DbSet table name

问题

To get database table name on Entity framework 4.0 I do:

ObjectSetInstance.EntitySet.ToString()

Is there a way to do this on Entity Framework 4.1?

回答1:

Try something like this:

string name = (context as IObjectContextAdapter).ObjectContext.CreateObjectSet<MyClass>().EntitySet.Name;

回答2:

Extension methods for DbContext and ObjectContext:

public static class ContextExtensions
{
    public static string GetTableName<T>(this DbContext context) where T : class
    {
        ObjectContext objectContext = ((IObjectContextAdapter) context).ObjectContext;

        return objectContext.GetTableName<T>();
    }

    public static string GetTableName<T>(this ObjectContext context) where T : class
    {
        string sql = context.CreateObjectSet<T>().ToTraceString();
        Regex regex = new Regex("FROM (?<table>.*) AS");
        Match match = regex.Match(sql);

        string table = match.Groups["table"].Value;
        return table;
    }
}

Using a ObjectContext object:

ObjectContext context = ....;
string table = context.GetTableName<Foo>();

Using a DbContext object:

DbContext context = ....;
string table = context.GetTableName<Foo>();

More info here:

Entity Framework: Get mapped table name from an entity

回答3:

As of EF6.1, the solution explored in this article shows how to use the newly exposed metadata to accomplish this, should not require the database to be initialized or depend on what method was used to set the table name.

回答4:

You can try something like this.

private string GetTableName(Type type)
{
  var tableAttribute = type.GetCustomAttributes(false).OfType<System.ComponentModel.DataAnnotations.TableAttribute>().FirstOrDefault();
  return tableAttribute == null ? type.Name : tableAttribute.Name;
}

You can call this string like this.

var tableName = GetTableName(entityType.FirstOrDefault());

Please see the below link for further info. Link

回答5:

I also found that CreateObjectSet() doesn't quite do the job, particularly when getting column names for use in SqlBulCopy(). The following code for getting the EntitySet seems to work better,

 private EntitySet GetEntitySet<T>(DbContext context)
{
    var type = typeof(T);
    var entityName = type.Name;
    var metadata = ((IObjectContextAdapter)context).ObjectContext.MetadataWorkspace;

    IEnumerable<EntitySet> entitySets;
    entitySets = metadata.GetItemCollection(DataSpace.SSpace)
                     .GetItems<EntityContainer>()
                     .Single()
                     .BaseEntitySets
                     .OfType<EntitySet>()
                     .Where(s => !s.MetadataProperties.Contains("Type")
                                 || s.MetadataProperties["Type"].ToString() == "Tables");
    var entitySet = entitySets.FirstOrDefault(t => t.Name == entityName);
    return entitySet;
}

To get the table name, there's two other methods I use instead of EntitySet.Name which returns the singular rather than pluralized name.

public string GetTableName<T>(DbContext context)
            where T: class
{
    var entitySet= GetEntitySet<T>(context);
    if (entitySet == null)
        throw new Exception("Unable to find entity set '{0}' in edm metadata".F(typeof(T).Name));
    var tableName = GetStringProperty(entitySet, "Schema") + "." + GetStringProperty(entitySet, "Table");
    return tableName;
}

private string GetStringProperty(MetadataItem entitySet, string propertyName)
{
    MetadataProperty property;
    if (entitySet == null)
        throw new ArgumentNullException("entitySet");
    if (entitySet.MetadataProperties.TryGetValue(propertyName, false, out property))
    {
        string str = null;
        if (((property != null) &&
            (property.Value != null)) &&
            (((str = property.Value as string) != null) &&
            !string.IsNullOrEmpty(str)))
        {
            return str;
        }
    }
    return string.Empty;
}

This returns the actual name used in the database and well as the db schema (in case you're not using dbo), and should work with data annotations or fluent configuration.

The only caveat may be that the database should already be initialized. (which I think is the problem with using CreateObjectSet() - there's a step missing which resolves the db schema).

回答6:

Source: https://msdn.microsoft.com/en-gb/data/jj819164.aspx

using System.Data.Entity;
using System.Data.Entity.Infrastructure.DependencyResolution;
using System.Data.Entity.Infrastructure.Pluralization;

var service = DbConfiguration.DependencyResolver.GetService<IPluralizationService>();
var entitySetName = service.Pluralize(typeof(TEntity).Name));

来源：https://stackoverflow.com/questions/6598857/dbset-table-name