// Bulk Operations

// Doc: https://bulk-operations.net/bulk-delete

​

// @nuget: Z.BulkOperations

​

using System.Collections.Generic;

using System.Data;

using System.Data.SqlClient;

using System.Linq;

using Z.BulkOperations;

public class Program

{

    public static void Main()

    {

        int count = 5;

        GenerateDatabase();

        SeedCustomers(count);       

        var customers = GenerateCustomers(count);

        using (var connection = new SqlConnection(FiddleHelper.GetConnectionStringSqlServer()))

        {

            connection.Open();

            // SHOW data

            ShowData(connection, "1 - Customers Before");

            // Delete customers

            using (var bulk = new BulkOperation<Customer>(connection))

            {

                bulk.DestinationTableName = "Customers";

​

                var toDelete = customers.Take(customers.Count() / 2);

                bulk.BatchSize = 100;

                bulk.BulkDelete(toDelete);

            }

            // SHOW data

            ShowData(connection, "3 - Customers After");

        }

    }

    public static void ShowData(SqlConnection connection, string text)

    {

        // SHOW data

        using (var command = connection.CreateCommand())

        {

            command.CommandText = @"

SELECT * FROM Customers

";

            var ds = new DataSet();

            var sqlDataAdapter = new SqlDataAdapter(command);

            sqlDataAdapter.Fill(ds);

​

            ds.Tables[0].TableName = text;

​

            FiddleHelper.WriteTable(ds.Tables[0]);

        }

    }

    public static List<Customer> GenerateCustomers(int count, bool useOld = false) 

    {

        List<Customer>  list = new List<Customer>();

        for(int i = 0; i < count; i++)

        {

            list.Add(new Customer() { CustomerID = (i + 1), Name =  "Customer_" + i});

        }

        return list;

    }

    public static void SeedCustomers(int count) 

    {

        var customers = GenerateCustomers(count, true);

        using (var connection = new SqlConnection(FiddleHelper.GetConnectionStringSqlServer()))

        {

            connection.Open();

            // SAVE customers

            using (var bulk = new BulkOperation<Customer>(connection))

            {

                // easy to use

                bulk.DestinationTableName = "Customers";

​

                bulk.BulkInsert(customers);

            }

        }

    }

    public static void GenerateDatabase()

    {

        using (var connection = new SqlConnection(FiddleHelper.GetConnectionStringSqlServer()))

        {

            connection.Open();

            using (var command = connection.CreateCommand())

            {

                command.CommandText = @"   

CREATE TABLE [Customers]

(

    [CustomerID] [INT] IDENTITY(1,1) NOT NULL,

    [Name] [NVARCHAR](MAX) NULL,

    CONSTRAINT [PK_Customers] PRIMARY KEY CLUSTERED 

    (

        [CustomerID] ASC

    )

)";

                command.ExecuteNonQuery();

            }

        }

    }

    public class Customer

    {

        public int CustomerID { get; set; }

        public string Name { get; set; }

    }

}