diff --git a/Apps/YY.EventLogExportToPostgreSQL/Program.cs b/Apps/YY.EventLogExportToPostgreSQL/Program.cs
index 03bb8a8..f54cbfa 100644
--- a/Apps/YY.EventLogExportToPostgreSQL/Program.cs
+++ b/Apps/YY.EventLogExportToPostgreSQL/Program.cs
@@ -1,10 +1,7 @@
 using System;
-using YY.EventLogReaderAssistant;
 using YY.EventLogExportAssistant;
 using YY.EventLogExportAssistant.PostgreSQL;
-using System.Linq;
 using Microsoft.EntityFrameworkCore;
-using System.Threading.Tasks;
 using System.Threading;
 using Microsoft.Extensions.Configuration;
 
diff --git a/Apps/YY.EventLogExportToSQLServer/Program.cs b/Apps/YY.EventLogExportToSQLServer/Program.cs
index 81b970f..1a395b3 100644
--- a/Apps/YY.EventLogExportToSQLServer/Program.cs
+++ b/Apps/YY.EventLogExportToSQLServer/Program.cs
@@ -1,12 +1,9 @@
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Configuration;
 using System;
-using System.Linq;
 using System.Threading;
 using YY.EventLogExportAssistant;
 using YY.EventLogExportAssistant.SQLServer;
-using YY.EventLogExportAssistant.SQLServer.Models;
-using YY.EventLogReaderAssistant;
 
 namespace YY.EventLogExportToSQLServer
 {
diff --git a/Libs/YY.EventLogExportAssistant.Core/EventLogExportMaster.cs b/Libs/YY.EventLogExportAssistant.Core/EventLogExportMaster.cs
index 9701c80..71c36c4 100644
--- a/Libs/YY.EventLogExportAssistant.Core/EventLogExportMaster.cs
+++ b/Libs/YY.EventLogExportAssistant.Core/EventLogExportMaster.cs
@@ -1,9 +1,7 @@
-using System;
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.IO;
 using YY.EventLogReaderAssistant;
 using YY.EventLogReaderAssistant.Models;
-using System.Timers;
 
 namespace YY.EventLogExportAssistant
 {
@@ -158,19 +156,23 @@ namespace YY.EventLogExportAssistant
         {
             if (_referenceDataHash != reader.ReferencesHash)
             {
-                List<Severity> severities = new List<Severity>();
-                severities.Add(Severity.Error);
-                severities.Add(Severity.Information);
-                severities.Add(Severity.Note);
-                severities.Add(Severity.Unknown);
-                severities.Add(Severity.Warning);
+                List<Severity> severities = new List<Severity>
+                {
+                    Severity.Error,
+                    Severity.Information,
+                    Severity.Note,
+                    Severity.Unknown,
+                    Severity.Warning
+                };
 
-                List<TransactionStatus> transactionStatuses = new List<TransactionStatus>();
-                transactionStatuses.Add(TransactionStatus.Committed);
-                transactionStatuses.Add(TransactionStatus.NotApplicable);
-                transactionStatuses.Add(TransactionStatus.RolledBack);
-                transactionStatuses.Add(TransactionStatus.Unfinished);
-                transactionStatuses.Add(TransactionStatus.Unknown);
+                List<TransactionStatus> transactionStatuses = new List<TransactionStatus>
+                {
+                    TransactionStatus.Committed,
+                    TransactionStatus.NotApplicable,
+                    TransactionStatus.RolledBack,
+                    TransactionStatus.Unfinished,
+                    TransactionStatus.Unknown
+                };
 
                 ReferencesData data = new ReferencesData()
                 {
diff --git a/Libs/YY.EventLogExportAssistant.PostgreSQL/EventLogContext.cs b/Libs/YY.EventLogExportAssistant.PostgreSQL/EventLogContext.cs
index 3ba00d1..0cba3ea 100644
--- a/Libs/YY.EventLogExportAssistant.PostgreSQL/EventLogContext.cs
+++ b/Libs/YY.EventLogExportAssistant.PostgreSQL/EventLogContext.cs
@@ -1,9 +1,5 @@
 using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.Extensions.Configuration;
-using System;
-using System.Collections.Generic;
-using System.Text;
 using YY.EventLogExportAssistant.PostgreSQL.Models;
 
 namespace YY.EventLogExportAssistant.PostgreSQL