Entity Framework Plus Audit - AutoSave
Problem
You need to automatically save audit entries in the database to keep a history in an audit table.
Solution
If an action for the property AutoSavePreAction is set, audit entries will automatically be saved in the database when SaveChanges or SaveChangesAsync methods are called.
By using EF+ Audit entity
public class EntityContext : DbContext { // ... context code ... public DbSet<AuditEntry> AuditEntries { get; set; } public DbSet<AuditEntryProperty> AuditEntryProperties { get; set; } static EntityContext() { AuditManager.DefaultConfiguration.AutoSavePreAction = (context, audit) => // ADD "Where(x => x.AuditEntryID == 0)" to allow multiple SaveChanges with same Audit (context as EntityContext).AuditEntries.AddRange(audit.Entries); } } var audit = new Audit(); audit.CreatedBy = "ZZZ Projects"; // Optional ctx.SaveChanges(audit);
By using a different context
public class OracleContext : DbContext { // ... context code ... } public class SqlServerContext : DbContext { // ... context code ... public DbSet<AuditEntry> AuditEntries { get; set; } public DbSet<AuditEntryProperty> AuditEntryProperties { get; set; } } AuditManager.DefaultConfiguration.AutoSavePreAction = (context, audit) => { var sqlServerContext = new SqlServerContext(); sqlServerContext.AuditEntries.AddRange(audit.Entries); sqlServerContext.SaveChanges(); }; var audit = new Audit(); audit.CreatedBy = "ZZZ Projects"; // Optional oracleContext.SaveChanges(audit);
Custom AuditEntry & Database First Approach
AuditManager.DefaultConfiguration.AutoSavePreAction = (context, audit) =>
{
// ADD "Where(x => x.AuditEntryID == 0)" to allow multiple SaveChanges with same Audit
var customAuditEntries = audit.Entries.Select(x => Import(x));
(context as Entities).AuditEntries.AddRange(customAuditEntries);
};
using (var ctx = new Entities())
{
Audit audit = new Audit();
audit.CreatedBy = "ZZZ Projects"; // Optional
ctx.Entity_Basic.Add(new Entity_Basic() {ColumnInt = 2});
ctx.SaveChanges(audit);
}
public Static AuditEntry Import(Z.EntityFramework.Plus.AuditEntry entry)
{
var customAuditEntry = new AuditEntry
{
EntitySetName = entry.EntitySetName,
EntityTypeName = entry.EntityTypeName,
State = (int)entry.State,
StateName = entry.StateName,
CreatedBy = entry.CreatedBy,
CreatedDate = entry.CreatedDate
};
customAuditEntry.AuditEntryProperties = entry.Properties.Select(x => Import(x)).ToList();
return customAuditEntry;
}
public Static AuditEntryProperty Import(Z.EntityFramework.Plus.AuditEntryProperty property)
{
var customAuditEntry = new AuditEntryProperty
{
RelationName = property.RelationName,
PropertyName = property.PropertyName,
OldValue = property.OldValueFormatted,
NewValue = property.NewValueFormatted
};
return customAuditEntry;
}
Saving automatically by overriding SaveChanges & SaveChangesAsync
AuditManager.DefaultConfiguration.AutoSavePreAction = (context, audit) =>
// ADD "Where(x => x.AuditEntryID == 0)" to allow multiple SaveChanges with same Audit
(context as TestContext).AuditEntries.AddRange(audit.Entries);
public class EntityContext : DbContext
{
// ... context code ...
public override int SaveChanges()
{
var audit = new Audit();
audit.PreSaveChanges(this);
var rowAffecteds = base.SaveChanges();
audit.PostSaveChanges();
if (audit.Configuration.AutoSavePreAction != null)
{
audit.Configuration.AutoSavePreAction(this, audit);
base.SaveChanges();
}
return rowAffecteds;
}
public override Task<int> SaveChangesAsync()
{
return SaveChangesAsync(CancellationToken.None);
}
public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken)
{
var audit = new Audit();
audit.PreSaveChanges(this);
var rowAffecteds = await base.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
audit.PostSaveChanges();
if (audit.Configuration.AutoSavePreAction != null)
{
audit.Configuration.AutoSavePreAction(this, audit);
await base.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
}
return rowAffecteds;
}
}
using(var ctx = new EntityContext())
{
// ... code ...
ctx.SaveChanges();
}
SQL Script (for Database First)
CREATE TABLE [dbo].[AuditEntries] (
[AuditEntryID] [int] NOT NULL IDENTITY,
[EntitySetName] [nvarchar](255),
[EntityTypeName] [nvarchar](255),
[State] [int] NOT NULL,
[StateName] [nvarchar](255),
[CreatedBy] [nvarchar](255),
[CreatedDate] [datetime] NOT NULL,
CONSTRAINT [PK_dbo.AuditEntries] PRIMARY KEY ([AuditEntryID])
)
GO
CREATE TABLE [dbo].[AuditEntryProperties] (
[AuditEntryPropertyID] [int] NOT NULL IDENTITY,
[AuditEntryID] [int] NOT NULL,
[RelationName] [nvarchar](255),
[PropertyName] [nvarchar](255),
[OldValue] [nvarchar](max),
[NewValue] [nvarchar](max),
CONSTRAINT [PK_dbo.AuditEntryProperties] PRIMARY KEY ([AuditEntryPropertyID])
)
GO
CREATE INDEX [IX_AuditEntryID] ON [dbo].[AuditEntryProperties]([AuditEntryID])
GO
ALTER TABLE [dbo].[AuditEntryProperties]
ADD CONSTRAINT [FK_dbo.AuditEntryProperties_dbo.AuditEntries_AuditEntryID]
FOREIGN KEY ([AuditEntryID])
REFERENCES [dbo].[AuditEntries] ([AuditEntryID])
ON DELETE CASCADE
GO