diff --git a/Common/UploadManager.cs b/Common/UploadManager.cs
index 666c0a7..426cdf4 100644
--- a/Common/UploadManager.cs
+++ b/Common/UploadManager.cs
@@ -105,9 +105,8 @@ namespace FLocal.Common {
 						Config.instance.mainConnection.LoadIdsByConditions(
 							Upload.TableSpec.instance,
 							condition,
-							Diapasone.unlimited,
-							new JoinSpec[0]
-						)[0]
+							Diapasone.unlimited
+						).Single()
 					)
 				);
 			}
diff --git a/Common/dataobjects/Account.cs b/Common/dataobjects/Account.cs
index 57b4f6f..fe54d0b 100644
--- a/Common/dataobjects/Account.cs
+++ b/Common/dataobjects/Account.cs
@@ -81,8 +81,7 @@ namespace FLocal.Common.dataobjects {
 								ComparisonType.EQUAL,
 								name
 							),
-							Diapasone.unlimited,
-							new JoinSpec[0]
+							Diapasone.unlimited
 						);
 						if(ids.Count > 1) {
 							throw new CriticalException("not unique");
diff --git a/Common/dataobjects/AccountIndicator.cs b/Common/dataobjects/AccountIndicator.cs
index 4c2c7c2..fc20457 100644
--- a/Common/dataobjects/AccountIndicator.cs
+++ b/Common/dataobjects/AccountIndicator.cs
@@ -72,8 +72,7 @@ namespace FLocal.Common.dataobjects {
 								ComparisonType.EQUAL,
 								account.id.ToString()
 							),
-							Diapasone.unlimited,
-							new JoinSpec[0]
+							Diapasone.unlimited
 						);
 						if(ids.Count > 1) {
 							throw new CriticalException("not unique");
diff --git a/Common/dataobjects/AccountSettings.cs b/Common/dataobjects/AccountSettings.cs
index 9864dc8..1eb289e 100644
--- a/Common/dataobjects/AccountSettings.cs
+++ b/Common/dataobjects/AccountSettings.cs
@@ -118,8 +118,7 @@ namespace FLocal.Common.dataobjects {
 								ComparisonType.EQUAL,
 								account.id.ToString()
 							),
-							Diapasone.unlimited,
-							new JoinSpec[0]
+							Diapasone.unlimited
 						);
 						if(ids.Count > 1) {
 							throw new CriticalException("not unique");
diff --git a/Common/dataobjects/Board.cs b/Common/dataobjects/Board.cs
index df0b19c..08abe09 100644
--- a/Common/dataobjects/Board.cs
+++ b/Common/dataobjects/Board.cs
@@ -156,8 +156,7 @@ namespace FLocal.Common.dataobjects {
 									FLocal.Core.DB.conditions.ComparisonType.EQUAL,
 									this.id.ToString()
 								),
-								Diapasone.unlimited,
-								new JoinSpec[0]
+								Diapasone.unlimited
 							) select int.Parse(stringId);
 							Board.LoadByIds(ids);
 							return ids;
diff --git a/Common/dataobjects/Category.cs b/Common/dataobjects/Category.cs
index a7e0368..5a07c9c 100644
--- a/Common/dataobjects/Category.cs
+++ b/Common/dataobjects/Category.cs
@@ -54,8 +54,7 @@ namespace FLocal.Common.dataobjects {
 							IEnumerable<int> ids = from stringId in Config.instance.mainConnection.LoadIdsByConditions(
 								TableSpec.instance,
 								new FLocal.Core.DB.conditions.EmptyCondition(),
-								Diapasone.unlimited,
-								new JoinSpec[0]
+								Diapasone.unlimited
 							) select int.Parse(stringId);
 							Category.LoadByIds(ids);
 							return ids;
@@ -84,8 +83,7 @@ namespace FLocal.Common.dataobjects {
 									FLocal.Core.DB.conditions.ComparisonType.EQUAL,
 									this.id.ToString()
 								),
-								Diapasone.unlimited,
-								new JoinSpec[0]
+								Diapasone.unlimited
 							) select int.Parse(stringId);
 							Board.LoadByIds(ids);
 							return ids;
diff --git a/Common/dataobjects/User.cs b/Common/dataobjects/User.cs
index 7220abc..37c3e16 100644
--- a/Common/dataobjects/User.cs
+++ b/Common/dataobjects/User.cs
@@ -133,8 +133,7 @@ namespace FLocal.Common.dataobjects {
 								ComparisonType.EQUAL,
 								name
 							),
-							Diapasone.unlimited,
-							new JoinSpec[0]
+							Diapasone.unlimited
 						);
 						if(ids.Count > 1) {
 							throw new CriticalException("not unique");
diff --git a/Core/DB/JoinSpec.cs b/Core/DB/JoinSpec.cs
index 65dc034..0cf903c 100644
--- a/Core/DB/JoinSpec.cs
+++ b/Core/DB/JoinSpec.cs
@@ -6,13 +6,32 @@ using System.Text;
 namespace FLocal.Core.DB {
 	public class JoinSpec {
 
+		private class TableSpec : ITableSpec {
+			private readonly string _name;
+			public TableSpec(string name) {
+				this._name = name;
+			}
+			public string name {
+				get {
+					return this._name;
+				}
+			}
+			public string idName {
+				get {
+					throw new NotImplementedException();
+				}
+			}
+		}
+
 		public readonly ColumnSpec mainColumn;
 
 		public readonly ITableSpec additionalTable;
+		public readonly ITableSpec additionalTableJoin;
 
-		public JoinSpec(ColumnSpec mainColumn, ITableSpec additionalTable) {
+		public JoinSpec(ColumnSpec mainColumn, ITableSpec additionalTable, string alias) {
 			this.mainColumn = mainColumn;
-			this.additionalTable = additionalTable;
+			this.additionalTableJoin = additionalTable;
+			this.additionalTable = new TableSpec(alias);
 		}
 
 	}