private static SelectStatement CreateSelectFromLevelQuery(IEntity rootEntity, DbRelation recursiveRelation, SearchCondition leafFilter, int level, LevelQuerySelectList itemsToSelect)
{
if (level > Settings.GenericHierarchicalQueryExecutorMaxLevel)
throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, Messages.GenericHierarchicalQueryExecutor_MaxLevelReachedFormat, Settings.GenericHierarchicalQueryExecutorMaxLevel));
// Target level table must be child table because that is the table which is used in leafFilter.
// If leaf filter is used then the we must ensure that proper table name is used for target table.
IDbTable targetLevelTable;
if (leafFilter != null && !leafFilter.IsEmpty)
targetLevelTable = recursiveRelation.Child;
else
targetLevelTable = rootEntity.Table.Clone("L" + level);
SelectStatement selectFromTargetLevel = new SelectStatement(targetLevelTable);
CreateSelectListItems(itemsToSelect, targetLevelTable, selectFromTargetLevel);
if (leafFilter != null && !leafFilter.IsEmpty)
selectFromTargetLevel.Where.Add(leafFilter);
IDbTable prevLevel = targetLevelTable;
for (int parentLevel = level - 1; parentLevel >= 0; parentLevel--)
{
IDbTable nextLevel = rootEntity.Table.Clone("L" + parentLevel);
DbRelation joinLevels = JoinLevelsInSubTree(prevLevel, nextLevel, recursiveRelation);
selectFromTargetLevel.Relations.Add(joinLevels, false, false);
prevLevel = nextLevel;
}
IDbTable subTreeRoot = prevLevel;
foreach (IDbColumn rootPkPart in subTreeRoot.PrimaryKey)
selectFromTargetLevel.Where.Add(rootPkPart, rootEntity.GetField(rootPkPart));
return selectFromTargetLevel;
}
private static void CreateSelectListItems(LevelQuerySelectList itemsToSelect, IDbTable targetLevelTable, SelectStatement selectFromTargetLevel)
{
if (itemsToSelect == LevelQuerySelectList.AllColumns)
selectFromTargetLevel.SelectList.Add(targetLevelTable.Columns);
else if (itemsToSelect == LevelQuerySelectList.Count)
selectFromTargetLevel.SelectList.Add(AggregateFunctionFactory.Count("nodeCount"));
else if (itemsToSelect == LevelQuerySelectList.PrimaryKey)
selectFromTargetLevel.SelectList.Add(targetLevelTable.PrimaryKey);
}
