MVC 5 - Logging inserts and updates in database - asp.net-mvc

Question

I have looked for alot of different approaches to achive this. But I have yet to find a good and simple exmaple on how to do this without alot of 3 party instalations wich focuses on performance logging and debugging.
I am looking for a way to easily log ALL changes to my database and also when new rows are added. I want to have a own table that stores which action in which controller was called / or simply the database table would be enough to track it. And the which fields where updated or added.
I am picturing a table something like this:
ID - ACTION/TABLE/METHOD - ID - TYPE - DETAILS - CREATED BY - TIMESTAMP
x - TableName/ActionResult/JsonResult/ - ID of the new or updated item - updated or new - details on what have changed or created - user.identity - timestamp
So i can view the log table in each spesific view and i can see the history for that item and which fields where changed etc.
I looked at the bottom suggestion here: How to implement a MVC 4 change log? since my SQL database does not support the SQL Service Broker and I dont really want to start with adding Triggers in SQL.
I am using MVC 5.2 and EF 6.0 so I have looked at the Database.Log property but I really need some guidance on how to set up a good method to achive what I want.

Answer 1

I found a solution i am currently modifying to my needs.
Here is the code:
Overriding SaveChanges Class in
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
and adding theese methods:
public async Task SaveChangesAsync(string userId)
{
// Get all Added/Deleted/Modified entities (not Unmodified or Detached)
foreach (var ent in this.ChangeTracker.Entries().Where(p => p.State == EntityState.Added || p.State == EntityState.Deleted || p.State == EntityState.Modified))
{
// For each changed record, get the audit record entries and add them
foreach (Log x in GetAuditRecordsForChange(ent, userId))
{
this.Log.Add(x);
}
}
// Call the original SaveChanges(), which will save both the changes made and the audit records
await base.SaveChangesAsync();
}
private List<Log> GetAuditRecordsForChange(DbEntityEntry dbEntry, string userId)
{
List<Log> result = new List<Log>();
DateTime changeTime = DateTime.Now;
// Get the Table() attribute, if one exists
TableAttribute tableAttr = dbEntry.Entity.GetType().GetCustomAttributes(typeof(TableAttribute), false).SingleOrDefault() as TableAttribute;
// Get table name (if it has a Table attribute, use that, otherwise get the pluralized name)
string tableName = tableAttr != null ? tableAttr.Name : dbEntry.Entity.GetType().Name;
// Get primary key value (If you have more than one key column, this will need to be adjusted)
string keyName = dbEntry.Entity.GetType().GetProperties().Single(p => p.GetCustomAttributes(typeof(KeyAttribute), false).Count() > 0).Name;
if (dbEntry.State == EntityState.Added)
{
// For Inserts, just add the whole record
// If the entity implements IDescribableEntity, use the description from Describe(), otherwise use ToString()
result.Add(new Log()
{
LogID = Guid.NewGuid(),
EventType = "A", // Added
TableName = tableName,
RecordID = dbEntry.CurrentValues.GetValue<object>(keyName).ToString(), // Again, adjust this if you have a multi-column key
ColumnName = "*ALL", // Or make it nullable, whatever you want
NewValue = (dbEntry.CurrentValues.ToObject() is IDescribableEntity) ? (dbEntry.CurrentValues.ToObject() as IDescribableEntity).Describe() : dbEntry.CurrentValues.ToObject().ToString(),
Created_by = userId,
Created_date = changeTime
}
);
}
else if (dbEntry.State == EntityState.Deleted)
{
// Same with deletes, do the whole record, and use either the description from Describe() or ToString()
result.Add(new Log()
{
LogID = Guid.NewGuid(),
EventType = "D", // Deleted
TableName = tableName,
RecordID = dbEntry.OriginalValues.GetValue<object>(keyName).ToString(),
ColumnName = "*ALL",
NewValue = (dbEntry.OriginalValues.ToObject() is IDescribableEntity) ? (dbEntry.OriginalValues.ToObject() as IDescribableEntity).Describe() : dbEntry.OriginalValues.ToObject().ToString(),
Created_by = userId,
Created_date = changeTime
}
);
}
else if (dbEntry.State == EntityState.Modified)
{
foreach (string propertyName in dbEntry.OriginalValues.PropertyNames)
{
// For updates, we only want to capture the columns that actually changed
if (!object.Equals(dbEntry.OriginalValues.GetValue<object>(propertyName), dbEntry.CurrentValues.GetValue<object>(propertyName)))
{
result.Add(new Log()
{
LogID = Guid.NewGuid(),
EventType = "M", // Modified
TableName = tableName,
RecordID = dbEntry.OriginalValues.GetValue<object>(keyName).ToString(),
ColumnName = propertyName,
OriginalValue = dbEntry.OriginalValues.GetValue<object>(propertyName) == null ? null : dbEntry.OriginalValues.GetValue<object>(propertyName).ToString(),
NewValue = dbEntry.CurrentValues.GetValue<object>(propertyName) == null ? null : dbEntry.CurrentValues.GetValue<object>(propertyName).ToString(),
Created_by = userId,
Created_date = changeTime
}
);
}
}
}
// Otherwise, don't do anything, we don't care about Unchanged or Detached entities
return result;
}
public DbSet<Log> Log { get; set; }
And here is the Log class
[Table("N_Log")]
public class Log
{
[Key]
public Guid LogID { get; set; }
[Required]
public string EventType { get; set; }
[Required]
public string TableName { get; set; }
public string ActionID { get; set; }
[Required]
public string RecordID { get; set; }
[Required]
public string ColumnName { get; set; }
public string OriginalValue { get; set; }
public string NewValue { get; set; }
[Required]
public string Created_by { get; set; }
[Required]
public DateTime Created_date { get; set; }
}