diff --git a/NzbDrone.Core.Test/Datastore/SQLiteMigrationHelperFixture.cs b/NzbDrone.Core.Test/Datastore/SQLiteMigrationHelperTests/AlterFixture.cs
similarity index 78%
rename from NzbDrone.Core.Test/Datastore/SQLiteMigrationHelperFixture.cs
rename to NzbDrone.Core.Test/Datastore/SQLiteMigrationHelperTests/AlterFixture.cs
index 386f63bf0..7e1510259 100644
--- a/NzbDrone.Core.Test/Datastore/SQLiteMigrationHelperFixture.cs
+++ b/NzbDrone.Core.Test/Datastore/SQLiteMigrationHelperTests/AlterFixture.cs
@@ -7,17 +7,17 @@ using NzbDrone.Core.Test.Framework;
 using NzbDrone.Core.Tv;
 using System.Linq;
 
-namespace NzbDrone.Core.Test.Datastore
+namespace NzbDrone.Core.Test.Datastore.SQLiteMigrationHelperTests
 {
     [TestFixture]
-    public class SQLiteMigrationHelperFixture : DbTest
+    public class AlterFixture : DbTest
     {
-        private SQLiteMigrationHelper _subject;
+        private SqLiteMigrationHelper _subject;
 
         [SetUp]
         public void SetUp()
         {
-            _subject = Mocker.Resolve<SQLiteMigrationHelper>();
+            _subject = Mocker.Resolve<SqLiteMigrationHelper>();
         }
 
         [Test]
@@ -37,7 +37,7 @@ namespace NzbDrone.Core.Test.Datastore
             var columns = _subject.GetColumns("Series");
             columns.Remove("Title");
 
-            _subject.CreateTable("Series_New", columns.Values, new List<SQLiteMigrationHelper.SQLiteIndex>());
+            _subject.CreateTable("Series_New", columns.Values, new List<SQLiteIndex>());
 
             var newColumns = _subject.GetColumns("Series_New");
 
@@ -106,5 +106,22 @@ namespace NzbDrone.Core.Test.Datastore
             newIndexes.Should().HaveSameCount(indexes);
             newIndexes.Select(c=>c.Column).Should().BeEquivalentTo(indexes.Select(c=>c.Column));
         }
+
+
+        [Test]
+        public void should_be_able_to_create_table_with_new_indexes()
+        {
+            var columns = _subject.GetColumns("Series");
+            columns.Remove("Title");
+
+            _subject.CreateTable("Series_New", columns.Values, new List<SQLiteIndex>{new SQLiteIndex{Column = "AirTime", Table = "Series_New", Unique = true}});
+
+            var newColumns = _subject.GetColumns("Series_New");
+            var newIndexes = _subject.GetIndexes("Series_New");
+
+            newColumns.Values.Should().HaveSameCount(columns.Values);
+            newIndexes.Should().Contain(i=>i.Column == "AirTime");
+        }
+
     }
 }
\ No newline at end of file
diff --git a/NzbDrone.Core.Test/Datastore/SQLiteMigrationHelperTests/DuplicateFixture.cs b/NzbDrone.Core.Test/Datastore/SQLiteMigrationHelperTests/DuplicateFixture.cs
new file mode 100644
index 000000000..67aefd265
--- /dev/null
+++ b/NzbDrone.Core.Test/Datastore/SQLiteMigrationHelperTests/DuplicateFixture.cs
@@ -0,0 +1,42 @@
+using System.Collections.Generic;
+using System.Linq;
+using FizzWare.NBuilder;
+using FluentAssertions;
+using NUnit.Framework;
+using NzbDrone.Core.Datastore.Migration.Framework;
+using NzbDrone.Core.Test.Framework;
+using NzbDrone.Core.Tv;
+
+namespace NzbDrone.Core.Test.Datastore.SQLiteMigrationHelperTests
+{
+    [TestFixture]
+    public class DuplicateFixture : DbTest
+    {
+        private SqLiteMigrationHelper _subject;
+
+        [SetUp]
+        public void SetUp()
+        {
+            _subject = Mocker.Resolve<SqLiteMigrationHelper>();
+        }
+
+
+        [Test]
+        public void get_duplicates()
+        {
+            var series = Builder<Series>.CreateListOfSize(10)
+                                        .Random(3)
+                                        .With(c => c.QualityProfileId = 100)
+                                        .BuildListOfNew();
+
+            Db.InsertMany(series);
+
+            var duplicates = _subject.GetDuplicates<int>("series", "QualityProfileId").ToList();
+
+
+            duplicates.Should().HaveCount(1);
+            duplicates.First().Should().HaveCount(3);
+        }
+
+    }
+}
\ No newline at end of file
diff --git a/NzbDrone.Core.Test/Framework/DbTest.cs b/NzbDrone.Core.Test/Framework/DbTest.cs
index ec94f7418..561283875 100644
--- a/NzbDrone.Core.Test/Framework/DbTest.cs
+++ b/NzbDrone.Core.Test/Framework/DbTest.cs
@@ -93,7 +93,7 @@ namespace NzbDrone.Core.Test.Framework
 
             Mocker.SetConstant<IAnnouncer>(Mocker.Resolve<MigrationLogger>());
             Mocker.SetConstant<IConnectionStringFactory>(Mocker.Resolve<ConnectionStringFactory>());
-            Mocker.SetConstant<ISQLiteMigrationHelper>(Mocker.Resolve<SQLiteMigrationHelper>());
+            Mocker.SetConstant<ISqLiteMigrationHelper>(Mocker.Resolve<SqLiteMigrationHelper>());
             Mocker.SetConstant<ISQLiteAlter>(Mocker.Resolve<SQLiteAlter>());
             Mocker.SetConstant<IMigrationController>(Mocker.Resolve<MigrationController>());
 
diff --git a/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj b/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj
index 524d84b1d..40131b5d9 100644
--- a/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj
+++ b/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj
@@ -108,7 +108,8 @@
     <Compile Include="Datastore\PagingSpecExtenstionsTests\ToSortDirectionFixture.cs" />
     <Compile Include="Datastore\PagingSpecExtenstionsTests\PagingOffsetFixture.cs" />
     <Compile Include="Datastore\ReflectionStrategyFixture\Benchmarks.cs" />
-    <Compile Include="Datastore\SQLiteMigrationHelperFixture.cs" />
+    <Compile Include="Datastore\SQLiteMigrationHelperTests\AlterFixture.cs" />
+    <Compile Include="Datastore\SQLiteMigrationHelperTests\DuplicateFixture.cs" />
     <Compile Include="DecisionEngineTests\NotRestrictedReleaseSpecificationFixture.cs" />
     <Compile Include="Download\DownloadApprovedReportsTests\DownloadApprovedFixture.cs" />
     <Compile Include="Download\DownloadApprovedReportsTests\GetQualifiedReportsFixture.cs" />
diff --git a/NzbDrone.Core/Datastore/Migration/008_remove_backlog.cs b/NzbDrone.Core/Datastore/Migration/008_remove_backlog.cs
index 6614e2c14..83fd62478 100644
--- a/NzbDrone.Core/Datastore/Migration/008_remove_backlog.cs
+++ b/NzbDrone.Core/Datastore/Migration/008_remove_backlog.cs
@@ -8,8 +8,8 @@ namespace NzbDrone.Core.Datastore.Migration
     {
         protected override void MainDbUpgrade()
         {
-            SQLiteAlter.DropColumns("Series", new[] { "BacklogSetting" });
-            SQLiteAlter.DropColumns("NamingConfig", new[] { "UseSceneName" });
+            SqLiteAlter.DropColumns("Series", new[] { "BacklogSetting" });
+            SqLiteAlter.DropColumns("NamingConfig", new[] { "UseSceneName" });
         }
     }
 }
diff --git a/NzbDrone.Core/Datastore/Migration/009_fix_renameEpisodes.cs b/NzbDrone.Core/Datastore/Migration/009_fix_renameEpisodes.cs
index d52799a03..f5ef5b2d1 100644
--- a/NzbDrone.Core/Datastore/Migration/009_fix_renameEpisodes.cs
+++ b/NzbDrone.Core/Datastore/Migration/009_fix_renameEpisodes.cs
@@ -8,7 +8,7 @@ namespace NzbDrone.Core.Datastore.Migration
     {
         protected override void MainDbUpgrade()
         {
-            SQLiteAlter.DropColumns("NamingConfig", new[] { "SeasonFolderFormat" });
+            SqLiteAlter.DropColumns("NamingConfig", new[] { "SeasonFolderFormat" });
 
             Execute.Sql("UPDATE NamingConfig SET RenameEpisodes = 1 WHERE RenameEpisodes = -1");
             Execute.Sql("UPDATE NamingConfig SET RenameEpisodes = 0 WHERE RenameEpisodes = -2");
diff --git a/NzbDrone.Core/Datastore/Migration/011_remove_ignored.cs b/NzbDrone.Core/Datastore/Migration/011_remove_ignored.cs
index 103f0648a..8f62c3b46 100644
--- a/NzbDrone.Core/Datastore/Migration/011_remove_ignored.cs
+++ b/NzbDrone.Core/Datastore/Migration/011_remove_ignored.cs
@@ -8,8 +8,8 @@ namespace NzbDrone.Core.Datastore.Migration
     {
         protected override void MainDbUpgrade()
         {
-            SQLiteAlter.DropColumns("Episodes", new[] { "Ignored" });
-            SQLiteAlter.DropColumns("Seasons", new[] { "Ignored" });
+            SqLiteAlter.DropColumns("Episodes", new[] { "Ignored" });
+            SqLiteAlter.DropColumns("Seasons", new[] { "Ignored" });
         }
     }
 }
diff --git a/NzbDrone.Core/Datastore/Migration/012_remove_custom_start_date.cs b/NzbDrone.Core/Datastore/Migration/012_remove_custom_start_date.cs
index 417e73013..a7f156c87 100644
--- a/NzbDrone.Core/Datastore/Migration/012_remove_custom_start_date.cs
+++ b/NzbDrone.Core/Datastore/Migration/012_remove_custom_start_date.cs
@@ -8,7 +8,7 @@ namespace NzbDrone.Core.Datastore.Migration
     {
         protected override void MainDbUpgrade()
         {
-            SQLiteAlter.DropColumns("Series", new[] { "CustomStartDate" });
+            SqLiteAlter.DropColumns("Series", new[] { "CustomStartDate" });
         }
     }
 }
diff --git a/NzbDrone.Core/Datastore/Migration/014_drop_air_date.cs b/NzbDrone.Core/Datastore/Migration/014_drop_air_date.cs
index 434ccc8a2..b88282202 100644
--- a/NzbDrone.Core/Datastore/Migration/014_drop_air_date.cs
+++ b/NzbDrone.Core/Datastore/Migration/014_drop_air_date.cs
@@ -8,7 +8,7 @@ namespace NzbDrone.Core.Datastore.Migration
     {
         protected override void MainDbUpgrade()
         {
-            SQLiteAlter.DropColumns("Episodes", new []{ "AirDate" });
+            SqLiteAlter.DropColumns("Episodes", new []{ "AirDate" });
         }
     }
 }
diff --git a/NzbDrone.Core/Datastore/Migration/018_remove_duplicates.cs b/NzbDrone.Core/Datastore/Migration/018_remove_duplicates.cs
new file mode 100644
index 000000000..379f79a43
--- /dev/null
+++ b/NzbDrone.Core/Datastore/Migration/018_remove_duplicates.cs
@@ -0,0 +1,60 @@
+using FluentMigrator;
+using NzbDrone.Core.Datastore.Migration.Framework;
+using System.Linq;
+
+namespace NzbDrone.Core.Datastore.Migration
+{
+    [Migration(18)]
+    public class remove_duplicates : NzbDroneMigrationBase
+    {
+        protected override void MainDbUpgrade()
+        {
+            using (var transaction = MigrationHelper.BeginTransaction())
+            {
+                RemoveDuplicateSeries("TvdbId");
+                RemoveDuplicateSeries("TitleSlug");
+
+                var duplicatedEpisodes = MigrationHelper.GetDuplicates<int>("Episodes", "TvDbEpisodeId");
+
+                foreach (var duplicate in duplicatedEpisodes)
+                {
+                    foreach (var episodeId in duplicate.OrderBy(c => c.Key).Skip(1).Select(c => c.Key))
+                    {
+                        RemoveEpisodeRows(episodeId);
+                    }
+                }
+
+                transaction.Commit();
+            }
+        }
+
+        private void RemoveDuplicateSeries(string field)
+        {
+            var duplicatedSeries = MigrationHelper.GetDuplicates<int>("Series", field);
+
+            foreach (var duplicate in duplicatedSeries)
+            {
+                foreach (var seriesId in duplicate.OrderBy(c => c.Key).Skip(1).Select(c => c.Key))
+                {
+                    RemoveSeriesRows(seriesId);
+                }
+            }
+        }
+
+        private void RemoveSeriesRows(int seriesId)
+        {
+            MigrationHelper.ExecuteNonQuery("DELETE FROM Series WHERE Id = {0}", seriesId.ToString());
+            MigrationHelper.ExecuteNonQuery("DELETE FROM Episodes WHERE SeriesId = {0}", seriesId.ToString());
+            MigrationHelper.ExecuteNonQuery("DELETE FROM Seasons WHERE SeriesId = {0}", seriesId.ToString());
+            MigrationHelper.ExecuteNonQuery("DELETE FROM History WHERE SeriesId = {0}", seriesId.ToString());
+            MigrationHelper.ExecuteNonQuery("DELETE FROM EpisodeFiles WHERE SeriesId = {0}", seriesId.ToString());
+        }
+
+        private void RemoveEpisodeRows(int episodeId)
+        {
+            MigrationHelper.ExecuteNonQuery("DELETE FROM Episodes WHERE Id = {0}", episodeId.ToString());
+            MigrationHelper.ExecuteNonQuery("DELETE FROM History WHERE EpisodeId = {0}", episodeId.ToString());
+        }
+
+    }
+}
diff --git a/NzbDrone.Core/Datastore/Migration/019_restore_unique_constraints.cs b/NzbDrone.Core/Datastore/Migration/019_restore_unique_constraints.cs
new file mode 100644
index 000000000..c4e304df7
--- /dev/null
+++ b/NzbDrone.Core/Datastore/Migration/019_restore_unique_constraints.cs
@@ -0,0 +1,20 @@
+using FluentMigrator;
+using NzbDrone.Core.Datastore.Migration.Framework;
+
+namespace NzbDrone.Core.Datastore.Migration
+{
+    [Migration(19)]
+    public class restore_unique_constraints : NzbDroneMigrationBase
+    {
+        protected override void MainDbUpgrade()
+        {
+            SqLiteAlter.AddIndexes("Series", 
+                new SQLiteIndex { Column = "TvdbId", Table = "Series", Unique = true },
+                new SQLiteIndex { Column = "TitleSlug", Table = "Series", Unique = true });
+
+            SqLiteAlter.AddIndexes("Episodes", 
+                new SQLiteIndex { Column = "TvDbEpisodeId", Table = "Episodes", Unique = true });
+        }
+
+    }
+}
diff --git a/NzbDrone.Core/Datastore/Migration/Framework/MigrationContext.cs b/NzbDrone.Core/Datastore/Migration/Framework/MigrationContext.cs
index ebf634c15..90ac77a1e 100644
--- a/NzbDrone.Core/Datastore/Migration/Framework/MigrationContext.cs
+++ b/NzbDrone.Core/Datastore/Migration/Framework/MigrationContext.cs
@@ -4,5 +4,6 @@
     {
         public MigrationType MigrationType { get; set; }
         public ISQLiteAlter SQLiteAlter { get; set; }
+        public ISqLiteMigrationHelper MigrationHelper { get; set; }
     }
 }
\ No newline at end of file
diff --git a/NzbDrone.Core/Datastore/Migration/Framework/MigrationController.cs b/NzbDrone.Core/Datastore/Migration/Framework/MigrationController.cs
index e2a0480f2..a930511c3 100644
--- a/NzbDrone.Core/Datastore/Migration/Framework/MigrationController.cs
+++ b/NzbDrone.Core/Datastore/Migration/Framework/MigrationController.cs
@@ -15,13 +15,15 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
     {
         private readonly IAnnouncer _announcer;
         private readonly ISQLiteAlter _sqLiteAlter;
+        private readonly ISqLiteMigrationHelper _migrationHelper;
 
         private static readonly HashSet<string> MigrationCache = new HashSet<string>();
 
-        public MigrationController(IAnnouncer announcer, ISQLiteAlter sqLiteAlter)
+        public MigrationController(IAnnouncer announcer, ISQLiteAlter sqLiteAlter, ISqLiteMigrationHelper migrationHelper)
         {
             _announcer = announcer;
             _sqLiteAlter = sqLiteAlter;
+            _migrationHelper = migrationHelper;
         }
 
         public void MigrateToLatest(string connectionString, MigrationType migrationType)
@@ -40,7 +42,8 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
                         ApplicationContext = new MigrationContext
                             {
                                 MigrationType = migrationType,
-                                SQLiteAlter = _sqLiteAlter
+                                SQLiteAlter = _sqLiteAlter,
+                                MigrationHelper = _migrationHelper,
                             }
                     };
 
diff --git a/NzbDrone.Core/Datastore/Migration/Framework/NzbDroneMigrationBase.cs b/NzbDrone.Core/Datastore/Migration/Framework/NzbDroneMigrationBase.cs
index a1be291fe..da9dde57a 100644
--- a/NzbDrone.Core/Datastore/Migration/Framework/NzbDroneMigrationBase.cs
+++ b/NzbDrone.Core/Datastore/Migration/Framework/NzbDroneMigrationBase.cs
@@ -1,9 +1,18 @@
 using System;
+using NLog;
+using NzbDrone.Common.Instrumentation;
 
 namespace NzbDrone.Core.Datastore.Migration.Framework
 {
     public abstract class NzbDroneMigrationBase : FluentMigrator.Migration
     {
+        private Logger _logger;
+
+        protected NzbDroneMigrationBase()
+        {
+            _logger = NzbDroneLogger.GetLogger();
+        }
+
         protected virtual void MainDbUpgrade()
         {
         }
@@ -16,7 +25,8 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
         {
             var context = (MigrationContext)ApplicationContext;
 
-            SQLiteAlter = context.SQLiteAlter;
+            SqLiteAlter = context.SQLiteAlter;
+            MigrationHelper = context.MigrationHelper;
 
             switch (context.MigrationType)
             {
@@ -33,7 +43,8 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
             }
         }
 
-        protected ISQLiteAlter SQLiteAlter { get; private set; }
+        protected ISQLiteAlter SqLiteAlter { get; private set; }
+        protected ISqLiteMigrationHelper MigrationHelper { get; private set; }
 
         public override void Down()
         {
diff --git a/NzbDrone.Core/Datastore/Migration/Framework/SQLiteColumn.cs b/NzbDrone.Core/Datastore/Migration/Framework/SQLiteColumn.cs
new file mode 100644
index 000000000..976916885
--- /dev/null
+++ b/NzbDrone.Core/Datastore/Migration/Framework/SQLiteColumn.cs
@@ -0,0 +1,13 @@
+namespace NzbDrone.Core.Datastore.Migration.Framework
+{
+    public class SQLiteColumn
+    {
+        public string Name { get; set; }
+        public string Schema { get; set; }
+
+        public override string ToString()
+        {
+            return string.Format("[{0}] {1}", Name, Schema);
+        }
+    }
+}
\ No newline at end of file
diff --git a/NzbDrone.Core/Datastore/Migration/Framework/SQLiteIndex.cs b/NzbDrone.Core/Datastore/Migration/Framework/SQLiteIndex.cs
new file mode 100644
index 000000000..cbf18dbd9
--- /dev/null
+++ b/NzbDrone.Core/Datastore/Migration/Framework/SQLiteIndex.cs
@@ -0,0 +1,39 @@
+using System;
+
+namespace NzbDrone.Core.Datastore.Migration.Framework
+{
+    public class SQLiteIndex : IEquatable<SQLiteIndex>
+    {
+        public string Column { get; set; }
+        public string Table { get; set; }
+        public bool Unique { get; set; }
+
+        public bool Equals(SQLiteIndex other)
+        {
+            return IndexName == other.IndexName;
+        }
+
+        public override int GetHashCode()
+        {
+            return IndexName.GetHashCode();
+        }
+
+        public override string ToString()
+        {
+            return string.Format("[{0}] Unique: {1}", Column, Unique);
+        }
+
+        public string IndexName
+        {
+            get
+            {
+                return string.Format("IX_{0}_{1}", Table, Column);
+            }
+        }
+
+        public string CreateSql(string tableName)
+        {
+            return string.Format(@"CREATE UNIQUE INDEX ""{2}"" ON ""{0}"" (""{1}"" ASC)", tableName, Column, IndexName);
+        }
+    }
+}
\ No newline at end of file
diff --git a/NzbDrone.Core/Datastore/Migration/Framework/SQLiteMigrationHelper.cs b/NzbDrone.Core/Datastore/Migration/Framework/SQLiteMigrationHelper.cs
index 3813c0e79..843b97466 100644
--- a/NzbDrone.Core/Datastore/Migration/Framework/SQLiteMigrationHelper.cs
+++ b/NzbDrone.Core/Datastore/Migration/Framework/SQLiteMigrationHelper.cs
@@ -7,18 +7,21 @@ using NLog;
 
 namespace NzbDrone.Core.Datastore.Migration.Framework
 {
-    public interface ISQLiteMigrationHelper
+    public interface ISqLiteMigrationHelper
     {
-        Dictionary<String, SQLiteMigrationHelper.SQLiteColumn> GetColumns(string tableName);
-        void CreateTable(string tableName, IEnumerable<SQLiteMigrationHelper.SQLiteColumn> values, IEnumerable<SQLiteMigrationHelper.SQLiteIndex> indexes);
-        void CopyData(string sourceTable, string destinationTable, IEnumerable<SQLiteMigrationHelper.SQLiteColumn> columns);
+        Dictionary<String, SQLiteColumn> GetColumns(string tableName);
+        void CreateTable(string tableName, IEnumerable<SQLiteColumn> values, IEnumerable<SQLiteIndex> indexes);
+        void CopyData(string sourceTable, string destinationTable, IEnumerable<SQLiteColumn> columns);
         void DropTable(string tableName);
         void RenameTable(string tableName, string newName);
+        IEnumerable<IGrouping<T, KeyValuePair<int, T>>> GetDuplicates<T>(string tableName, string columnName);
         SQLiteTransaction BeginTransaction();
-        List<SQLiteMigrationHelper.SQLiteIndex> GetIndexes(string tableName);
+        List<SQLiteIndex> GetIndexes(string tableName);
+        int ExecuteScalar(string command, params string[] args);
+        void ExecuteNonQuery(string command, params string[] args);
     }
 
-    public class SQLiteMigrationHelper : ISQLiteMigrationHelper
+    public class SqLiteMigrationHelper : ISqLiteMigrationHelper
     {
         private readonly SQLiteConnection _connection;
 
@@ -28,7 +31,7 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
         private static readonly Regex IndexRegex = new Regex(@"\(""(?<col>.*)""\s(?<direction>ASC|DESC)\)$",
              RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Multiline);
 
-        public SQLiteMigrationHelper(IConnectionStringFactory connectionStringFactory, Logger logger)
+        public SqLiteMigrationHelper(IConnectionStringFactory connectionStringFactory, Logger logger)
         {
             try
             {
@@ -69,18 +72,22 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
                                    });
         }
 
+
+        private static IEnumerable<T> ReadArray<T>(SQLiteDataReader reader)
+        {
+            while (reader.Read())
+            {
+                yield return (T)Convert.ChangeType(reader[0], typeof(T));
+            }
+        }
+
         public List<SQLiteIndex> GetIndexes(string tableName)
         {
             var command = new SQLiteCommand(string.Format("SELECT sql FROM sqlite_master WHERE type='index' AND tbl_name ='{0}'", tableName));
             command.Connection = _connection;
 
             var reader = command.ExecuteReader();
-            var sqls = new List<string>();
-
-            while (reader.Read())
-            {
-                sqls.Add(reader[0].ToString());
-            }
+            var sqls = ReadArray<string>(reader).ToList();
 
 
             var indexes = new List<SQLiteIndex>();
@@ -108,7 +115,7 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
 
             foreach (var index in indexes)
             {
-                ExecuteNonQuery("DROP INDEX {0}", index.IndexName);
+                ExecuteNonQuery("DROP INDEX IF EXISTS {0}", index.IndexName);
                 ExecuteNonQuery(index.CreateSql(tableName));
             }
         }
@@ -146,6 +153,23 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
             renameCommand.ExecuteNonQuery();
         }
 
+        public IEnumerable<IGrouping<T, KeyValuePair<int, T>>> GetDuplicates<T>(string tableName, string columnName)
+        {
+            var getDuplicates = BuildCommand("select id, {0} from {1}", columnName, tableName);
+
+            var result = new List<KeyValuePair<int, T>>();
+
+            using (var reader = getDuplicates.ExecuteReader())
+            {
+                while (reader.Read())
+                {
+                    result.Add(new KeyValuePair<int, T>(reader.GetInt16(0), (T)Convert.ChangeType(reader[1], typeof(T))));
+                }
+            }
+
+            return result.GroupBy(c => c.Value).Where(g => g.Count() > 1);
+        }
+
         public int GetRowCount(string tableName)
         {
             var countCommand = BuildCommand("SELECT COUNT(*) FROM {0};", tableName);
@@ -166,8 +190,7 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
         }
 
 
-
-        private void ExecuteNonQuery(string command, params string[] args)
+        public void ExecuteNonQuery(string command, params string[] args)
         {
             var sqLiteCommand = new SQLiteCommand(string.Format(command, args))
             {
@@ -177,43 +200,17 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
             sqLiteCommand.ExecuteNonQuery();
         }
 
-
-        public class SQLiteColumn
+        public int ExecuteScalar(string command, params string[] args)
         {
-            public string Name { get; set; }
-            public string Schema { get; set; }
-
-            public override string ToString()
+            var sqLiteCommand = new SQLiteCommand(string.Format(command, args))
             {
-                return string.Format("[{0}] {1}", Name, Schema);
-            }
+                Connection = _connection
+            };
+
+           return (int)sqLiteCommand.ExecuteScalar();
         }
 
-        public class SQLiteIndex
-        {
-            public string Column { get; set; }
-            public string Table { get; set; }
-            public bool Unique { get; set; }
 
-            public override string ToString()
-            {
-                return string.Format("[{0}] Unique: {1}", Column, Unique);
-            }
-
-            public string IndexName
-            {
-                get
-                {
-                    return string.Format("IX_{0}_{1}", Table, Column);
-                }
-            }
-
-            public string CreateSql(string tableName)
-            {
-                return string.Format(@"CREATE UNIQUE INDEX ""{2}"" ON ""{0}"" (""{1}"" ASC)", tableName, Column, IndexName);
-            }
-        }
+       
     }
-
-
 }
\ No newline at end of file
diff --git a/NzbDrone.Core/Datastore/Migration/Framework/SqliteAlter.cs b/NzbDrone.Core/Datastore/Migration/Framework/SqliteAlter.cs
index 572b0c493..c22670588 100644
--- a/NzbDrone.Core/Datastore/Migration/Framework/SqliteAlter.cs
+++ b/NzbDrone.Core/Datastore/Migration/Framework/SqliteAlter.cs
@@ -6,13 +6,14 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
     public interface ISQLiteAlter
     {
         void DropColumns(string tableName, IEnumerable<string> columns);
+        void AddIndexes(string tableName, params SQLiteIndex[] indexes);
     }
 
     public class SQLiteAlter : ISQLiteAlter
     {
-        private readonly ISQLiteMigrationHelper _sqLiteMigrationHelper;
+        private readonly ISqLiteMigrationHelper _sqLiteMigrationHelper;
 
-        public SQLiteAlter(ISQLiteMigrationHelper sqLiteMigrationHelper)
+        public SQLiteAlter(ISqLiteMigrationHelper sqLiteMigrationHelper)
         {
             _sqLiteMigrationHelper = sqLiteMigrationHelper;
         }
@@ -27,18 +28,39 @@ namespace NzbDrone.Core.Datastore.Migration.Framework
                 var newColumns = originalColumns.Where(c => !columns.Contains(c.Key)).Select(c => c.Value).ToList();
                 var newIndexes = originalIndexes.Where(c => !columns.Contains(c.Column));
 
-                var tempTableName = tableName + "_temp";
-
-                _sqLiteMigrationHelper.CreateTable(tempTableName, newColumns, newIndexes);
-
-                _sqLiteMigrationHelper.CopyData(tableName, tempTableName, newColumns);
-
-                _sqLiteMigrationHelper.DropTable(tableName);
-
-                _sqLiteMigrationHelper.RenameTable(tempTableName, tableName);
+                CreateTable(tableName, newColumns, newIndexes);
 
                 transaction.Commit();
             }
         }
+
+        public void AddIndexes(string tableName, params SQLiteIndex[] indexes)
+        {
+            using (var transaction = _sqLiteMigrationHelper.BeginTransaction())
+            {
+                var columns = _sqLiteMigrationHelper.GetColumns(tableName).Select(c => c.Value).ToList();
+                var originalIndexes = _sqLiteMigrationHelper.GetIndexes(tableName);
+
+                var newIndexes = originalIndexes.Union(indexes);
+
+
+                CreateTable(tableName, columns, newIndexes);
+
+                transaction.Commit();
+            }
+        }
+
+        private void CreateTable(string tableName, List<SQLiteColumn> newColumns, IEnumerable<SQLiteIndex> newIndexes)
+        {
+            var tempTableName = tableName + "_temp";
+
+            _sqLiteMigrationHelper.CreateTable(tempTableName, newColumns, newIndexes);
+
+            _sqLiteMigrationHelper.CopyData(tableName, tempTableName, newColumns);
+
+            _sqLiteMigrationHelper.DropTable(tableName);
+
+            _sqLiteMigrationHelper.RenameTable(tempTableName, tableName);
+        }
     }
 }
\ No newline at end of file
diff --git a/NzbDrone.Core/NzbDrone.Core.csproj b/NzbDrone.Core/NzbDrone.Core.csproj
index 2f39373e1..d15de6be0 100644
--- a/NzbDrone.Core/NzbDrone.Core.csproj
+++ b/NzbDrone.Core/NzbDrone.Core.csproj
@@ -160,6 +160,8 @@
     <Compile Include="Datastore\Migration\015_add_air_date_as_string.cs" />
     <Compile Include="Datastore\Migration\016_updated_imported_history_item.cs" />
     <Compile Include="Datastore\Migration\017_reset_scene_names.cs" />
+    <Compile Include="Datastore\Migration\018_remove_duplicates.cs" />
+    <Compile Include="Datastore\Migration\019_restore_unique_constraints.cs" />
     <Compile Include="Datastore\Migration\Framework\MigrationContext.cs" />
     <Compile Include="Datastore\Migration\Framework\MigrationController.cs" />
     <Compile Include="Datastore\Migration\Framework\MigrationExtension.cs" />
@@ -169,6 +171,8 @@
     <Compile Include="Datastore\Migration\Framework\NzbDroneMigrationBase.cs" />
     <Compile Include="Datastore\MigrationType.cs" />
     <Compile Include="Datastore\Migration\Framework\SQLiteAlter.cs" />
+    <Compile Include="Datastore\Migration\Framework\SQLiteColumn.cs" />
+    <Compile Include="Datastore\Migration\Framework\SQLiteIndex.cs" />
     <Compile Include="Datastore\Migration\Framework\SQLiteMigrationHelper.cs" />
     <Compile Include="Datastore\ModelBase.cs" />
     <Compile Include="Datastore\BasicRepository.cs" />