C-Sharp Script to Derive HashValue for Multiple Columns

The below script help us to create hashvalue which can be used to compare records while inserting/updating rows in a table using SSIS packages.

In script task select the columns you want to consider for deriving hashvalue and copy-paste the below code:


/* Microsoft SQL Server Integration Services Script Component
*  Write scripts using Microsoft Visual C# 2008.
*  ScriptMain is the entry point class of the script.*/

using System;
using System.Data;
using Microsoft.SqlServer.Dts.Pipeline.Wrapper;
using Microsoft.SqlServer.Dts.Runtime.Wrapper;
using Microsoft.SqlServer.Dts.Pipeline;
using System.Text;
using System.Security.Cryptography;

[Microsoft.SqlServer.Dts.Pipeline.SSISScriptComponentEntryPointAttribute]
public class ScriptMain : UserComponent

{

private PipelineBuffer inputBuffer;

public override void ProcessInput(int InputID, PipelineBuffer Buffer)

{

inputBuffer = Buffer;

base.ProcessInput(InputID, Buffer);

}



public override void Input0_ProcessInputRow(Input0Buffer Row)

{

var counter = 0;

var values = new StringBuilder();



//loop through input columns

for (counter = 0; counter < inputBuffer.ColumnCount; counter++)

{

object value;

value = inputBuffer[counter];

//add each column value to one big string

values.Append(value);

}

//set output column as results of hash method

Row.HashColumn = CreateHash(values.ToString());



base.Input0_ProcessInputRow(Row);

}



private string CreateHash(string data)

{

//get byte array of long data string

var dataToHash = (new UnicodeEncoding()).GetBytes(data);

//create hash provider and compute hash of byte array

var sha1 = new SHA1CryptoServiceProvider();

var hashedData = sha1.ComputeHash(dataToHash);

RNGCryptoServiceProvider.Create().GetBytes(dataToHash);

//convert results to hexadecimal string (SQL friendly format)

var result = BitConverter.ToString(hashedData).Replace("-", "");

return result;

}

}