Added support for aggregate function expressions. Closes #50.

DatabaseObjects.vbproj

@@ -190,6 +190,7 @@
     <Compile Include="Misc\AssemblyInfo.vb" />
     <Compile Include="SQL\Amend\SQLInsertFromSelect.vb" />
     <Compile Include="SQL\Amend\SQLUpdateField.vb" />
+    <Compile Include="SQL\Expressions\SQLAggregateExpression.vb" />
     <Compile Include="SQL\Expressions\SQLAllFieldsExpression.vb" />
     <Compile Include="SQL\Expressions\SQLRightFunctionExpression.vb" />
     <Compile Include="SQL\Expressions\SQLArithmeticExpression.vb" />

SQL/Expressions/SQLAggregateExpression.vb

@@ -0,0 +1,33 @@
+
+' ___________________________________________________
+'
+'  © Hi-Integrity Systems 2012. All rights reserved.
+'  www.hisystems.com.au - Toby Wicks
+' ___________________________________________________
+'
+
+Option Strict On
+Option Explicit On
+
+Namespace SQL
+
+    Public Class SQLAggregateExpression
+        Inherits SQLFunctionExpression
+
+        Public Sub New(ByVal aggregate As AggregateFunction, ByVal fieldName As String)
+
+            Me.New(aggregate, New SQLFieldExpression(fieldName))
+
+        End Sub
+
+        Public Sub New(ByVal aggregate As AggregateFunction, ByVal expression As SQLExpression)
+
+            MyBase.New(Misc.SQLConvertAggregate(aggregate), expression)
+
+        End Sub
+
+    End Class
+
+End Namespace
+
+