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Entity Framework Bulk Insert Throws KeyNotFoundException error

由 心不动则不痛 提交于 2019-12-01 15:36:09

With modifications to the code in this blog post, here's what worked for my Code First Fluent API setup after encountering the same "The given key was not present in the dictionary" error on BulkInsert(). The only dependency here is the ToDataTable() extension method found in the DataExtensions snippet of the aforementioned post.

The relevant part is the GetColumnMappings() method which gets the POCO class property's preferred name (the one you specified in code) as the source column name (in the enumerable-turned-datatable) and pairs it with the metadata member's name (the DB column name) as the destination column name.

GetColumnMappings():

private IEnumerable<SqlBulkCopyColumnMapping> GetColumnMappings<T>()
{
    var storageMetadata = ((EntityConnection)objectContext.Connection).GetMetadataWorkspace().GetItems(DataSpace.SSpace);
    var entityPropMembers = storageMetadata
        .Where(s => (s.BuiltInTypeKind == BuiltInTypeKind.EntityType))
        .Select(s => (EntityType)s)
        .Where(p => p.Name == typeof(T).Name)
        .Select(p => (IEnumerable<EdmMember>)(p.MetadataProperties["Members"].Value))
        .First();

    var sourceColumns = entityPropMembers.Select(m => (string)m.MetadataProperties["PreferredName"].Value);
    var destinationColumns = entityPropMembers.Select(m => m.Name);

    return Enumerable.Zip(sourceColumns, destinationColumns, (s, d) => new SqlBulkCopyColumnMapping(s, d));
}

Full Code:

// Modified from: https://ruijarimba.wordpress.com/2012/03/25/bulk-insert-dot-net-applications-part1 and
// https://ruijarimba.wordpress.com/2012/03/18/entity-framework-get-mapped-table-name-from-an-entity/

internal class BulkInserter
{
    private readonly ObjectContext objectContext;

    private readonly IDbConnection connection;

    internal BulkInserter(DbContext contextAdapter)
    {
        objectContext = ((IObjectContextAdapter)contextAdapter).ObjectContext;
        connection = contextAdapter.Database.Connection;
    }

    public void Insert<T>(IEnumerable<T> items) where T : class
    {
        EnsureOpenConnection();
        using (var bulkCopy = new SqlBulkCopy((SqlConnection)connection)
        {
            DestinationTableName = GetTableName<T>(),
        })
        {
            foreach (var mapping in GetColumnMappings<T>())
            {
                bulkCopy.ColumnMappings.Add(mapping);
            }

            bulkCopy.WriteToServer(items.ToDataTable());
        }
    }
    private void EnsureOpenConnection()
    {
        if (connection.State == ConnectionState.Closed)
        {
            connection.Open();
        }
    }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1004:GenericMethodsShouldProvideTypeParameter")]
    private string GetTableName<T>() where T : class
    {
        string sql = objectContext.CreateObjectSet<T>().ToTraceString();
        Regex regex = new Regex("FROM (?<table>.*) AS");
        Match match = regex.Match(sql);

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

    private IEnumerable<SqlBulkCopyColumnMapping> GetColumnMappings<T>()
    {
        var storageMetadata = ((EntityConnection)objectContext.Connection).GetMetadataWorkspace().GetItems(DataSpace.SSpace);
        var entityPropMembers = storageMetadata
            .Where(s => (s.BuiltInTypeKind == BuiltInTypeKind.EntityType))
            .Select(s => (EntityType)s)
            .Where(p => p.Name == typeof(T).Name)
            .Select(p => (IEnumerable<EdmMember>)(p.MetadataProperties["Members"].Value))
            .First();

        var sourceColumns = entityPropMembers.Select(m => (string)m.MetadataProperties["PreferredName"].Value);
        var destinationColumns = entityPropMembers.Select(m => m.Name);

        return Enumerable.Zip(sourceColumns, destinationColumns, (s, d) => new SqlBulkCopyColumnMapping(s, d));
    }
}

Ok, I had a same error couldnt find any answers online so had to look deep so here is what i figured:

When your entity has an inherited and the child entities if not defined as part of the DBSet it flags an error such kind, secondly, not sure why it expects the new DbContext with just the related entity used for bulkInsertions if there is any other entities out there it raises the same error.

So its the 2 cause so i had to fix these both, and running like an horse!!!

its worth trying, so give a try

The "BulkInsert" library is very fast but not very flexible and unsupported.

It doesn't support all type of inheritance (TPC, TPT) and has some issue with column mapping.

The issue you got is for one of these reasons.

Disclaimer: I'm the owner of the project Entity Framework Extensions

This library is the ultimate library for performance and allow to:

  • BulkSaveChanges
  • BulkInsert
  • BulkUpdate
  • BulkDelete
  • BulkMerge

All inheritance and association are supported.

Example:

using (var db = new Entities(myConnectionString)
{
    db.BulkInsert(contactsToInsert);
}

// BulkSaveChanges is slower than BulkInsert but way faster then SaveChanges
using (var db = new Entities(myConnectionString))
{
    db.Contacts.AddRange(contactsToInsert);
    db.BulkSaveChanges();
}
标签
c#
entity-framework
bulkinsert
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