EDMI: Add 3-tier database access in DatabaseWithFallback, add client config,

EDMI Service: Version 2.4.0.0
EDMI: API: Version 1.4.0.0

Service.EDMIService/Methods/Database/GetDatatableFromCache/GetDatatableFromCacheMethod.vb

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+Imports DigitalData.Modules.Database
+Imports DigitalData.Modules.Language
+Imports DigitalData.Modules.Logging
+
+Namespace Methods.Database.GetDatatableFromCache
+    Public Class GetDatatableFromCacheMethod
+        Inherits BaseMethod
+
+        Public Sub New(pLogConfig As LogConfig, pDatabaseIDB As MSSQLServer, pDatabaseECM As MSSQLServer, pGlobalState As GlobalState)
+            MyBase.New(pLogConfig, pDatabaseIDB, pDatabaseECM, pGlobalState)
+        End Sub
+
+        Public Function Run(pData As GetDatatableFromCacheRequest) As GetDatatableFromCacheResponse
+            Try
+                Logger.Debug($"ReturnDatatableFromCache: Datatable: {pData.DataTable}")
+
+                Dim oDataTable As DataTable = Nothing
+
+                Logger.Debug("ReturnDatatableFromCache: DataSet contains [{0}] datatables", GlobalState.TableStore.Tables.Count)
+
+                If GlobalState.TableStore.Tables.Contains(pData.DataTable) Then
+                    oDataTable = GlobalState.TableStore.Tables.Item(pData.DataTable).Copy()
+
+                    ' Apply filter and sorting to data
+                    Dim oFilterExpression As String = Utils.NotNull(pData.FilterExpression, String.Empty)
+                    Dim oSortByColumn As String = Utils.NotNull(pData.SortByColumn, String.Empty)
+
+                    Dim oFilteredRows = oDataTable.Select(oFilterExpression, oSortByColumn)
+                    Dim oFilteredTable As DataTable = Nothing
+
+                    If oFilteredRows.Count > 0 Then
+                        oFilteredTable = oFilteredRows.CopyToDataTable()
+                        oFilteredTable.TableName = pData.DataTable
+                    Else
+                        ' Produce empty table
+                        oFilteredTable = oDataTable.Clone()
+                        oFilteredTable.TableName = pData.DataTable
+                    End If
+
+                    Logger.Debug("ReturnDatatableFromCache: Datatable Stats for [{0}]:", pData.DataTable)
+                    Logger.Debug("Unfiltered: [{0}] rows", oDataTable.Rows.Count)
+                    Logger.Debug("Filtered: [{0}] rows", oFilteredTable.Rows.Count)
+
+                    Return New GetDatatableFromCacheResponse(oFilteredTable)
+                Else
+                    Logger.Warn($"ReturnDatatableFromCache: Datatable {pData.DataTable} does not exist")
+
+                    Return New GetDatatableFromCacheResponse(New KeyNotFoundException($"Datatable {pData.DataTable} does not exist"))
+                End If
+
+            Catch ex As Exception
+                Logger.Error(ex)
+                Return New GetDatatableFromCacheResponse(ex)
+
+            End Try
+        End Function
+    End Class
+
+End Namespace