I have an Oracle database that has all its tables and columns in all Upper-Case.
For example table STUDENT has FIRSTNAME,LASTNAME and DATEOFBIRTH
when i generate classes using EF Database First approach, i get all classes and names in Upper-Case as well.
answer here
How to force pascal case with Oracle's Entity Framework support?
did not helped as it only generates names with only First letter in upper case instead of FirstName or LastName.
I thought of doing it manually. Is there a way i can write something in OnModelCreating so that every time i generate edmx i get the names right?
If i change name after generation its going to override next time i update it from database.
ReSharper may be able help with this, though I have not used Re# in a while or the naming convention feature. (see: https://www.jetbrains.com/help/resharper/Inspect_the_Whole_Solution_for_Naming_Style_Compliance.html) Tell it you want UpperCamelCase and run it across the generated code. There may be other plug-ins available with this capability.
EF isn't going to do it as I doubt they'd be trying to determine word boundaries for naming. howwillitknowhowmanywordsareinhere? :)
Related
I am in the process of migrating the database from SQL to postgres. The application code is using Entity framework 6. I am facing issues with case sensitivity as postgres stores table, column names in lower case unless using double quotes.
The data present in postgres is in lower case (table and column names). With Entity framework 6, I am facing issues with it not been able to find the table or column names as it is trying to use Pascal case.
I have searched and found few links:
Case insensitive name of tables and properties in Entity Framework 7
The above is for EF7 and most of the solutions doesn't work with EF6. I also tried to look for options in OnModelCreating but didn't find anything useful with DbModelBuilder as this is the object being passed to OnModelCreating.
I don't want to change all the entities to include the table and column names. I am wondering if one of you could help on this.
Appreciate any help.
Have a look at defining some custom Conventions or using the ModelBuilder to standardize case names. (see: https://learn.microsoft.com/en-us/ef/ef6/modeling/code-first/conventions/custom) The other options are to define table and column names via the attributes/configuraion.
Personally, with PostgreSQL I elected to use PascalCase for my table/column names. It meant my manual querying needed to use quotes, but frankly I'm more comfortable looking at naming conventions that way in databases.
I have been reading up on code first approach with entity framework. Unfortunately I can't find much documentation than what relates to EF4 on this. But the docs I have read (scott gu's blog on EF4) indicate that I don't need mappings.
So I generated a code files from an existing database using the EF6 Power Tools this generates all my model classes and a mappings folder. Automatically I looked at the mappings files in there which are using the Fluent API (I think this is correct) and describe details about the tables.
Now reading this makes sense that it possibly wouldn't know the Primary Key, Required Properties, Relationships but the thing I don't get is the Property to Column Mappings from the blog post these were not needed so why do I need them?
I can understand needing them if a column name can't be represented in code but my naming conventions don't allow this.
My main reason for asking is a maintainability question I would rather only have code for a particular property in one place and these lines this.Property(t => t.ID).HasColumnName("ID"); seem redundant to me.
Any one with any helpful links on EF6 code first approach would be appreciated as well google is failing :)
You certainly don't need property mappings if you're satisfied with the default column names and so on. You may need them for things like setting the order of columns in a compound primary key, or specifying that a property contains a database-generated value (like an identity/autoincrement column), but even then you can leave the column names out of it and stick with the defaults.
Column mappings do have some uses, but I'm not sure any of them are relevant to your situation:
You can map your entities to an existing database without having to mimic the column names, which may not follow standard .NET naming conventions.
Similarly, you can follow different naming conventions in your code vs. in your database. For example, where I work, database columns are usually expected to be camelCase, not PascalCase.
They allow you to change the names of your properties at a later date without having to recreate/migrate your database.
If none of those apply to you, then yeah, I think you're probably fine without them.
EF use conventions to do a lot. Once you know and feel comfortable with conventions you can declare classes and things just work.
Code first conventions
I am using EF Code First in a project with an existing Database, all works well and so far I have been creating the class for each table manually (as they have been very small) but getting to the larger tables I can only assume there must be a better way to 'import' or 'convert' the tables fields into a class somehow. Had a search around and can't really find what I'm looking for.
To clarify I want to keep it Code First.
EF Power Tools contains reverse engineer feature for this purpose.
If we've been using an Entity Framework 4 model for some time, and we eventually want to switch the underlying database to a different vendor's product (say, from SQL Server to MySQL), is it simple to adjust the table and column mappings in the entity model without needing to update any of the entity class code?
We're trying to design code that is as database agnostic as possible, so I'd like to know in advance how much trouble we're in for if we ever switch our databases around. Ideally, we'd like to not have to touch our applications that use our entity classes. I can't seem to find any way in the entity designer or XML editor to adjust the underlying database column names without it giving me an error.
(I can, however, edit the entity's property names in the designer while leaving the database column names alone, but that's the opposite of what I need.)
Thanks!
EDMX is not database agnostic. SSDL part of EDMX is tightly coupled with database server (in case of MSSQL even with its version). You need separate SSDL for each supported database server.
I don't understand how changing column names relates to database agnostic model. Reverse is true! If you need your database to have different column names for different server products you need separate mapping for each of them!
Changing column names when using model first is possible only if you modify T4 template used for generating database creation SQL script. But every time you create that script designer will delete whole your storage description (SSDL) and mapping (MSL) and replace them with a new one.
The easiest way to have database agnostic code is using code first but even then you can have problems with some type and feature inconsistency among servers.
If you want database agnostic ORM you should probably check NHibernate.
I have a database that I wish to build an EF model from, however I do not want to include certain columns from the database as the columns concerned are maintained exclusively on the server and should not be manipulated by any application.
Both of the columns are DateTime (if this makes any difference), one of the columns is nullable and is maintained by a trigger on updates and the other is not nullable and set using a default value in the table definition.
I guess I am looking for something like the "Server Generated" option in Linq2Sql; but I cannot find such an option.
Can anybody tell me how to work around this?
Caveat:
I have been trying to introduce business object modelling at my place of work for some years and it has always been rejected because of the amount of additional code that has to be hand-cranked. EF is currently being seen as a viable solution because of the designer and code generation therefore any option that involves hand-cranking the XML will only turn the rest of my colleagues away from EF. I am therefore looking for something that can be done either using the designer or using code.
EDIT:
I guess that what I am looking for here is either...
(a) a way to create the model without EF referencing the columns in the store (ssdl) and therefore not looking to manipulate it in any way
(b) a way to programatically set the "StoreGeneratedPattern" attribute against the property when I create the ObjectContext (the easy answer is to manually manipulate this in the .ssdl, but this would then be overwritten if I refreshed the model from the database and I cannot go down the route where the .csdl, .msl & .ssdl are hand-cranked).
Can you do this with the Entity Framework? Yes; it's easy. Can you do this with the Entity Framework designer? Unfortunately, that is much harder.
The problem you're having is that the column exists in the storage schema (SSDL) in your EDMX. Removing the column with the GUI designer simply removes it from the client schema, not the mapping or the storage schema. However, it's simple enough to go into the EDMX and remove it. Having done that, you can also remove it from the mapping in the client schema portions of the EDMX, and the entity framework will longer complain that it is unmapped.
Problem solved, right?
Well, no. When you use the GUI designer to update the EDMX from the database, the storage schema is thrown away and re-generated. So your column will come back. As far as I know, there is no way to tell the GUI designer to never map a particular column. So you will have to re-do this every time you update with the GUI designer. Fortunately, the EDMX is XML, so you can do this with a XML transform, LINQ, or the XML tool of your choice.
Can you not create a view with the columns you need and import it through entity function wizard and map it to your entities?
You could modify the text template to ignore these columns when generating your entity classes. For example if you added "IGNORE" to the documentation summary, you could modify the template to ignore them by replacing;
Dim simpleProperties as IEnumerable(Of EdmProperty) = typeMapper.GetSimpleProperties(entity)
with;
Dim simpleProperties as IEnumerable(Of EdmProperty) = typeMapper.GetSimpleProperties(entity).Where(Function(p) p.Documentation is nothing orelse p.Documentation.Summary.IndexOf("IGNORE")<0)
Right click on the field in the graphical representation and choose delete. Ive found that sometimes you will get errors when you make a lot of changes to the modeling at once and start to lose track of your changes. Your best bet might be to rebuild the EF generated model.
Keep in mind that when you "update from the database", that old fields on the generated models will not be removed, you will have to remove them manually. For example if you renamed DateField1 to DateField2 in your database, and then you "Update Model from Database", you will now see both DateField1 and DateField2 on the resultant model. This can be a cause of errors.
Do you not want the column to appear in the model at all?
Try selecting the column in the Designer view and hitting the delete key.
Edit
You could make the setter for the property private. Then your app won't be able to modify the value.
Timestamp is a different data type than DateTime. Timestamp seems to be recognized as an attribute the engine manages, much like an identity attribute. You can't "update" a timestamp attribute. Hence, the EDM can manage it correctly (just as it does an identity).
In EDMX designer, select the property and set StoreGeneratedPattern to Computed.