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Merge/Upsert/AddOrUpdate support #4526

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NickAb opened this issue Feb 10, 2016 · 38 comments
Open

Merge/Upsert/AddOrUpdate support #4526

NickAb opened this issue Feb 10, 2016 · 38 comments

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@NickAb
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@NickAb NickAb commented Feb 10, 2016

In my project I need to insert entity if it does not exist yet, or update it otherwise (somewhat like UPSERT in mongodb). As I understand in SQL it can be accomplished using MERGE, but I was not able to find MERGE in EF Core.

@gdoron
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@gdoron gdoron commented Feb 11, 2016

@NickAb I'm not sure Merge is even applicable to ORMs.
Can you write a little snippet showing how you would have use it?

@rowanmiller rowanmiller changed the title Is there MERGE/UPSERT support in EF7? Merge/Upsert/AddOrUpdate support Feb 12, 2016
@rowanmiller
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@rowanmiller rowanmiller commented Feb 12, 2016

There isn't anything at the moment, though we could potentially do something nice (but not for 1.0.0).

@rowanmiller rowanmiller added this to the Backlog milestone Feb 12, 2016
@NickAb
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@NickAb NickAb commented Feb 13, 2016

@gdoron Actually, I am only interested in merge-as-upsert analog (upsert as in mongo upsert), not full-blown MERGE syntax, so it might look like:

var newFeatureForRegionSetting = new FeatureForRegionSetting();
entity.Region = region;
entity.Feature = feature;
entity.Settings = settings;

dbCtx. FeatureForRegionSettings.Upsert(x => x.region == entity.region && x.feature == entity.feature, newFeatureForRegionSetting);

which will insert newFeatureForRegionSetting if condition is not matched, or update entity if condition is matched.

I can not provide usage example for full-blown merge, as I am not that familiar with other MERGE uses.

@philn5d
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@philn5d philn5d commented Mar 15, 2016

Is it the same feature as this?

@NickAb
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@NickAb NickAb commented Mar 15, 2016

No, I don't think so. As I understand, the issue you are referring to is about "merging disconnected graphs", so it is about interworking of EF change tracking, etc.
What I am referring to is SQL MERGE statement, see docs here https://msdn.microsoft.com/en-us/library/bb510625.aspx

@philn5d
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@philn5d philn5d commented Mar 15, 2016

Ah, I've done this with a home brewed extension method but it needs to get the entity before doing the upsert. Needed to define the key value and didn't support multiple keys. Would be useful to have since it would be more performant.

There's a pattern described https://msdn.microsoft.com/en-us/data/jj592676.aspx
Which is essentially what I wrapped in the extension, would be much better if the framework did this instead. Especially if it can be made to determine if the keys are default or not - without necessarily loading the entity from the data store.

Perhaps it could leverage the MERGE statement as you alluded to. Match on entity keys. I could see folks wanting the results of the MERGE returned which would complicate the operation. The simple case would be useful enough to warrant only Insert or Update with no additional complexity. Also, depends on whether or not the data store supports MERGE if its to be used to implement the feature.

@Ciantic
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@Ciantic Ciantic commented Oct 4, 2016

There is a very handy document in PostgreSQL wiki about UPSERT in various SQL dialects. It may come handy if someone is trying to implement it in the EF.

(In practice it seems there is no agreed way how it should work, especially with unique fields, and would be a messy thing to do in EF because of it)

@yosbeleg89
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@yosbeleg89 yosbeleg89 commented Mar 16, 2017

This is an implementation of MERGE to MSSQL than can give ideas. It is an extension method to EF6.

@PeteX
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@PeteX PeteX commented Apr 30, 2017

I know there are lots of things it would be nice to support, and limited developer time, but it's a shame this one is missing. Apart from this, my code is entirely database-independent, but it's hard to implement upsert without database support.

The usual pattern is that you try to insert, and whether it succeeds or fails, you know the relevant row is in the database. You can therefore pull it out and work with it. There are problems with this approach, though:

  • As far as I can tell, you have to discard the DbContext after the insert fails, because otherwise the next SaveChanges() will retry the insert.
  • EF Core seems to write an unwanted exception message into the log when the insert fails.
  • Failure usually aborts transactions, so the insert attempt and the following update can't be atomic. This creates problems with races where the insert succeeds, but the row gets updated before the following update.
@roji
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@roji roji commented Nov 24, 2017

Just pinging this to make sure it's not totally forgotten. With the seemingly wide support of UPSERT/MERGE across databases, this could be a pretty valuable feature (although of course the specific implementations/variations would have to be investigated (see this comparative doc cited above by @Ciantic)

@ajcvickers
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@ajcvickers ajcvickers commented Nov 27, 2017

@roji Thanks--there's definitely a lot of value in doing this. the comparative doc is very useful--we would have to figure out what to do for SQL Server.

@artiomchi
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@artiomchi artiomchi commented Feb 19, 2018

I liked the idea of an Upsert command for EF Core, so I thought to make a simple extension that could be used in some of the more simple scenarios.

Considering the example above, it could be expressed like this:

dbCtx.Upsert(new FeatureForRegionSetting
  {
    Region = region,
    Feature = feature,
    Settings = settings
  })
  .On(x => new { x.Region, x.Feature })
  .RunAsync();

But it can also handle more interesting scenarios:

DataContext.Upsert(new DailyVisits
  {
    UserID = userID,
    Date = DateTime.UtcNow.Date,
    Visits = 1,
  })
  .On(v => new { v.UserID, v.Date })
  .UpdateColumns(v => new DailyVisits
  {
    Visits = v.Visits + 1,
  })
  .RunAsync();

I've posted the project here: https://github.com/artiomchi/FlexLabs.Upsert
I also described a bit more about it in a blog post. It's a simple extension, and can't be directly merged into EF, but I think the syntax is pretty good, and it might be useful enough for some people :)

@DmitrijOkeanij
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@DmitrijOkeanij DmitrijOkeanij commented Nov 30, 2018

I have situation where Update very needed too.
I ask this situation on StackOverflow, link here.

@Nonary
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@Nonary Nonary commented Feb 21, 2019

Apparently, the update method in Entity functions as an Add or Update by default.
https://docs.microsoft.com/en-us/ef/core/saving/disconnected-entities#saving-single-entities

So this might be able to be closed now?

@vovikdrg
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@vovikdrg vovikdrg commented Feb 21, 2019

@Nonary Add/Update <> Upsert

@Nonary
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@Nonary Nonary commented Feb 21, 2019

@vovikdrg Care to define what's different?
https://en.wiktionary.org/wiki/upsert defines it as a way to update or insert in databases.

@vovikdrg
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@vovikdrg vovikdrg commented Feb 21, 2019

@Nonary I did few comments before. Link you provided has nothing to do with technical stuff if you are asking about words definition and differences probably its wrong thread. If you really care about technical differences of upsert in sql world please check here https://docs.microsoft.com/en-us/sql/t-sql/statements/merge-transact-sql?view=sql-server-2017

@PeteX
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@PeteX PeteX commented Feb 21, 2019

@vovikdrg are you saying that EF doesn't generate the database-specific upsert command? That is important because as I said above, trying to emulate upsert with insert and update tends to lead to odd effects.

@vovikdrg
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@vovikdrg vovikdrg commented Feb 21, 2019

@PeteX EF will generate only update or insert commands which are different from upsert. Also what do you mean about emulate? Upsert is supported almost in all engines.At some point due to complexity maybe it make sense even to be as extension EF.Core.Extension.SqlServer, EF.Core.Extension.MySql

@PeteX
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@PeteX PeteX commented Feb 21, 2019

You don't need to emulate upsert, I was just pointing out that it doesn't work very well if you try!

@artiomchi
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@artiomchi artiomchi commented Feb 21, 2019

@Nonary in the MS docs you linked to, it never tells you that it does an upsert:

The Update method normally marks the entity for update, not insert. However, if the entity has a auto-generated key, and no key value has been set, then the entity is instead automatically marked for insert.

So, it'll either generate an INSERT or an UPDATE sql statement, depending on the state of the entity passed to the Update() method.

@Nonary @vovikdrg @PeteX

At this point in time, there is no native Upsert functionality in Microsoft's EF Core package. If you need upsert support in EF Core, you can either manually construct the correct SQL statement for the DB engine you're using, use an SP.

Another alternative is use the FlexLabs.EntityFrameworkCore.Upsert package that I created. 😄 At the moment, it will generate the SQL statement for SQL Server, MySQL, Postgres and Sqlite, and run it immediately.

I'm continuously working on improving it, and am planning to extend it to use the EF's object state in the future, but even without that - it works quite well, and has been tested in several projects currently in production.

@vovikdrg
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@vovikdrg vovikdrg commented Feb 22, 2019

@PeteX any examples or arguments when it is not working? I did use it many times work like a charm. Maybe my cases were simple or I was doing something "wrong"

@PeteX
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@PeteX PeteX commented Feb 22, 2019

@vovikdrg when what didn't work sorry? I'm not sure if you're talking about EF now, EF as it was when I wrote my first comment, or emulating upsert with INSERT and UPDATE.

In general the problems are races that occur when access to data is contended, so most of the time things will work correctly.

@TanvirArjel
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@TanvirArjel TanvirArjel commented Mar 8, 2019

@ajcvickers Any update about this feature please?

@ajcvickers
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@ajcvickers ajcvickers commented Mar 8, 2019

@TanvirArjel This issue is in the Backlog milestone. This means that it is not going to happen for the 3.0 release. We will re-assess the backlog following the 3.0 release and consider this item at that time. However, keep in mind that there are many other high priority features with which it will be competing for resources.

@vovikdrg
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@vovikdrg vovikdrg commented Mar 8, 2019

0xced added a commit to 0xced/ICanHasDotnetCore that referenced this issue Nov 20, 2019
EF Core does not support upsert out of the box, see dotnet/efcore#4526

But Artiom Chilaru created a NuGet package (FlexLabs.EntityFrameworkCore.Upsert) that handle upsert for PostgreSQL/Sqlite, SqlServer and MySQL.
@yahorsi
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@yahorsi yahorsi commented Jan 16, 2020

Just a small update, tried today to implement repository InsertOrUpdate method, and it is real pain now.

@yahorsi
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@yahorsi yahorsi commented Jan 17, 2020

Referencing the new issue that basically describes the pain you have when you need to insert or update:

#19620

@stijnherreman
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@stijnherreman stijnherreman commented Jan 17, 2020

@yahorsi have you tried the library from #4526 (comment)?

@yahorsi
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@yahorsi yahorsi commented Jan 17, 2020

@yahorsi have you tried the library from #4526 (comment)?

There are definitely libraries that add important but unfortunately missing in the EF things (Bulk, Merge) but IMHO, this should be implemented out of the box in the EF itself.

@onionhammer
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@onionhammer onionhammer commented Apr 15, 2020

I'm continuously working on improving it, and am planning to extend it to use the EF's object state in the future, but even without that - it works quite well, and has been tested in several projects currently in production.

@artiomchi Can you elaborate on a timeline for that?

@nilmas
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@nilmas nilmas commented Apr 25, 2020

A vote for this feature. Could this be implemented in core EF via an additional (preview) NuGet package (Microsoft.EntityFrameworkCore.Upsert) providing functionality for each supported database incrementally if need be. For example, bring support for most popular / most value add databases e.g. SQL Server, PostgreSQL and SQLite.

@ErikEJ
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@ErikEJ ErikEJ commented Apr 25, 2020

@nilmas there are several community packages that provide this functionality already

@nilmas
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@nilmas nilmas commented Apr 25, 2020

@ErikEJ Thanks for replying. I echo the sentiment others have voiced here and elsewhere for upsert to be a good candidate for a core feature of EF. Personally would prefer Microsoft support this core feature rather than a third party.

@onionhammer
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@onionhammer onionhammer commented Apr 25, 2020

@ErikEJ not very effectively. Typically you would want to queue up several changes then call 'db.SaveChanges()', but the change tracking doesn't handle upserts

@sdanyliv
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@sdanyliv sdanyliv commented Jul 20, 2020

For those who is still waiting. Install linq2db.EntityFrameworkCore and follow this documentation link for Merge
Other Insert, Upsert operations are also supported.

@pinoli
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@pinoli pinoli commented Oct 19, 2020

I opened a similar issue, providing (hopefully) specific scenario where this is crucial.
#23044

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