I'm using OrmLite with both SqlServer, Oracle and PostgreSQL dialects.
I want to use GUIDs as primary keys and have a simple object, using the AutoId attribute:
public class MyObject
{
[AutoId]
public Guid Id { get; set; }
[Required]
public string Name { get; set; }
...
All goes well with SqlServer and PostgreSQL dialetcs, but with Oracle I get an initial GUID with all zeros in the db, and a subsequent INSERT violates the unique key constraint of my primary key. How can this be accomplished db agnostic so it also works with Oracle?
Based on the source code I'm looking at, it doesn't appear to properly generate GUIDs for anything that's not SQL Server or PostgreSQL, regardless of what the documentation actually says on the README. Relevant code links below:
SQL Server
PostgreSQL
Base Dialect Provider
The best alternative I can provide here is to override the OracleOrmLiteDialectProvider. Specifically, I would override the GetAutoIdDefaultValue method to return "SYS_GUID()" if the field type is a GUID. Sample code below...
public OracleNewGuidOrmLiteDialectProvider : OracleOrmLiteDialectProvider
{
public static OracleNewGuidOrmLiteDialectProvider Instance = new OracleNewGuidOrmLiteDialectProvider();
public string AutoIdGuidFunction { get; set; } = "SYS_GUID()";
public override string GetAutoIdDefaultValue(FieldDefinition fieldDef)
{
return fieldDef.FieldType == typeof(Guid)
? AutoIdGuidFunction
: null;
}
}
To match the rest of the provider implementations, I would recommend creating a OracleNewGuidDialect class, like below...
public static class OracleNewGuidDialect
{
public static IOrmLiteDialectProvider Provider => OracleNewGuidOrmLiteDialectProvider.Instance;
}
Then you would set the provider when you instantiate your OrmLiteConnectionFactory to OracleNewGuidOrmLiteDialectProvider.Instance, similar to below...
var dbFactory = new OrmLiteConnectionFactory(oracleConnectionString, OracleNewGuidDialect.Provider);
This isn't the best solution, but the pluggable nature of ServiceStack ORMLite allows you to control everything to the extent that you need. Hope this helps. Also, quick caveat--I didn't fully bake this solution, so you may need to tweak it, but based on the other implementations of the providers, it seems straightforward.
Related
Does any one have a working example of how to added audit models to an existing project, for Audit.Net.
It is one fantastic component to use, and up until now, my team and I have gotten by with the standard JSON files, however, we'd like to migrate our current solution to our Xamarin application, and would like to store the auditing in the local SQLite database on the device.
However, the documentation for this project is somewhat lacking and there is no concise examples of how to get custom auditing working with Entity Framework.
We have worked through the MD files on the github repo, but we still cannot get auditing to work.
Another question, similar to this has been asked HERE, but there is no definitive example of what the Audit_{entity} table should look like, what fields it MUST contain, and how to set up relationships for it.
We tried to reverse engineer the JSON files into a relational structure, but at the time of asking this question, we have not gotten any auditing to write to the SQLite database.
Sorry about the documentation not helping too much, hope I (or anybody) can provide better documentation in the future.
I am assuming you are using EntityFramework to map your entities
to a SQLite database, and you want to use the EF data
provider
to store the audits events in the same database, in Audit_{entity} tables.
There is no constraint on the schema you want to use for your Audit_{entity} tables, as long as you have a one-to-one relation between your {entity} table and its Audit_{entity} table. Then the mapping can be configured on several ways.
The recommendation for the Audit_{entity} tables is to have the same columns as the audited {entity} table, with any common additional column needed, like a User and a Date defined on an Interface.
So, if all your Audit_{entity} tables has the same columns/properties as its {entity}, and you added some common columns (defined on an interface), the configuration can be set like this:
public class User
{
public int Id { get; set; }
public string Name { get; set; }
}
public class Audit_User : IAudit
{
public int Id { get; set; }
public string Name { get; set; }
// IAudit members:
public string AuditUser { get; set; }
public datetime AuditDate { get; set; }
public string Action { get; set } // "Insert", "Update" or "Delete"
}
Audit.Core.Configuration.Setup()
.UseEntityFramework(x => x
.AuditTypeNameMapper(typeName => "Audit_" + typeName)
.AuditEntityAction<IAudit>((ev, ent, auditEntity) =>
{
auditEntity.AuditDate = DateTime.UtcNow;
auditEntity.AuditUser = evt.Environment.UserName;
auditEntity.AuditAction = ent.Action;
});
Note the interface is not mandatory, but using it makes the configuration cleaner. Also note you can make your Audit_{entity} inherit from your {entity} if you wanted to.
Update
Maybe my assumption at the beginning is incorrect and you are not auditing EF entities, but any other type of audit. If that's the case, what you are looking for is a Data Provider that stores the audit events into your SQLite database.
At the time being, there is no built-in data provider that stores to SQLite, and if there was one, it would store just the JSON representation of the event in one column (like the SQL/MySql providers). But it looks like you want to have a custom schema, so you will need to implement your own data provider.
Check the documentation here.
Here is a sample skeleton of a data provider:
public class SQLiteDataProvider : AuditDataProvider
{
public override object InsertEvent(AuditEvent auditEvent)
{
// Insert the event into SQLite and return its ID
}
public override void ReplaceEvent(object eventId, AuditEvent auditEvent)
{
// Replace the event given its ID (only used for CreationPolicies InsertOnStartReplaceOnEnd and Manual)
}
// async implementation:
public override async Task<object> InsertEventAsync(AuditEvent auditEvent)
{
// Asynchronously insert the event into SQLite and return its ID
}
public override async Task ReplaceEventAsync(object eventId, AuditEvent auditEvent)
{
// Asynchronously replace the event given its ID
}
}
Then you just set it up with:
Audit.Core.Configuration.Setup()
.UseCustomProvider(new SQLiteDataProvider());
I am using EF6 but I don't know if there is any difference between that and earlier versions.
I have the following context:
public IdentityContext()
: base("name=Identity")
{
Database.SetInitializer<IdentityContext>(null);
Configuration.ProxyCreationEnabled = false;
Configuration.LazyLoadingEnabled = false;
Configuration.ValidateOnSaveEnabled = false;
Configuration.AutoDetectChangesEnabled = true;
Database.Log = logInfo => Debug.WriteLine(logInfo);
}
public DbSet<AspNetRole> AspNetRoles { get; set; }
public DbSet<AspNetUserClaim> AspNetUserClaims { get; set; }
public DbSet<AspNetUserLogin> AspNetUserLogins { get; set; }
public DbSet<AspNetUser> AspNetUsers { get; set; }
What I would like to do is to issue a SQL query against this:
I saw one example (not related to my context) which is:
using (var context = new BloggingContext())
{
var blogs = context.Blogs.SqlQuery("SELECT * FROM dbo.Blogs").ToList();
}
But this does not make any sense to me as I cannot see why there is .Blogs after the context.
For my context above can someone explain how I can issue a simple sql statement to get the Id from the AspNetUser table and place these in a collection.
Note that I am using EF6 but in this case I am not sure that is relevant to the question if I query the context. My real needs are for a complex SQL but first I need some suggestion to get me started. Thanks.
If you're using .SqlQuery, you're kind of bypassing the beauty of using LINQ-style lambda expressions to query your database.
You might need to fiddle with the syntax a bit, but something like this should work for your initial requirement of getting user IDs:
var allMyIds = context.AspNetUserLogins.Select(l => l.Id).ToList();
or, if you prefer...
var allMyIds = (from l in context.AspNetUserLogins
select l.Id).ToList();
However, if you really need to execute SQL directly, you can do it on one of the DBSet classes as in your question (in which case the EF makes a valiant attempt at change tracking), or if it's a general query you just want to execute that returns primitive types and isn't specific to any one table, do it against the Database class using ExecuteSqlCommand:
var allMyIds = context.Database.ExecuteSqlCommand("select id from AspNetUserLogins");
Hope that helps!
I have an EF object called SportDivision. For simplicity's sake, I won't include every field, just the ones that are relevant:
[Table("SportDivision", Schema = "dbo")]
public class SportDivision: BaseReferenceEntity
{
public int Id { get; set; }
public string Name { get; set; }
public int SportId { get; set; }
[ForeignKey("SportId")]
public virtual Sport Sport { get; set; }
}
So it has a SportId and it's a foreign key that points to the table Sport.
Now, I can't just use an EF object in my views, so I have a model class that's mapped to SportDivision called SportDivisionModel:
public class SportDivisionModel: BaseReferenceModel
{
public int Id { get; set; }
public string Name { get; set; }
public int SportId { get; set; }
//Read only fields
public string Sport { get; set; }
}
I use automapper to transfer data from SportDivision to SportDivisionModel and vice versa. The mapping looks like this:
Mapper.CreateMap<SportDivision, SportDivisionModel>()
.ForMember(x => x.Sport, c => c.MapFrom(e => e.Sport.Name));
Mapper.CreateMap<SportDivisionModel, SportDivision>();
And I have a genericized service that CRUDs and translates data from entity to model or model to entity. Everything works fine except on Create, of which the function is shown below:
public TModel Create<TModel, TEntity>(TModel entry)
where TModel : BaseReferenceModel
where TEntity : BaseReferenceEntity
{
var dm = ServiceLocator.Current.GetInstance<ICrudService<TEntity>>();
var raw = Mapper.Map<TModel, TEntity>(entry);
var created = dm.CreateOrUpdate(raw);
return Mapper.Map<TEntity, TModel>(dm.FindById(created.Id));
}
In the very last line, where you see dm.FindById(created.Id), it returns a SportDivisionModel object with no Sport name. A null reference exception is found in .ForMember(x => x.Sport, c => c.MapFrom(e => e.Sport.Name));. It didn't load Sport after the entry was just created in the database.
I've debugged the code, and I see that the entry with a valid SportId is entered into the SportDivision table of my database, but when I try and bring it over to my MVC application, it doesn't get all the information.
This only is an issue on create. If I simply get data from the database without creating it beforehand, or if I edit the information, then the Sport field in my model object does get populated. I don't know why this is happening, and I can't use the .Include in my generic service call (because not all BaseReferenceEntity classes have a foreign key pointing to Sport).
Please advise. Thanks in advance.
I must play Sherlock Holmes and try to derive what could be the content of CreateOrUpdate and FindById from the indications in your question:
You say that you don't use Include because of the generic service. I assume that you also don't use explicit loading (Load) because you would face the same problem that you cannot really make it generic.
Conclusion: Because the Sport navigation property in the SportDivision gets loaded in certain scenarios (Edit) this can only happen due to lazy loading. The conclusion is backed by the fact that the Sport property is marked as virtual.
Lazy loading relies on proxies. If your SportDivision entity is a proxy then
either loading the Sport entity works
or you get an exception telling you that the context is already disposed (if you have disposed the context)
Number 2 is not the case -> Conclusion: Number 1 must be the case if the pre-condition is fulfilled
But Number 1 also isn't the case (loading Sport does not work)
Conclusion: The pre-condition that your SportDivision entity is a proxy is not true.
So: SportDivision is not a proxy. Could this mean that you have lazy loading in the context disabled? No: Because you are saying that editing works it means that when you load entities from the database they are loaded as proxies and support lazy loading.
Editing works, lazy loading isn't disabled but creating a new entity does not work in the way that the Sport entity is loaded when you proceed to use the newly created entity.
Conclusion: Your newly created entity (returned from CreateOrUpdate) is not a proxy and CreateOrUpdate looks similar to this:
public TEntity CreateOrUpdate(TEntity raw) where TEntity : class
{
if (blabla)
; //update
else
{
context.Set<TEntity>().Add(raw);
context.SaveChanges();
return raw;
}
}
and FindById is just:
public TEntity FindById(int id)
{
return context.Set<TEntity>().Find(id);
}
Since you are passing raw directly into the Add method of the DbSet<T> the question raises where does raw come from and how is it created.
Obviously AutoMapper creates the entity after this line: var raw = Mapper.Map<TModel, TEntity>(entry);
How does Automapper create an entity? Probably by calling new TEntity or by using some reflection code like Activator.CreateInstance or...
It doesn't really matter how, but for sure AutoMapper doesn't instantiate an Entity Framework proxy which had to be created by:
var entity = context.Set<TEntity>().Create();
If all this is true, I feel totally screwed by AutoMapper and generic excesses. If all this wouldn't be generic we could solve the problem by:
context.Set<SportDivision>().Add(raw);
context.SaveChanges();
context.Entry(raw).Reference(r => r.Sport).Load();
Instead we must try some ugly tricks now:
context.Set<TEntity>().Add(raw);
context.SaveChanges();
context.Entry(raw).State = EntityState.Detached;
// We hope that raw is now really out of the context
raw = context.Set<TEntity>().Find(raw.Id);
// raw must be materialized as a new object -> Hurray! We have a proxy!
return raw;
(I'm really not sure if the Detached trick above does work. Aside from that you are forced to reload an entity from the database you just have created and saved which is stupid somehow.)
Potential trick number 2 (without reloading from DB but for the price of being a further step more ugly):
context.Set<TEntity>().Add(raw);
context.SaveChanges();
context.Entry(raw).State = EntityState.Detached;
// We hope that raw is now really out of the context
var anotherRaw = context.Set<TEntity>().Create(); // Proxy!
anotherRaw.Id = raw.Id;
context.Set<TEntity>().Attach(anotherRaw);
context.Entry(anotherRaw).CurrentValues.SetValues(raw);
context.Entry(anotherRaw).State = EntityState.Unchanged;
return anotherRaw; // Proxy! Lazy loading will work!
Does AutoMapper have a feature of a "custom allocator or instantiator" and can custom user data (a context) be supplied? Then there would be a chance to let AutoMapper call context.Set<TEntity>().Create();. Or is it possible to instantiate the object by hand, pass it to AutoMapper and AutoMapper just updates the object's properties?
BTW: The line...
context.Entry(anotherRaw).CurrentValues.SetValues(raw);
...is kind of EF's built-in "AutoMapper". The parameter of SetValues is a general System.Object (could be your ...Model object) and the method maps property values from the supplied object to properties of attached entities by identical property names. Maybe you can leverage this feature somehow instead of using the mapping from model to entity done by AutoMapper.
Please give me some ideas about inserting XML data in a database
The info I need to insert is from Facebook. Like User relationship info, workinfo and educatio info.
I know how to use json and deserialize the info from Facebook
Just inserting the deserilaized data into Db in XMl format is what I am not sure
Thanks for all your help
If you are using a MS SQL database there is a XML data type that you can use.
I would create models first which will represent my data which will come from XML file. For Examples;
public class Person {
public string Name { get; set; }
public string Surname { get; set; }
public bool IsInRelationship { get; set; }
//this can go on
}
As you know how to deserialize your XML, assign the values to you model.
After that you have some options here;
use an ORM system, something like Entity Framework to handle your insert operations
Create Stored Procedures and work on them
Insert you data directly by hardcoding you t-sql code.
Say you had a config object
public class MyConfig{
public int PageSize{get;set;}
public string Title{get;set;}
}
and you want to automatically generate a asp.net form to edit the properties on this object.
Do you know of any frameworks to do this automagically?
I know of MS Dynamic data, but seems I need to have the whole stack (database, linq, objects) to get this up and running. So I was thinking of something simpler..
Sorry for jumping in late. There are several ways to use Dynamic Data with POCO.
Use the DynamicObjectDataSource which is found in Futures and Preview releases of Dynamic Data, starting with July 2008 Futures. When looking in a Preview release, it contains a Futures assembly, Microsoft.Web.DynamicData.dll.
When using ASP.NET 4.0 (now in Beta), you can call a new extension method, EnableDynamicData(). See the "SimpleDynamicDataSamples" project that comes with DD Preview 4 and later.
Here's an example from that code that uses an ObjectDataSource and the POCO class called "Product".
[MetadataType(typeof(Product.Metadata))]
public partial class Product {
public class Metadata {
[Required]
public string ProductName { get; set; }
[Range(0, 100)]
public decimal UnitPrice { get; set; }
}
}
public partial class ObjectDataSourceSample : System.Web.UI.Page {
protected void Page_Init() {
// Extension method syntax
ProductsList.EnableDynamicData(typeof(Product));
// Explicit syntax
// MetaTable table = MetaTable.CreateTable(typeof(Product));
// MetaTable.MapControl(ProductsList, table);
// ProductsList.ColumnsGenerator = new DefaultAutoFieldGenerator(table);
}
}
I was under the impression that you could modify the T4 templates used by dynamic data (Not sure if you can remove the data access part).
Have you looked at just using T4 on its own.