I have a model with several entities in my MVC4 project with VS 2012. Recently I added a view to my DB named 'vwTeacherNames' and I tried to update the model and I unchecked the Plorizing option for that update.
Then, I rename my entity to 'TeacherName'. Now when I tun the Prj, this exception is thrown where I define a DropDownList for teachers:
Invalid object name 'dbo.TeacherNames'.
I tried many ways such as using custom tool, removing the .tt files and generating the again, ... However the problem stays firm!
So, how can I tell the EF the right table(in fact view) name which is vwTeacherNames?
Thanks a lot
Found it! and I add it here with some more tweaks:
public class myDbContext : DbContext
{
public PtDbContext()
: base("DefaultConnection")
{
}
... //some entities
//Here it is:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<TeacherName>().Property(t => t.FullName)
.HasColumnName("TeacherName");
modelBuilder.Entity<TeacherName>().ToTable("vwTeacherNames", schemaName: "dbo");
}
}
Update: Why waisting your time by defining what you previously defined?! Just kill the default table naming convention and enjoy progressing your Prj:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//Adding this line tells the EF not to go through that convention
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
}
So, It should builds up your queries by EntitySetName and EntityName properties of your entities which the first of is the DB table name and the second is your entity name which you use in your DbContext.
Related
I suppose this question is a cosmetic one; when you initially create an EF migration, it puts the schema in by default; for example:
public override void Up()
{
DropPrimaryKey("dbo.MyTable");
AddPrimaryKey("dbo.MyTable", "NewField");
This seems fine, unit you see the key name that it generates as a result (it has dbo in the key name).
I realise that one way around this is to specify the key name directly. Are there any other options, for example, can the schema be specified for a block, but not included in the specific modifications? For example:
public override void Up()
{
UseSchema("dbo");
DropPrimaryKey("MyTable");
AddPrimaryKey("MyTable", "NewField");
I realise that you can simply omit the schema name; i.e., this will work:
public override void Up()
{
DropPrimaryKey("MyTable");
AddPrimaryKey("MyTable", "NewField");
But how would I then deal with a situation where there were more than a single schema?
You can specify default schema using HasDefaultSchema method on DbModelBuilder class instance.
modelBuilder.HasDefaultSchema("schemaName");
You can also set schema for each entity using ToTable method on EntityTypeConfiguration<TEntityType> class instance. Which will generate migration scripts with provided schema for desired entity/ies.
modelBuilder.Entity<TEntity>().ToTable("tableName", "schemaName")
You can also use Table attribute to set schema for entity.
[Table("tableName","schemaName")]
Or you can write your own custom convention
public class DynamicSchemaConvention : Convention
{
public CustomSchemaConvention()
{
Types().Configure(c => c.ToTable(c.ClrType.Name, c.ClrType.Namespace.Substring(c.ClrType.Namespace.LastIndexOf('.') + 1)));
}
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Add(new CustomSchemaConvention());
}
Related links:
DbModelBuilder.HasDefaultSchema Method
EntityTypeConfiguration.ToTable Method
TableAttribute Class
Entity Framework 6 - Code First: table schema from classes' namespace
Entity Framework Custom Code First Conventions (EF6 onwards)
By default the tables's schema of Identity Server 4 is dbo, i want change it to security, so i create ConfigurationContext which inherit from ConfigurationDbContext:
public class ConfigurationContext : ConfigurationDbContext
{
public ConfigurationContext(DbContextOptions<ConfigurationDbContext> options, ConfigurationStoreOptions storeOptions) : base(options, storeOptions)
{ }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.HasDefaultSchema("Security");
}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
var relationalOptions = RelationalOptionsExtension.Extract(optionsBuilder.Options);
relationalOptions.MigrationsHistoryTableSchema = "Security";
}
}
and in add-migration i use ConfigurationContext :
Add-Migration -c ConfigurationContext
but i got this error:
No parameterless constructor was found on 'ConfigurationContext'. Either add a parameterless constructor to 'ConfigurationContext' or add an implementation of 'IDbContextFactory' in the same assembly as 'ConfigurationContext'.
what is the problem?
IdentityServer4 provides this option. In ConfigureServices,
services.AddIdentityServer()
.AddOperationalStore(builder => builder.UseSqlServer(cnStr, options =>
options.MigrationsAssembly(migAssembly)),
storeOption => storeOption.DefaultSchema = "security")
This way, you can continue to use the IDbContextFactory as suggested in the quickstarts.
I know this is quite an old question, but I recently had a similar issue; June Lau's answer does provide some of the info you need to resolve this, but the important part is that migrations don't inspect the database context at runtime, so you need to define the schema before you create your database migration.
Don't worry about extending ConfigurationDbContext either, as that's not needed, just add something like this to your ConfigureServices method in Startup.cs:
var identityServerBuilder = services.AddIdentityServer(options =>
{
// ...
});
var migrationsAssembly = typeof(Startup).GetTypeInfo().Assembly.GetName().Name;
identityServerBuilder.AddConfigurationStore(options =>
{
options.DefaultSchema = "config";
options.ConfigureDbContext = b => b.UseSqlServer(connectionString, sql => sql.MigrationsAssembly(migrationsAssembly));
});
Once you've added that code, create a migration for the relevant database context:
Add-Migration CreateInitialSchema -Context ConfigurationDbContext
You should see that the created migration starts like this:
protected override void Up(MigrationBuilder migrationBuilder)
{
migrationBuilder.EnsureSchema(
name: "config");
migrationBuilder.CreateTable(
name: "ApiResources",
schema: "config",
columns: table => new ...
The problem is that Add-Migration -c ConfigurationContext command does not startup your application and thus does not know how to resolve the classes in your constructor:
public ConfigurationContext( //How do i resolve this, i dont know?
DbContextOptions<ConfigurationDbContext> options,
ConfigurationStoreOptions storeOptions)
: base(options, storeOptions)
{ }
You need to add a parameterless constructor, as the error suggests:
public ConfigurationContext()
: base(/* todo default static logic here */)
{ /* and here */ }
Why
The database migration tries to create an instance of the ConfigurationContext to determine the 'desired' state (the state you want your database to be after the database migration has been executed).
This migration is a static file inside your project saying which Columns and which indexes etc need to be added or removed to the database to create the 'desired' state.
This Add-Migration command simply reflects your code to find the right context, it does not go through your startup class to see which dependencies you have the find (this would become way to complex since there could also be runtime dependencies or dependencies based on App-settings, etc)
I'm working with an existing database. I've a table called ClientCode, i.e. the table itself is not pluralized.
If I create a class called iHROrgCode, will Entity Framework map it to the table with the same name? If not, what should I do to get the result?
Thanks for helping
Inside your DB Context -> OnModelCreating method, add the following line
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<iHROrgCode>().ToTable("ClientCode");
base.OnModelCreating(modelBuilder);
}
I have an existing database, to which I'd like to add Entity Framework mappings for just a handful of tables/entities. Is there a way to ignore all entities by default, and then selectively include them?
I have this in the context constructor to not migrate changes:
Database.SetInitializer(new NullDatabaseInitializer<Context>());
And then I have the following fluent code to map the existing entities:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Cube>()
.Map(e => e.ToTable("tblCubes"))
.HasKey(e => e.CubeId);
...
However, when I run any EF queries, I get the error:
One or more validation errors were detected during model generation.
EntityType 'xyz' has no key defined. Define the key for this EntityType
Rather than using modelBuilder.Ignore<xyz>(); on every existing and future entity, can't I just get EF to ignore all by default, and only map those I choose/include?
EDIT============
One of my EF entities (CubeFact) has relational properties to other classes like this one below to the Year class:
private Year _year;
public Int16 YearId { get; set; }
public Year Year { get { return _year ?? (_year = Year.GetYearById(YearId)); } set { _year = value; } }
The Year class then links to a Fact class, which is one of the classes failing validation. But neither the Year class nor the Fact class have been explicitly mapped. Does EF follow these relationships and then validate, even if I haven't explicitly told it about the relationships?
I'm currently using EF5 in a project with a legacy database. The legacy application uses dynamically build tables (xxxx_year, yyyy_year) to store "year based data". I've been trying to find a way to dynamically map the ef entities (xxxx, yyyy, etc) to the tables, based on the year property value, but I always end up getting the "The model backing the context has changed since the database was created." error. Can anyone give me some ideas on how to accomplish this ?
I found some old blog posts talking about edm mapping, where we can separate mapping tables based on some property value (kind of horizontal partitioning), but I can't find any pointers on how to accomplish the same using code first.
Thanks, P
In your mapping configuration for each domain object, you can tell EF that the corresponding table name for an entity is different from the entity name itself.
If your class is called YyyyYear, it can point to a table called "2012_year" by specifying the name in its mapping file.
e.g.
// 1 entity class per db table
public class YyyyYear
{
public int Id { get; set; }
}
// 1 mapping file for entity
using System.Data.Entity.ModelConfiguration;
public class YyyyYearMap: EntityTypeConfiguration
{
public YyyyYearMap()
{
this.HasKey(t => t.Id);
this.ToTable("2012_year");
}
}
// your db context class (derives from DbContext)
using System.Data.Entity;
public class MyDbContext: DbContext
{
// 1 db set for every entity/table
public DbSet YyyyYears { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
// 1 mapping file for every entity/table
modelBuilder.Configurations.Add(new YyyyYearMap());
}
}
I'm not sure if that's what you're looking for, but I have a blog post with step-by-step instructions, a working sample, and how to resolve common issues.
http://wakeupandcode.com/entity-framework-code-first-migrations/
Hope this helps!