using Sarand.Net.Standard.Dbas.Data;
using Sarand.Net.Standard.Base.App;
using Sarand.Net.Standard.Base.Bus;
using Sarand.Net.Standard.Base.Core;
using Sarand.Net.Standard.Base.Dbas;
using Saxonite.Base.App;
using Saxonite.Net.Standard.Dbas.Bus;
using Saxonite.Net.Standard.Dbas.Internal;
using Saxonite.Net.Standard.Base.App;
using Saxonite.Net.Standard.Base.Bus;
using System;
using System.Collections.Generic;
using System.Data.Common;
using System.Text;
using Sarand.Net.Standard.Base.Utils;
using System.Linq;
using Saxonite.Net.Standard.Dbas.Internal.Core;

namespace Saxonite.Net.Standard.Dbas.Mgr
{
	//=======================================================================
	partial class SaxReferenceMgr_Dbas
	{
		//*******************************************************************
		// Reference Mgr - Region
		//*******************************************************************
		// Utilities.
		private List<StringPair> GetLogProperties(SaxRegion region)
		{
			return new List<StringPair>()
			{
				new StringPair("Id", SysId.ToString(region.Id)),
				new StringPair("ISO2", region.CountryIso2Code),
				new StringPair("Name", region.Name),
				new StringPair("Status", region.StatusCode)
			};
		}

		//-------------------------------------------------------------------
		// Create item.
		public override SaxRegion CreateRegion()
		{
			ClearErrorState();
			return new SaxRegion_Dbas(CoreDatabase, null, 0);
		}
		private SaxRegion_Dbas CreateRegion(Region_Db dbRegion)
		{
			ClearErrorState();
			SaxRegion_Dbas region = new SaxRegion_Dbas(CoreDatabase, new SysId(dbRegion._Id), (UInt16)dbRegion._Flags);
			PopulateFrom(dbRegion, region);
			return region;
		}

		//-------------------------------------------------------------------
		// Get item.
		public override SaxRegion GetRegion(SaxRegion.Params prm)
		{
			ClearErrorState();
			return GetRegion(GetRegionQueryFilter(prm).Concat(" And ", "(", ")"));
		}
		private SaxRegion GetRegion(String filter)
		{
			ClearErrorState();
			long count = GetRegionCount(filter);
			if (count == 0) return null;
			if (count != 1)
			{
				SetErrorState("Multiple items found");
				return null;
			}
			SaxRegion region = null;
			// Query data.
			using (var dbConnection = CoreDatabase.CreateConnection())
			using (var dbCommand = dbConnection.CreateCommand())
			{
				try
				{
					dbConnection.Open();
					Region_Db dbRegion = new Region_Db(CoreDbInfo);
					dbRegion.PopulateFrom(dbCommand, aliasRegion, filter);
					region = CreateRegion(dbRegion);
				}
				catch (Exception exc)
				{
					SetErrorState("Database query exception");
					SaLogger.Warn($"{SysUtil.Fn}\n\tQuery: {dbCommand.CommandText}\n\t{ExceptionUtil.GetErrorStateMessage(exc)}");
				}
			}
			return region;
		}

		//-------------------------------------------------------------------
		// Validate item.
		public override bool IsValidRegionData(SaxRegion.Data data, SaxRegion.ErrField errField)
		{
			ClearErrorState();
			if (!base.IsValidRegionData(data, errField)) return false;
			return true;
		}

		//-------------------------------------------------------------------
		// Insert item.
		public override bool InsertRegion(SaxRegion region, DbUpdateInfo dbUpdateInfo)
		{
			ClearErrorState();
			if (!IsValidRegion(region)) return false;
			if (SysId.IsValid(region.Id)) return SetErrorState(ErrorMessage.ValidItemId);
			using (var dbConnection = CoreDatabase.CreateConnection())
			using (var dbCommand = dbConnection.CreateCommand())
			{
				try
				{
					dbConnection.Open();
					Region_Db dbRegion = new Region_Db(CoreDbInfo);
					PopulateTo(dbRegion, region, dbUpdateInfo);
					if (Region_Db.FieldsNonId.Contains("Id"))
					{
						// Generate next Id.
						// ToDo dbRegion._Id = CoreDatabase.GetNextIdFromTable("Region");
					}
					dbRegion.ExecuteInsertCommand(dbCommand);
					region.Id = new SysId(dbRegion._Id);
					region.Changed = false;
					if (DebugMode) SaLogger.Debug($"{SysUtil.Fn} Inserted.{GetLogProperties(region).Concat(": ").Concat("", "\n\t")}");
				}
				catch (Exception exc) { SetErrorState(exc.Message); }
			}
			return !HasErrorState();
		}

		//-------------------------------------------------------------------
		// Update item.
		public override bool UpdateRegion(SaxRegion region, DbUpdateInfo dbUpdateInfo)
		{
			ClearErrorState();
			if (!IsValidRegion(region)) return false;
			if (!SysId.IsValid(region.Id)) return SetErrorState(ErrorMessage.InvalidItemId);
			if (!region.Changed)
			{
				if (DebugMode) SaLogger.Debug($"{SysUtil.Fn} Data not changed.{GetLogProperties(region).Concat(": ").Concat("", "\n\t")}");
				return true;
			}
			using (var dbConnection = CoreDatabase.CreateConnection())
			using (var dbCommand = dbConnection.CreateCommand())
			{
				try
				{
					// Retrieve item.
					dbConnection.Open();
					Region_Db dbRegion = new Region_Db(CoreDbInfo);
					dbRegion.PopulateFrom(dbCommand, aliasRegion, "Id=" + SysId.ToString(region.Id));
					// ToDo SaxUpdateLogItemMonitor_Region updateLogMonitor = new SaxUpdateLogItemMonitor_Region(SessionContext, CreateRegion(dbRegion), dbUpdateInfo);
					// Update item.
					PopulateTo(dbRegion, region, dbUpdateInfo);
					dbRegion.ExecuteUpdateCommand(dbCommand);
					region.Changed = false;
					if (DebugMode) SaLogger.Debug($"{SysUtil.Fn} Updated.{GetLogProperties(region).Concat(": ").Concat("", "\n\t")}");
					// Record updates.
					// ToDo updateLogMonitor.RecordUpdatedValues(region);
					// ToDo updateLogMonitor.LogUpdates();
				}
				catch (Exception exc) { SetErrorState(exc.Message); }
			}
			return !HasErrorState();
		}

		//-------------------------------------------------------------------
		// Delete item.
		public override bool RegionCanBeDeleted(SaxRegion region)
		{
			ClearErrorState();
			if (!base.RegionCanBeDeleted(region)) return false;
			return true;
		}
		public override bool DeleteRegion(SaxRegion region, DbUpdateInfo dbUpdateInfo)
		{
			ClearErrorState();
			if (!RegionCanBeDeleted(region)) return false;

			// Regions are logically deleted by changing the status.
			region.Status = SaStatus.Deleted;
			return UpdateRegion(region, dbUpdateInfo);

			/*
			 * Physical deletion.
			using (var dbConnection = CoreDatabase.CreateConnection())
			using (var dbCommand = dbConnection.CreateCommand())
			{
				try
				{
					// Retrieve item.
					dbConnection.Open();
					Region_Db dbRegion = new Region_Db(CoreDbInfo);
					dbRegion.PopulateFrom(dbCommand, aliasRegion, "Id=" + region.Id.ToString());
					// Delete item.
					dbCommand.CommandType = System.Data.CommandType.Text;
					dbCommand.CommandText = "DELETE FROM " + SaxDbDfn_Core.GetTableName(SaxDbDfn_Core.TableIdx.Region) + " WHERE Id=" + SysId.ToString(region.Id) + ";";
					dbCommand.ExecuteNonQuery();
					region.Changed = false;
					if (DebugMode) SaLogger.Debug($"{SysUtil.Fn} Deleted. " + GetLogProperties(region).Concat(": ").Concat("", "\n\t"));
				}
				catch (Exception exc) { SetErrorState(exc.Message); }
			}
			return !HasErrorState();
			*/
		}

		//-------------------------------------------------------------------
		// Copy data properties to and from database.
		private void PopulateTo(Region_Db dbRegion, SaxRegion region, DbUpdateInfo dbUpdateInfo)
		{
			dbRegion._Id = SysId.ToInt(region.Id);
			dbRegion._RegionType = (short)region.RegionType;
			dbRegion._CountryIso2Code = region.CountryIso2Code;
			dbRegion._Name = region.Name;
			dbRegion._Latitude = region.Latitude;
			dbRegion._Longitude = region.Longitude;
			dbRegion._RegionIdParent = SysId.ToInt(region.RegionIdParent);
			dbRegion._Notes = region.Notes;
			dbRegion._Status = SacsSystem.GetStatusCode(region.Status);
			dbRegion._Flags = (short)region.Flags;
			if (!SysId.IsValid(region.Id))
			{
				dbRegion._CreateOn = DateTime.Now;
				dbRegion._CreateBy = dbUpdateInfo.UserId.ToInt();
				dbRegion._CreateHost = dbUpdateInfo.Host;
			}
			dbRegion._UpdateOn = DateTime.Now;
			dbRegion._UpdateBy = dbUpdateInfo.UserId.ToInt();
			dbRegion._UpdateHost = dbUpdateInfo.Host;
		}
		private void PopulateFrom(Region_Db dbRegion, SaxRegion region)
		{
			//region.Id = new SysId(dbRegion._Id);
			region.RegionType = (Sax.RegionType)dbRegion._RegionType;
			region.CountryIso2Code = dbRegion._CountryIso2Code;
			region.Name = dbRegion._Name;
			region.Latitude = dbRegion._Latitude;
			region.Longitude = dbRegion._Longitude;
			region.RegionIdParent = new SysId(dbRegion._RegionIdParent);
			region.Notes = dbRegion._Notes;
			region.Status = SacsSystem.GetStatusForCode(dbRegion._Status);
			region.SetCreateStamp(dbRegion._CreateOn, new SysId(dbRegion._CreateBy), dbRegion._CreateHost);
			region.SetUpdateStamp(dbRegion._UpdateOn, new SysId(dbRegion._UpdateBy), dbRegion._UpdateHost);
			region.AcceptChanges();
		}

		//-------------------------------------------------------------------
		// Item column definitions.
		private static readonly String aliasRegion = "Rgn";
		private static readonly String aliasRegion_Parent = "PrtRgn";
		private static readonly String prefixRegion_Parent = "PrtRgn_";
		private static readonly String colRegion_ChildRegion_Count = "Rgn_ChildRegionCount";
		private void SetRegionColDfn
			(ColumnDfn col, String caption, int width, SaxDbDfn_Core.ColumnIdx dbCol,
			ColumnAlignment align = ColumnAlignment.Default, DataValue.DataType dataType = DataValue.DataType.String,
			String alias = "", String prefix = "")
		{
			if (String.IsNullOrEmpty(alias) && SaxDbDfn_Core.GetTableForColumn(dbCol) == SaxDbDfn_Core.TableIdx.Region)
				alias = aliasRegion;
			col.Set(caption, width, (int)dbCol, prefix + SaxDbDfn_Core.GetColumnName(dbCol, false), SaxDbDfn_Core.GetColumnNameQual(dbCol, alias), dataType, align);
			if (dataType == DataValue.DataType.String && dbCol != SaxDbDfn_Core.ColumnIdx.Unknown)
				col.MaxLength = (int)SaxDbDfn_Core.GetColTextLen(dbCol);
		}
		public override ColumnDfn GetRegionColumnDfn(SaxRegion.Column columnId, string caption = "", int width = 0)
		{
			ColumnDfn columnDfn = new ColumnDfn((int)columnId, caption, width);
			switch (columnId)
			{
				//-----------------------------------------------------------
				case SaxRegion.Column.Pos:
					SetRegionColDfn(columnDfn, "Pos", 60, SaxDbDfn_Core.ColumnIdx.Unknown, ColumnAlignment.Right);
					columnDfn.SortMode = ColumnDfn.ColumnSortMode.Off;
					columnDfn.ReadOnly = true;
					columnDfn.Resizable = false;
					break;
				case SaxRegion.Column.Id:
					SetRegionColDfn(columnDfn, "Id", 80, SaxDbDfn_Core.ColumnIdx.Region_Id, ColumnAlignment.Right, DataValue.DataType.Long);
					columnDfn.ReadOnly = true;
					break;
				case SaxRegion.Column.RegionType:
					SetRegionColDfn(columnDfn, "Type", 80, SaxDbDfn_Core.ColumnIdx.Region_RegionType, ColumnAlignment.Center, DataValue.DataType.Long);
					break;
				case SaxRegion.Column.RegionType_Desc:
					SetRegionColDfn(columnDfn, "Type", 100, SaxDbDfn_Core.ColumnIdx.Region_RegionType, ColumnAlignment.Center, DataValue.DataType.String);
					break;
				case SaxRegion.Column.CountryIso2Code:
					SetRegionColDfn(columnDfn, "ISO2", 60, SaxDbDfn_Core.ColumnIdx.Region_CountryIso2Code, ColumnAlignment.Center);
					break;
				case SaxRegion.Column.Name:
					SetRegionColDfn(columnDfn, "Name", 120, SaxDbDfn_Core.ColumnIdx.Region_Name);
					break;

				//-----------------------------------------------------------
				// Parent Region.
				case SaxRegion.Column.RegionIdParent:
					SetRegionColDfn(columnDfn, "Parent Id", 80, SaxDbDfn_Core.ColumnIdx.Region_RegionIdParent, ColumnAlignment.Right, DataValue.DataType.Long);
					break;
				case SaxRegion.Column.Parent_RegionType:
					SetRegionColDfn(columnDfn, "Parent type", 80, SaxDbDfn_Core.ColumnIdx.Region_RegionType, ColumnAlignment.Center, DataValue.DataType.Long, aliasRegion_Parent, prefixRegion_Parent);
					columnDfn.ReadOnly = true;
					break;
				case SaxRegion.Column.Parent_RegionType_Desc:
					SetRegionColDfn(columnDfn, "Parent type", 100, SaxDbDfn_Core.ColumnIdx.Region_RegionType, ColumnAlignment.Center, DataValue.DataType.String, aliasRegion_Parent, prefixRegion_Parent);
					columnDfn.ReadOnly = true;
					break;
				case SaxRegion.Column.Parent_Name:
					SetRegionColDfn(columnDfn, "Parent", 120, SaxDbDfn_Core.ColumnIdx.Region_Name, ColumnAlignment.Left, DataValue.DataType.String, aliasRegion_Parent, prefixRegion_Parent);
					columnDfn.ReadOnly = true;
					break;

				//-----------------------------------------------------------
				// Derived properties.
				case SaxRegion.Column.ChildRegionCount:
					SetRegionColDfn(columnDfn, "Sub regions", 90, SaxDbDfn_Core.ColumnIdx.Unknown, ColumnAlignment.Center, DataValue.DataType.Long);
					columnDfn.DataName = colRegion_ChildRegion_Count;
					columnDfn.ReadOnly = true;
					break;

				//-----------------------------------------------------------
				// Common properties.
				case SaxRegion.Column.Notes:
					SetRegionColDfn(columnDfn, "Notes", 240, SaxDbDfn_Core.ColumnIdx.Region_Notes);
					break;
				case SaxRegion.Column.Flags:
					SetRegionColDfn(columnDfn, "Flags", 60, SaxDbDfn_Core.ColumnIdx.Region_Flags, ColumnAlignment.Center, DataValue.DataType.Long);
					break;
				case SaxRegion.Column.Status:
					SetRegionColDfn(columnDfn, "Status", 80, SaxDbDfn_Core.ColumnIdx.Region_Status, ColumnAlignment.Center);
					break;
				case SaxRegion.Column.Status_Desc:
					SetRegionColDfn(columnDfn, "Status", 90, SaxDbDfn_Core.ColumnIdx.Region_Status, ColumnAlignment.Center);
					break;
				case SaxRegion.Column.Status_Ind:
					SetRegionColDfn(columnDfn, "Status", 80, SaxDbDfn_Core.ColumnIdx.Region_Status, ColumnAlignment.Center, DataValue.DataType.TriState);
					columnDfn.TriStateFormat = ColumnTriStateFormat.Lights;
					break;
				case SaxRegion.Column.CreateOn_Date:
					SetRegionColDfn(columnDfn, "Created", 80, SaxDbDfn_Core.ColumnIdx.Region_CreateOn, ColumnAlignment.Center, DataValue.DataType.Date);
					columnDfn.ReadOnly = true;
					break;
				case SaxRegion.Column.UpdateOn_Date:
					SetRegionColDfn(columnDfn, "Updated", 80, SaxDbDfn_Core.ColumnIdx.Region_UpdateOn, ColumnAlignment.Center, DataValue.DataType.Date);
					columnDfn.ReadOnly = true;
					break;
					//-----------------------------------------------------------
			}
			if (!String.IsNullOrEmpty(caption))
				columnDfn.Caption = caption;
			if (width > 0)
				columnDfn.Width = width;
			return columnDfn;
		}

		//-------------------------------------------------------------------
		// Item query filter.
		public override List<string> GetRegionQueryFilter(SaxRegion.Params prm)
		{
			List<String> filter = new List<String>();

			// Item Ids.
			String idsIncluded = prm.IdsIncluded.Concat(",");
			if (!idsIncluded.IsEmpty())
				filter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Id, aliasRegion) + " IN (" + idsIncluded + ")");
			String idsExcluded = prm.IdsExcluded.Concat(",");
			if (!idsExcluded.IsEmpty())
				filter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Id, aliasRegion) + " NOT IN (" + idsExcluded + ")");

			// Parent Region Ids.
			String includedParentRegionIds = prm.ParentRegionIdsIncluded.Concat(",");
			if (!includedParentRegionIds.IsEmpty())
				filter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_RegionIdParent, aliasRegion) + " IN (" + includedParentRegionIds + ")");

			// Region type.
			if ((int)prm.RegionType > 0)
				filter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_RegionType, aliasRegion) + "=" + (int)prm.RegionType);

			// ISO 2 codes.
			if (!prm.CountryIso2CodesIncluded.IsEmpty())
				filter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_CountryIso2Code, aliasRegion) + " IN (" + DbQuery.FormatForIn(prm.CountryIso2CodesIncluded, true, false) + ")");
			if (!prm.CountryIso2CodesExcluded.IsEmpty())
				filter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_CountryIso2Code, aliasRegion) + " NOT IN (" + DbQuery.FormatForIn(prm.CountryIso2CodesExcluded, true, false) + ")");

			// Generic filter.
			if (!StringUtil.IsEmpty(prm.RegionFilter))
			{
				// Split filter into words.
				List<String> filterWords = prm.RegionFilter.Split((char[])null).ToList();
				filterWords.RemoveDuplicatesCI();
				filterWords.RemoveBlanks();
				foreach (String filterWord in filterWords)
				{
					List<String> regionFilter = new List<String>();
					regionFilter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_CountryIso2Code, aliasRegion) + " Like '%" + DbQuery.FormatForLike(filterWord, true) + "%'");
					regionFilter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Name, aliasRegion) + " Like '%" + DbQuery.FormatForLike(filterWord, true) + "%'");
					filter.Add(regionFilter.Concat(" OR ", "(", ")"));
				}
			}

			// Name.
			if (!StringUtil.IsEmpty(prm.NameFull))
				filter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Name, aliasRegion) + "='" + DbQuery.FormatForCondition(prm.NameFull) + "'");
			if (!StringUtil.IsEmpty(prm.NamePartial))
				filter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Name, aliasRegion) + " Like '%" + DbQuery.FormatForLike(prm.NamePartial, true) + "%'");

			// Notes.
			if (!StringUtil.IsEmpty(prm.NotesPartial))
				filter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Notes, aliasRegion) + " LIKE '%" + DbQuery.FormatForLike(prm.NotesPartial) + "%'");

			// Status.
			if (prm.StatusCat != SaxRegion.StatusCat.Any)
				filter.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Status, aliasRegion) + GetRegionStatusCatFilterCondition(prm.StatusCat));

			if (filter.Count < 1) filter.Add("1=1");
			return filter;
		}
		internal static String GetRegionStatusCatFilterCondition(SaxRegion.StatusCat statusCat)
		{
			if (statusCat == SaxRegion.StatusCat.ActiveOnly)
				return "='" + SacsSystem.GetStatusCode(SaStatus.Active) + "'";
			if (statusCat == SaxRegion.StatusCat.InactiveOnly)
				return "='" + SacsSystem.GetStatusCode(SaStatus.Inactive) + "'";
			if (statusCat == SaxRegion.StatusCat.NotDeleted)
				return "!='" + SacsSystem.GetStatusCode(SaStatus.Deleted) + "'";
			if (statusCat == SaxRegion.StatusCat.DeletedOnly)
				return "='" + SacsSystem.GetStatusCode(SaStatus.Deleted) + "'";
			return "";
		}
		// Item sort columns.
		public List<String> GetRegionSortColumns(SaxRegion.Params prm)
		{
			// Sort sequence:
			List<String> sortColumnNames = new List<String>();
			foreach (var columnDfn in prm.SortColumns)
			{
				// Need to ensure correct alias used for Region columns in case of conflict.
				String sortCol = String.Empty;
				if (SaxDbDfn_Core.GetTableForColumn((SaxDbDfn_Core.ColumnIdx)columnDfn.DbColumn) == SaxDbDfn_Core.TableIdx.Region)
				{
					sortCol = SaxDbDfn_Core.GetColumnNameQual((SaxDbDfn_Core.ColumnIdx)columnDfn.DbColumn, aliasRegion);
				}
				else
				{
					sortCol = columnDfn.DataName;
					if (!StringUtil.IsEmpty(columnDfn.SortDataName))
						sortCol = columnDfn.SortDataName;
				}
				if (!sortCol.IsEmpty())
				{
					DbOrderByNullMode orderByNullMode = DbOrderByNullMode.Default; // eSaOrderByDemoteNulls, eSaOrderByPromoteNulls
					sortColumnNames.Add(DbQuery.FormatForOrderBy(sortCol, columnDfn.SortAscending, orderByNullMode).Concat(", "));
				}
			}
			sortColumnNames.RemoveBlanks();
			if (sortColumnNames.IsEmpty())
			{
				// Default sort columns.
				sortColumnNames.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Id, aliasRegion) + " ASC");
			}
			return sortColumnNames;
		}

		//-------------------------------------------------------------------
		// Item count.
		private long GetRegionCount(String filter)
		{
			ClearErrorState();
			return CoreDatabase.GetRowCount(SaxDbDfn_Core.GetTableName(SaxDbDfn_Core.TableIdx.Region) + " As " + aliasRegion, filter);
		}
		public override long GetRegionCount(SaxRegion.Params prm)
		{
			ClearErrorState();
			return GetRegionCount(GetRegionQueryFilter(prm).Concat(" AND ", "(", ")"));
		}

		//-------------------------------------------------------------------
		// Item list.
		public override List<SaxRegion> GetRegionList(SaxRegion.Params prm)
		{
			ClearErrorState();
			List<SaxRegion> userReferences = new List<SaxRegion>();
			DbQuery qry = new DbQuery(CoreDatabase.DbmsType);
			qry.Tables.Add(SaxDbDfn_Core.GetTableName(SaxDbDfn_Core.TableIdx.Region), aliasRegion);
			Region_Db dbRegion = new Region_Db(CoreDbInfo);
			qry.Columns.AddRange(dbRegion.ExistingColumnNames);
			qry.Filters.AddRange(GetRegionQueryFilter(prm));
			qry.OrderBy.AddRange(GetRegionSortColumns(prm));
			// Query data.
			using (var dbConnection = CoreDatabase.CreateConnection())
			using (var dbCommand = dbConnection.CreateCommand())
			{
				try
				{
					dbConnection.Open();
					dbCommand.CommandText = qry.BuildQuery(prm.ResultsPaging);
					using (DbDataReader dbDataReader = dbCommand.ExecuteReader())
					{
						while (dbDataReader.Read())
						{
							dbRegion = new Region_Db(CoreDbInfo);
							dbRegion.PopulateFrom(dbDataReader);
							userReferences.Add(CreateRegion(dbRegion));
						}
					}
				}
				catch (Exception exc)
				{
					SetErrorState("Database query exception");
					SaLogger.Warn($"{SysUtil.Fn}\n\tQuery: {dbCommand.CommandText}\n\t{ExceptionUtil.GetErrorStateMessage(exc)}");
				}
			}
			return userReferences;
		}

		//-------------------------------------------------------------------
		// Item query execution.
		public override DbResultSet ExecuteRegionQuery(List<ColumnDfn> columns, SaxRegion.Params prm)
		{
			ClearErrorState();

			//---------------------------------------------------------------------
			// Construct query.
			DbQuery query = new DbQuery(CoreDatabase.DbmsType);
			query.Tables.Add(SaxDbDfn_Core.GetTableName(SaxDbDfn_Core.TableIdx.Region), aliasRegion);

			// Add columns as defined in query list.
			if (columns.HasId(SaxRegion.Column.Id))
				query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Id, aliasRegion));
			if (columns.HasId(SaxRegion.Column.RegionType) || columns.HasId(SaxRegion.Column.RegionType_Desc))
				query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_RegionType, aliasRegion));
			if (columns.HasId(SaxRegion.Column.CountryIso2Code))
				query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_CountryIso2Code, aliasRegion));
			if (columns.HasId(SaxRegion.Column.Name))
				query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Name, aliasRegion));
			bool hasParentRegionCols = columns.HasId(SaxRegion.Column.Parent_RegionType) || columns.HasId(SaxRegion.Column.Parent_RegionType_Desc) || columns.HasId(SaxRegion.Column.Parent_Name);
			if (columns.HasId(SaxRegion.Column.RegionIdParent) || hasParentRegionCols)
				query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_RegionIdParent, aliasRegion));
			// Common properties.
			if (columns.HasId(SaxRegion.Column.Notes))
				query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Notes, aliasRegion));
			if (columns.HasId(SaxRegion.Column.Flags))
				query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Flags, aliasRegion));
			if (columns.HasId(SaxRegion.Column.Status) || columns.HasId(SaxRegion.Column.Status_Desc) || columns.HasId(SaxRegion.Column.Status_Ind))
				query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Status, aliasRegion));
			if (columns.HasId(SaxRegion.Column.CreateOn_Date))
				query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_CreateOn, aliasRegion));
			if (columns.HasId(SaxRegion.Column.UpdateOn_Date))
				query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_UpdateOn, aliasRegion));

			//---------------------------------------------------------------------
			// Parent Region.
			if (hasParentRegionCols)
			{
				DbQueryJoin joinParentRegion = new DbQueryJoin(DbJoinType.LeftOuter);
				joinParentRegion.Table = new StringPair(SaxDbDfn_Core.GetTableName(SaxDbDfn_Core.TableIdx.Region), aliasRegion_Parent);
				joinParentRegion.Filters.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Id, aliasRegion_Parent) + "=" + SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_RegionIdParent, aliasRegion));
				query.Joins.Add(joinParentRegion);
				List<SaxDbDfn_Core.ColumnIdx> cols = new List<SaxDbDfn_Core.ColumnIdx>();
				cols.Add(SaxDbDfn_Core.ColumnIdx.Region_RegionType);
				cols.Add(SaxDbDfn_Core.ColumnIdx.Region_Name);
				foreach (var col in cols)
					query.Columns.Add(SaxDbDfn_Core.GetColumnNameQual(col, aliasRegion_Parent), prefixRegion_Parent + SaxDbDfn_Core.GetColumnName(col, false));
			}

			//---------------------------------------------------------------------
			// Child Region count.
			if (columns.HasId(SaxRegion.Column.ChildRegionCount))
			{
				String aliasCount = "aChildRgn";
				DbQuery queryCount = new DbQuery(CoreDatabase.DbmsType);
				queryCount.Tables.Add(SaxDbDfn_Core.GetTableName(SaxDbDfn_Core.TableIdx.Region), aliasCount);
				queryCount.Columns.Add("Count(*)");
				queryCount.Filters.Add(SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_RegionIdParent, aliasCount) + "=" + SaxDbDfn_Core.GetColumnNameQual(SaxDbDfn_Core.ColumnIdx.Region_Id, aliasRegion));
				query.Columns.Add("(" + queryCount.BuildQuery() + ")", colRegion_ChildRegion_Count);
			}

			//---------------------------------------------------------------------
			// Populate filter.
			query.Filters.AddRange(GetRegionQueryFilter(prm));

			if (prm.IdsIncluded.Count != 1)
			{
				// Configure sort sequence.
				foreach (String sortColumn in GetRegionSortColumns(prm))
					query.OrderBy.Add(sortColumn);
			}

			//---------------------------------------------------------------------
			//return new DbResultSet_DataTableReader(db, query.BuildQuery(prm.ResultsPaging));
			return DbResultSet_DataReader.ExecuteQuery(CoreDatabase, query.BuildQuery(prm.ResultsPaging));
		}

		//-------------------------------------------------------------------
	}
	//=======================================================================
}