525|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

Adding the primary key worked for me too !

Once that is done, here's how to update the data model without deleting it -

Right click on the edmx Entity designer page and 'Update Model from Database'.

blocks|key|254804|text|我遇到了完全相同的问题，不幸的是，添加主键并不能解决问题。下面是我如何解决我的问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|254805|为了确保表中有一个文件，我更改了我的表并添加了一个主key.|254806|Delete+the+ADO.NET+Entity+Data+Model+(edmx文件)，我使用它来映射和连接我的database.|unordered-list-item|offset|length|style|CODE|254807|
|254808|Add+again+a+new+file+of+ADO.NET+Entity+Data+Model，以连接到我的数据库以及映射我的模型properties.|254809|254810|Clean+and+rebuild+the+solution.+|254811|254812|问题解决了。|254813|entityMap^0|0|0|0|10|0|0|0|1D|0|0|0|V|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Y|8|@$G|Z|H|10|I|J]]|9|@]|A|$]]|$1|K|3|L|5|6|7|11|8|@]|9|@]|A|$]]|$1|M|3|N|5|F|7|12|8|@$G|13|H|14|I|J]]|9|@]|A|$]]|$1|O|3|L|5|6|7|15|8|@]|9|@]|A|$]]|$1|P|3|Q|5|F|7|16|8|@$G|17|H|18|I|J]]|9|@]|A|$]]|$1|R|3|-4|5|6|7|19|8|@]|9|@]|A|$]]|$1|S|3|T|5|6|7|1A|8|@]|9|@]|A|$]]|$1|U|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|V|$]]

I had the exact same problem, unfortunately, adding the primary key doesn't solve the issue. So here's how I solve mine:

<ol>
<li>Make sure you have a <code>primary key</code> on the table so I alter my table and add a primary key.</li>
<li><code>Delete the ADO.NET Entity Data Model</code> (edmx file) where I use to map and connect with my database.</li>
<li><code>Add again a new file of ADO.NET Entity Data Model</code> to connect with my database and for mapping my model properties.</li>
<li><code>Clean and rebuild the solution.</code> </li>
</ol>

Problem solved.

blocks|key|3149544|text|只需向表中添加一个主键，然后重新创建EF|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3149545|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

just add a primary key to your table and then recreate your EF

blocks|key|255969|text|我只需要从模型中删除表，并再次更新模型，将表重新带回来。我猜主键是在表被拉到模型中之后创建的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|255970|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I just had to remove the table from the model and update the model again bringing the table back. I guess the primary key was created after the table was pulled into the model.

blocks|key|254834|text|出现这个问题是因为我删除了表主键上的索引，并将其替换为表中其他字段的索引。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|254835|删除主键索引并刷新edmx后，插入停止工作。|254836|我将表刷新到较旧的版本，刷新了edmx，一切都正常了。|254837|我应该注意，当我打开EDMX来解决这个问题，检查是否定义了主键时，有。所以上面的建议对我都没有帮助。但是刷新主键上的索引似乎是可行的。|254838|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

I had this issue come up and believe it was caused because I had deleted the Index on my tables primary key and replaced it with an index on some of the other fields in the table.

After I deleted the primary key index and refreshed the edmx, inserts stopped working. 

I refreshed the table to the older version, refreshed the edmx and everything works again. 

I should note that when I opened the EDMX to troubleshoot this issue, checking to see if there was a primary key defined, there was. So none of the above suggestions were helping me. But refreshing the index on the primary key seemed to work.

blocks|key|3149598|text|在XML编辑器中打开.edmx文件，然后从标签中删除标签，并将store:Schema="dbo“更改为Schema="dbo”，然后重新构建解决方案，错误将立即解决，您将能够保存数据。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3149599|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Open Your .edmx file in XML editor and then remove tag from Tag and also change store:Schema="dbo" to Schema="dbo" and rebuild the solution now error will resolve and you will be able to save the data.

blocks|key|2935233|text|我发现更新.edmx文件的原始答案在我的情况下效果最好。每次从数据库更新模型时，我都会对模型进行修改，这让我很不高兴。这就是为什么我写了一个额外的文本模板文件，它会在模型更改后自动调用-就像新生成的实体一样。我在这里发表了这条评论。要使其正常工作，请确保将其命名为{型号名称}.something.tt，并将其存储在与.edmx文件夹相同的文件夹中。我将其命名为{型号名称}.NonPkTables.tt。由于第二行中的文件扩展名定义无效，因此它不会单独生成文件。请随意使用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2935234|<#@+template+language="C#"+debug="false"+hostspecific="true"#>
<#@+output+extension="/"+#>
<#@+assembly+name="System.Core"+#>
<#@+assembly+name="System.Data"+#>
<#@+assembly+name="System.Windows.Forms"+#>
<#@+assembly+name="System.Xml"+#>
<#@+assembly+name="System.Xml.Linq"#>
<#@+assembly+name="%25VS120COMNTOOLS%25..\IDE\EntityFramework.dll"+#>
<#@+assembly+name="%25VS120COMNTOOLS%25..\IDE\Microsoft.Data.Entity.Design.dll"+#>
<#@+import+namespace="System"+#>
<#@+import+namespace="System.Windows.Forms"+#>
<#@+import+namespace="System.Linq"+#>
<#@+import+namespace="System.IO"+#>
<#@+import+namespace="System.Collections.Generic"+#>
<#@+import+namespace="System.Xml"+#>
<#@+import+namespace="System.Xml.Linq"+#>
<#@+import+namespace="System.Globalization"+#>
<#@+import+namespace="System.Reflection"+#>
<#@+import+namespace="System.Data.Entity.Core.Metadata.Edm"+#>
<#@+import+namespace="System.Data.Entity.Core.Mapping"+#>
<#@+import+namespace="System.CodeDom"+#>
<#@+import+namespace="System.CodeDom.Compiler"+#>
<#@+import+namespace="Microsoft.CSharp"#>
<#@+import+namespace="System.Text"#>
<#@+import+namespace="System.Diagnostics"+#>

<#
++++string+modelFileName=+this.Host.TemplateFile.Split('.')[0]+%2B+".edmx";
++++string+edmxPath+=+this.Host.ResolvePath(+modelFileName+);

++++//+MessageBox.Show(+this.Host.TemplateFile+%2B+"+applied."+);
++++var+modelDoc+=+XDocument.Load(edmxPath);
++++var+root+=+modelDoc.Root;
++++XNamespace+nsEdmx+=+@"http://schemas.microsoft.com/ado/2009/11/edmx";
++++XNamespace+ns+=+@"http://schemas.microsoft.com/ado/2009/11/edm/ssdl";

++++var+runtime+=+root.Elements(nsEdmx+%2B+"Runtime").First();
++++var+storageModels+=+runtime.Elements(nsEdmx+%2B+"StorageModels").First();
++++XNamespace+nsStore+=+@"http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator";

++++var+schema+=+storageModels.Elements(ns+%2B+"Schema").First();
++++XNamespace+nsCustomAnnotation+=+@"http://schemas.microsoft.com/ado/2013/11/edm/customannotation";

++++var+entityTypes+=+schema.Nodes().OfType<XComment>().Where(c+=>+c.Value.Contains("warning+6002:+The+table/view"));
++++bool+changed+=+false;

++++foreach+(var+node+in+entityTypes)
++++{
++++++++var+element+=+node.ElementsAfterSelf().First();
++++++++string+entityName+=+element.Attribute("Name").Value;

++++++++//+Find+EntitySet+in+EntityContainer.
++++++++var+entityContainer+=+schema.Elements(ns+%2B+"EntityContainer").First();
++++++++var+entitySet+=+entityContainer.Elements(ns+%2B+"EntitySet").First(s+=>+s.Attribute("Name").Value+==+entityName);

++++++++//+Change+"store:Schema"+attribute+to+"Schema"+attribute.
++++++++var+attribute+=+entitySet.Attribute(nsStore+%2B+"Schema");

++++++++if+(attribute+!=+null)
++++++++{
++++++++++++string+schemaName+=+entitySet.Attribute(nsStore+%2B+"Schema").Value;
++++++++++++entitySet.Attribute(nsStore+%2B+"Schema").Remove();
++++++++++++entitySet.Add(new+XAttribute("Schema",+schemaName));
++++++++++++changed+%7C=+true;
++++++++}

++++++++//+Remove+the+DefiningQuery+element.
++++++++var+definingQuery+=+entitySet.Element(ns+%2B+"DefiningQuery");

++++++++if+(definingQuery+!=+null)
++++++++{
++++++++++++definingQuery.Remove();
++++++++++++changed+%7C=+true;++++++++
++++++++++++Debug.WriteLine(string.Format("Removed+defining+query+of+EntitySet+{0}.",+entityName));
++++++++}
++++}

++++if+(changed)
++++++++modelDoc.Save(edmxPath);
#>|code-block|syntax|javascript|2935235|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I found the original answer of updating the .edmx file work best in my situation. I just wasn't too happy about altering the model every time it was updated from the database. That's why I wrote an additional Text Template file, that is automaticaly invoked when after the model has changed - just like the entities are newly generated. I post it here in this comment.
To make it work, make sure you name it like {model name}.something.tt, and store it in the same folder as your .edmx folder. I named it {model name}.NonPkTables.tt. It does not generate a file on its own due to the invalid file extension definition in the second line. Feel free to use.

<pre><code>&lt;#@ template language="C#" debug="false" hostspecific="true"#&gt;
&lt;#@ output extension="/" #&gt;
&lt;#@ assembly name="System.Core" #&gt;
&lt;#@ assembly name="System.Data" #&gt;
&lt;#@ assembly name="System.Windows.Forms" #&gt;
&lt;#@ assembly name="System.Xml" #&gt;
&lt;#@ assembly name="System.Xml.Linq"#&gt;
&lt;#@ assembly name="%VS120COMNTOOLS%..\IDE\EntityFramework.dll" #&gt;
&lt;#@ assembly name="%VS120COMNTOOLS%..\IDE\Microsoft.Data.Entity.Design.dll" #&gt;
&lt;#@ import namespace="System" #&gt;
&lt;#@ import namespace="System.Windows.Forms" #&gt;
&lt;#@ import namespace="System.Linq" #&gt;
&lt;#@ import namespace="System.IO" #&gt;
&lt;#@ import namespace="System.Collections.Generic" #&gt;
&lt;#@ import namespace="System.Xml" #&gt;
&lt;#@ import namespace="System.Xml.Linq" #&gt;
&lt;#@ import namespace="System.Globalization" #&gt;
&lt;#@ import namespace="System.Reflection" #&gt;
&lt;#@ import namespace="System.Data.Entity.Core.Metadata.Edm" #&gt;
&lt;#@ import namespace="System.Data.Entity.Core.Mapping" #&gt;
&lt;#@ import namespace="System.CodeDom" #&gt;
&lt;#@ import namespace="System.CodeDom.Compiler" #&gt;
&lt;#@ import namespace="Microsoft.CSharp"#&gt;
&lt;#@ import namespace="System.Text"#&gt;
&lt;#@ import namespace="System.Diagnostics" #&gt;

&lt;#
 string modelFileName= this.Host.TemplateFile.Split('.')[0] + ".edmx";
 string edmxPath = this.Host.ResolvePath( modelFileName );

 // MessageBox.Show( this.Host.TemplateFile + " applied." );
 var modelDoc = XDocument.Load(edmxPath);
 var root = modelDoc.Root;
 XNamespace nsEdmx = @"http://schemas.microsoft.com/ado/2009/11/edmx";
 XNamespace ns = @"http://schemas.microsoft.com/ado/2009/11/edm/ssdl";

 var runtime = root.Elements(nsEdmx + "Runtime").First();
 var storageModels = runtime.Elements(nsEdmx + "StorageModels").First();
 XNamespace nsStore = @"http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator";

 var schema = storageModels.Elements(ns + "Schema").First();
 XNamespace nsCustomAnnotation = @"http://schemas.microsoft.com/ado/2013/11/edm/customannotation";

 var entityTypes = schema.Nodes().OfType&lt;XComment&gt;().Where(c =&gt; c.Value.Contains("warning 6002: The table/view"));
 bool changed = false;

 foreach (var node in entityTypes)
 {
 var element = node.ElementsAfterSelf().First();
 string entityName = element.Attribute("Name").Value;

 // Find EntitySet in EntityContainer.
 var entityContainer = schema.Elements(ns + "EntityContainer").First();
 var entitySet = entityContainer.Elements(ns + "EntitySet").First(s =&gt; s.Attribute("Name").Value == entityName);

 // Change "store:Schema" attribute to "Schema" attribute.
 var attribute = entitySet.Attribute(nsStore + "Schema");

 if (attribute != null)
 {
 string schemaName = entitySet.Attribute(nsStore + "Schema").Value;
 entitySet.Attribute(nsStore + "Schema").Remove();
 entitySet.Add(new XAttribute("Schema", schemaName));
 changed |= true;
 }

 // Remove the DefiningQuery element.
 var definingQuery = entitySet.Element(ns + "DefiningQuery");

 if (definingQuery != null)
 {
 definingQuery.Remove();
 changed |= true; 
 Debug.WriteLine(string.Format("Removed defining query of EntitySet {0}.", entityName));
 }
 }

 if (changed)
 modelDoc.Save(edmxPath);
#&gt;
</code></pre>

blocks|key|2935340|text|我通过删除并重新构建EF项目及其所有类来修复它。详情见下文：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2935341|我在这个问题上反复了一个小时，然后删除了包含错误的EF项目，保存了我所有的自定义代码，然后重新构建了整个代码。由于这只是生成一个新的EF图及其内部代码的问题，这个修复问题的过程花费了大约10分钟。|2935342|问题是，我怀疑，数据库优先生成EF类和属性的方法在两到三次“更新”之后变得有点奇怪。基本上，我在代码行为中发现了一个问题，并修复了数据库表属性，然后多次更新了EF图。然后我试着摆弄代码，但不起作用。|2935343|从头开始工作。|2935344|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

I fixed it by just deleting and rebuilding the EF project and all its classes. See details below:
I went round and round on this one for an hour, then deleted the EF project containing the error, saving out all my custom code, then rebuilding the whole thing. Since it was just a matter of generating a new EF diagram and its inner code, this process of fixing the problem took about 10 minutes.
The problem, I suspect, is that the database-first method for generating EF classes and properties gets a little weird after two or three &quot;updates&quot;. Basically, I found a problem in the code behavior, went and fixed the database table properties, and then updated the EF diagram one time too many. Then I tried fiddling with the code, which didn't work.
Starting over worked.

I am using Entity Framework 1 with .net 3.5.

I am doing something simple like this:

<pre><code>var roomDetails = context.Rooms.ToList();

foreach (var room in roomDetails)
{ 
 room.LastUpdated = DateTime.Now;
}
</code></pre>

I am getting this error when I try to do:

<pre><code> context.SaveChanges();
</code></pre>

I get the error:

<blockquote>
 Unable to update the EntitySet - because it has a DefiningQuery and no &lt;UpdateFunction&gt; element exists in the &lt;ModificationFunctionMapping&gt; element to support the current operation.
</blockquote>

I am doing lots of updates on the context and not having any issues, it's only when I try to update this particular entity.

All my searching shows up the same thing, that there is no primary key declared on the entity that I'm trying to update. But alas, I do have a Primary key declared...

Unable to update the EntitySet - because it has a DefiningQuery and no <UpdateFunction> element exist

数据库

Windows

我正在使用Entity Framework1和.net 3.5。我正在做一些简单的事情，像这样：var roomDetails = context.Rooms.ToList();foreach (var room in roomDetails){           room.LastUpdated = DateTime.Now;}当我尝试这样做时，我得到了这个错误： context.SaveCh

问无法更新EntitySet -因为它具有DefiningQuery且不存在<UpdateFunction>元素
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问无法更新EntitySet -因为它具有DefiningQuery且不存在<UpdateFunction>元素
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