Bulk Insert into SQL from C# App

The other option would be to use .Net framework’s SqlBulkCopy class.

The basic template would be something like

private void WriteToDatabase()

{

    // get your connection string

    string connString = ““;

    // connect to SQL

    using (SqlConnection connection =

            new SqlConnection(connString))

    {

        // make sure to enable triggers

        // more on triggers in next post

        SqlBulkCopy bulkCopy =

            new SqlBulkCopy

            (

            connection,

            SqlBulkCopyOptions.TableLock |

            SqlBulkCopyOptions.FireTriggers |

            SqlBulkCopyOptions.UseInternalTransaction,

            null

            );



        // set the destination table name

        bulkCopy.DestinationTableName = this.tableName;

        connection.Open();

        // write the data in the “dataTable”

        bulkCopy.WriteToServer(dataTable);

        connection.Close();

    }

    // reset

    this.dataTable.Clear();

    this.recordCount = 0;

}

The above code snippet shows you the API usage. But before you actually do that, you need to follow a couple of steps to setup your data table.

First, let’s look at a simple record structure (as reflected in C# class):

using System;

using System.Data;

using System.Configuration;



/// <summary>

/// Summary description for MyRecord

/// </summary>

public class MyRecord

{

    public int TestInt;

    public string TestString;

 public MyRecord()

 {

 }

    public MyRecord(int myInt, string myString)

    {

        this.TestInt = myInt;

        this.TestString = myString;

    }

}

Now, let’s start dissecting the class that we will use to upload the data:

using System;

using System.Data;

using System.Collections.Generic;



using System.Data.SqlClient;

using System.Configuration;

using System.IO;

namespace SqlExamples.FileLoader

{

/// <summary>

/// Summary description for BulkUploadToSql

/// </summary>

public class BulkUploadToSql

{

    private List<MyRecord> internalStore;

    protected string tableName;

    protected DataTable dataTable = new DataTable();

    protected int recordCount;

    protected int commitBatchSize;

Note that we have an internal List data structure as well as the DataTable. This is redundant and you can avoid using the internalStore if your application does not need to massage the data before it’s sent to SQL.

I then define 2 private constructors. The reason is that we want to use the factory pattern to return our object to the caller.

    private BulkUploadToSql(

        string tableName,

        int commitBatchSize)

    {

        internalStore = new List<MyRecord>();



        this.tableName = tableName;

        this.dataTable = new DataTable(tableName);

        this.recordCount = 0;

        this.commitBatchSize = commitBatchSize;

        // add columns to this data table

        InitializeStructures();

    }

    private BulkUploadToSql() :

        this(“MyTableName“, 1000) {}

Note that we set the commit batch size. This is a very important factor that needs to be fine tuned for your database. What this defines is the number of records that we would send in one shot to the database.

The next step is to Initialize the data table with columns that reflect the actual table structure.

private void InitializeStructures()

{

    this.dataTable.Columns.Add(“TI“, typeof(Int32));

    this.dataTable.Columns.Add(“TS“, typeof(string));

}

I then provided a factory method to load data into my internal structure from a data source. In the example code below, I use a Stream, but this can be any data source from where you wish to populate your data.

public static BulkUploadToSql Load(Stream dataSource)

{

    // create a new object to return

    BulkUploadToSql o = new BulkUploadToSql();



    // replace the code below

    // with your custom logic 

    for (int cnt = 0; cnt < 10000; cnt++)

    {

        MyRecord rec =

            new MyRecord

            (

            cnt,

            string.Format(“string{0}“, cnt)

            );

        o.internalStore.Add(rec);

    }

    return o;

}

This would make sure that our class is properly initialized and loaded with data. Once the caller has a valid object, they can now “Flush” the data as shown below:

public void Flush()

{

    // transfer data to the datatable

    foreach (MyRecord rec in this.internalStore)

    {

        this.PopulateDataTable(rec);

        if (this.recordCount >= this.commitBatchSize)

            this.WriteToDatabase();

    }

    // write remaining records to the DB

    if (this.recordCount > 0)

        this.WriteToDatabase();

}



private void PopulateDataTable(MyRecord record)

{

    DataRow row;

    // populate the values

    // using your custom logic

    row = this.dataTable.NewRow();

    row[0] = record.TestInt;

    row[1] = record.TestString;

    // add it to the base for final addition to the DB

    this.dataTable.Rows.Add(row);

    this.recordCount++;

}

In the example above, the call to Flush() actually massages the data (and at the same time loads it into the actual data table). As I mentioned before, you can actually skip this step if your application does not require massaging.

As a example of an app that uses this class:

using System;

using System.Collections.Generic;

using System.Text;

using SqlExamples.FileLoader;

using System.IO;



namespace DemoApp

{

class Program

{

    static void Main(string[] args)

    {

        using (Stream s =

            new StreamReader(@”C:\TestData.txt“))

        {

            BulkUploadToSql myData =

                BulkUploadToSql.Load(s);

            myData.Flush();

        }

    }

}

}