Update table based on ID reference comparing each column and value

Hi,

Through UI user can update any information and click save. In backend i will be receiving only ID as reference . Based on the ID value i should update multiple tables wherever i have the reference tables. Here i will not get the values or column name updated. I just get a ID to find which row is updated.

I should do a comparision now. 

I have a history table where i get the row before updation. and i get a row after updation from current data i.e. from ssdb_Railroad[This will be updated by java after updation we will get the ID inorder to update remaining tables]. Now i need to compare both the table column values and know which column is updated and after getting the value i should update reference tables.

Below is the structure for comparision table , History table and Main table.

Create table Comparision_History (
 ID   int IDENTITY(1,1) PRIMARY KEY,
 InsertUser_UpdateUser varchar(50),
 Old_ColVal  varchar(100),
 New_ColVal  varchar(100),
 TableName   varchar(100),
 [Action]     varchar(50),
 InsertDate_UpdateDate Datetime NOT NULL DEFAULT getdate()
 )

CREATE TABLE SSDB_Railroad_History (
    ID         int IDENTITY PRIMARY KEY,
SCAC       varchar(4) ,
Name       varchar(50) NOT NULL,
RailroadID int NOT NULL UNIQUE,
RC2Key  varchar(50),
NOTES      varchar(1000),
[Action]   varchar(50),
InsertDate_UpdateDate  Datetime NOT NULL DEFAULT getdate(),
InsertUser_UpdateUser  varchar(50),

)

CREATE TABLE SSDB_Railroad (
    ID   int IDENTITY(1,1)PRIMARY KEY,
SCAC varchar(4) UNIQUE,
Name varchar(50) NOT NULL,
RailroadID int NOT NULL UNIQUE,
RC2Key varchar(50),
InsertDate Datetime NOT NULL DEFAULT getdate(),
UpdateDate Datetime,
InsertUser varchar(50),
UpdateUser varchar(50)

)

Here SSDB_Railroad table and History table needs to be compared and get a updated value and it should be inserted in a comparision table. as well as it should be updated in reference tables.

Please help me with the code.

Thanks in Advance

---

Deepa