initial commit

App_Code/Data Access Layer/Shared/DatabaseObjects.vb

@@ -0,0 +1,80 @@
+Imports BaseClasses
+Imports BaseClasses.Data
+Imports System.Text.RegularExpressions
+
+
+''' <summary>
+''' The DatabaseObjects class contains a set of functions that provide
+''' access to the database by using table or field names.  The class
+''' allows conversion of names into the proper table object and
+''' retrieval of values for field name.
+''' </summary>
+''' <remarks></remarks>
+Public Class DatabaseObjects
+
+    Private Const ASSEMBLY_NAME As String = "App_Code"
+    Private Const BUSINESS_NAMESPACE As String = "Persons.Business"
+
+
+    ''' <summary>
+    ''' Returns the BaseTable object for the given table name.
+    ''' Determines if this is a Table, View or Query - and then
+    ''' calls GetType to retrieve and return the object.
+    ''' </summary>
+    ''' <param name="tableName">tableName whose object is desired</param>
+    ''' <returns>A BaseTable object for the given table name.</returns>
+    Public Shared Function GetTableObject(ByVal tableName As String) As BaseTable
+        Dim expandedTableName As String = String.Empty
+        Dim TYPE_FORMAT As String = "{0}.{1}{2},{3}"
+
+        Dim rgx As Regex = new Regex("[^a-zA-Z0-9]")
+        tableName = rgx.Replace(tableName, "_")
+
+        ' First see if it is a table.
+        Try
+            expandedTableName = String.Format(TYPE_FORMAT, BUSINESS_NAMESPACE, tableName, "Table", ASSEMBLY_NAME)
+            Type.GetType(expandedTableName, True, True)
+        Catch
+            ' It was not really a table name - so reset and try again with a view or a query.
+            expandedTableName = String.Empty
+        End Try
+
+        ' Check if it is a view.
+        If expandedTableName = String.Empty Then
+            Try
+                expandedTableName = String.Format(TYPE_FORMAT, BUSINESS_NAMESPACE, tableName, "View", ASSEMBLY_NAME)
+                Type.GetType(expandedTableName, True, True)
+            Catch
+                ' It was not really a view name - so reset and try again with a query.
+                expandedTableName = String.Empty
+            End Try
+        End If
+
+
+        ' Check if it is a query.
+        If expandedTableName = String.Empty Then
+            Try
+                expandedTableName = String.Format(TYPE_FORMAT, BUSINESS_NAMESPACE, tableName, "Query", ASSEMBLY_NAME)
+                Type.GetType(expandedTableName, True, True)
+            Catch
+                ' Still no luck.
+                expandedTableName = String.Empty
+            End Try
+        End If
+
+
+        If expandedTableName <> String.Empty Then
+            ' OK, looks like we found an object.
+            Try
+                Dim t As BaseTable = BaseTable.CreateInstance(expandedTableName)
+                Return t
+            Catch
+                ' Ignore, fall through and return Nothing
+            End Try
+        End If
+
+        ' Could not find a table.
+        Return Nothing
+    End Function
+
+End Class