// Bulk Operations

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

​

// @nuget: Z.BulkOperations

​

using System;

using System.Data;

using Z.BulkOperations;

using System.Data.SqlClient;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        GenerateDatabase();

        var dtCustomers = GenerateCustomers(5);

        var dtOrders = GenerateOrders(3, dtCustomers);

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

        {

            connection.Open();

            // SAVE customers

            using (var bulk = new BulkOperation(connection))

            {

                bulk.DestinationTableName = "Customers";

                bulk.AutoMapOutputIdentity = true;

                bulk.BulkInsert(dtCustomers);

            }

            foreach(DataRow dr in dtOrders.Rows)

            {

                dr["CustomerID"] = ((DataRow)dr["CustomerRef"])["CustomerID"];

            }

            // SAVE orders

            using (var bulk = new BulkOperation(connection))

            {

                bulk.BulkInsert(dtOrders);

            }

            FiddleHelper.WriteTable(dtCustomers);

            FiddleHelper.WriteTable(dtOrders);

        }

    }

    public static DataTable GenerateCustomers(int count) 

    {

        DataTable dtTable = new DataTable("Customers");

        dtTable.Columns.Add("CustomerID", typeof(int));

        dtTable.Columns.Add("Name", typeof(string)); 

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

        {

            var drCustomer = dtTable.NewRow();  

            drCustomer["Name"] = "Customer_" + i;  

            dtTable.Rows.Add(drCustomer);

        }   

        return dtTable;

    }

    public static DataTable GenerateOrders(int count, DataTable customers) 

    {

        DataTable dtTable = new DataTable("Orders");

        dtTable.Columns.Add("OrderID", typeof(int));

        dtTable.Columns.Add("CustomerID", typeof(int));

        dtTable.Columns.Add("OrderUpdateNotes", typeof(string));

        dtTable.Columns.Add("CustomerRef", typeof(object)); 

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

        {

            var drOrder = dtTable.NewRow();  

            drOrder["OrderUpdateNotes"] = "Order_" + i;

            drOrder["CustomerRef"] = customers.Rows[i % customers.Rows.Count];

            dtTable.Rows.Add(drOrder);

        }   

        return dtTable;

    }

    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

    )

)";

                // Order table with customer ID

                command.CommandText += @"   

CREATE TABLE [Orders]

(

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

      [CustomerID] [Int] Not NULL, 

      [OrderUpdateNotes] [NVARCHAR](MAX) NULL,

    CONSTRAINT [PK_Orders] PRIMARY KEY CLUSTERED 

    (

        [OrderID] ASC

    )

)";

                command.ExecuteNonQuery();

            }

        }

    }

}