Tanneryd.BulkOperations.EF6 1.2.0-beta1

Tanneryd.BulkOperations.EF6

A nuget package that extends the DbContext in EF6 with bulk operations for both inserts and updates.

Getting Started

Read the CodeProject article Bulk operations using Entity Framework if you are interested in some background.

Prerequisites

The extension is built for, and requires, Entity Framework 6 and .NET 4.5 or later.

Installing

Install the nuget package Tanneryd.BulkOperations.EF6. This will make the following methods available on the DbContext.

Using

Insert

public class BulkInsertRequest<T>
{
    public IList<T> Entities { get; set; }
    public SqlTransaction Transaction { get; set; }
    public bool Recursive { get; set; }
    public bool AllowNotNullSelfReferences { get; set; }
    public bool SortUsingClusteredIndex { get; set; }
}

• When Recursive is set to true the entire entity hierarchy will be inserted.
• When AllowNotNullSelfReferences is set to true, entities with self referencing foreign keys declared as NOT NULL will be properly inserted. But, this will only work if the database user has the required privileges to execute ALTER TABLE <table name> NOCHECK CONSTRAINT ALL and ALTER TABLE <table name> CHECK CONSTRAINT ALL.
• When SortUsingClusteredIndex is set to true the entities will be sorted according to the clustered index of the target table.

 public static BulkOperationResponse BulkInsertAll<T>(
     this DbContext ctx,
     BulkInsertRequest<T> request)

Update

public class BulkUpdateRequest
{
    public IList Entities { get; set; }
    public string[] UpdatedColumnNames { get; set; }
    public string[] KeyMemberNames { get; set; }
    public SqlTransaction Transaction { get; set; }
    public bool InsertIfNew { get; set; }
}

• If UpdatedColumnNames is an empty list all non-key mapped columns will be updated, otherwise only the columns specified.
• If KeyMemberNames is an empty list the primary key columns will be used to select which rows to update, otherwise the columns specified will be used.

 public static BulkOperationResponse BulkUpdateAll(
     this DbContext ctx,
     BulkUpdateRequest request)

SelectExisting

The select-existing feature provides a way to identify the subset of existing or non-existing items in a collection where an item is considered as existing if it is equal to an entity saved in the database according to a set of defined key properties. This provides a very efficient way of figuring out which items in a collection needs to be inserted and which to be updated. The item collection can be of the same type as the EF entity but it does not have to be.

public class KeyPropertyMapping
{
    public string ItemPropertyName { get; set; }
    public string EntityPropertyName { get; set; }

    public static KeyPropertyMapping[] IdentityMappings(string[] names)
    {
        return names.Select(n => new KeyPropertyMapping
        {
            ItemPropertyName = n,
            EntityPropertyName = n
        }).ToArray();
    }
}

public class BulkSelectRequest<T>
{
    public BulkSelectRequest(string[] keyPropertyNames)
    {
        KeyPropertyMappings = keyPropertyNames.Select(n => new KeyPropertyMapping
            {
                ItemPropertyName = n,
                EntityPropertyName = n
            })
            .ToArray();
    }
    public IList<T> Items { get; set; }
    public KeyPropertyMapping[] KeyPropertyMappings { get; set; }
    public SqlTransaction Transaction { get; set; }


    public BulkSelectRequest()
    {
        KeyPropertyMappings = new KeyPropertyMapping[0];
        Items = new T[0];
    }
}

/// <summary>
/// Given a set of entities we return the subset of these entities
/// that already exist in the database, according to the key selector
/// used.
/// </summary>
/// <typeparam name="T1">The item collection type</typeparam>
/// <typeparam name="T2">The EF entity type</typeparam>
/// <param name="ctx"></param>
/// <param name="request"></param>
public static IList<T1> BulkSelectExisting<T1,T2>(
    this DbContext ctx,
    BulkSelectRequest<T1> request)
{
    return DoBulkSelectExisting<T1, T2>(ctx, request);
}

Built With

• Visual Studio 2017
• .NET Framework 4.5
• Entity Framework 6.0.2

Versioning

We use SemVer for versioning. For the versions available, see the tags on this repository.

Authors

• Måns Tånneryd

License

This project is licensed under the Apache License - see the LICENSE.md file for details.