Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
///*
let func =
(ParChTable as table,
ChildKey as text,
ParentKey as text,
LevelColumnName as text) =>
//*/
let
/*/Debug Parameters
ParChTable = SourceData_Loop,
ChildKey = "NodeKey",
ParentKey = "ParentKey",
LevelColumnName = "Name",
*/
SelectRelevantColumns = Table.SelectColumns(ParChTable, {ChildKey, ParentKey, LevelColumnName}),
#"Changed Type" = Table.TransformColumnTypes(SelectRelevantColumns ,{{ChildKey, type text}, {ParentKey, type text}}),
ReplaceNulls = Table.ReplaceValue(#"Changed Type",null,"",Replacer.ReplaceValue,{ParentKey}),
// CleanParChTable = Table.Distinct(ReplaceNulls , {ChildKey, ParentKey}),
MissingParents = List.Buffer(List.Select(List.Difference(List.Distinct(Table.Column(ReplaceNulls , ParentKey)), List.Distinct(Table.Column(ReplaceNulls , ChildKey))), each _ <> "")),
AddMissingParents = Table.Buffer(Table.Combine({ReplaceNulls , #table({ChildKey, LevelColumnName, ParentKey}, List.Transform(MissingParents, each {_, "Unknown TopLevel"& Text.From(List.PositionOf(MissingParents, _)), ""}))})),
#"Merged Queries0" = Table.NestedJoin(AddMissingParents,{ChildKey},AddMissingParents,{ParentKey},"SelectRelevantColumns",JoinKind.LeftOuter),
CheckIfIsLeaf = Table.AddColumn(#"Merged Queries0", "IsLeaf", each if Table.IsEmpty([SelectRelevantColumns]) then "yes" else "no"),
#"Replaced Value1" = Table.ReplaceValue(CheckIfIsLeaf,null,"",Replacer.ReplaceValue,{ParentKey, LevelColumnName}),
AddStartPath = Table.AddColumn(#"Replaced Value1", "Path", each Text.Trim(Record.Field(_, ChildKey)&"|"&Record.Field(_,ParentKey), "|")),
#"Duplicated Column" = Table.DuplicateColumn(AddStartPath, LevelColumnName, "FirstName"),
Feed = Table.DuplicateColumn(#"Duplicated Column", ParentKey, "FirstParentKey"),
// Retrieve all parents per row
fnAllParents = List.Generate(()=>
[Result= Feed, Level=1, EndlessLoop = false, StopEndlessLoop = false],
each Table.RowCount([Result]) > 0 and not [StopEndlessLoop],
each [ Result= let
#"Merged Queries" = Table.NestedJoin([Result],{ParentKey},AddMissingParents,{ChildKey},"Added Custom",JoinKind.Inner),
#"Removed Columns1" = Table.RemoveColumns(#"Merged Queries",{ParentKey}),
#"Expanded Added Custom" = Table.ExpandTableColumn(#"Removed Columns1", "Added Custom", {ParentKey, LevelColumnName}, {"ParentKey.1", "Name.1"}),
#"Duplicated Column" = Table.DuplicateColumn(#"Expanded Added Custom", "ParentKey.1", ParentKey),
#"Merged Columns" = Table.CombineColumns(#"Duplicated Column",{"Path", "ParentKey.1"},Combiner.CombineTextByDelimiter("|", QuoteStyle.None),"Path"),
#"Merged Columns2" = Table.CombineColumns( #"Merged Columns" ,{LevelColumnName, "Name.1"},Combiner.CombineTextByDelimiter("|", QuoteStyle.None),LevelColumnName)
in
Table.Buffer(#"Merged Columns2"),
Level = [Level]+1,
EndlessLoop = List.Sort(List.Distinct(Table.Column(Result, ChildKey))) = List.Sort(List.Distinct(Table.Column([Result], ChildKey))),
StopEndlessLoop = [EndlessLoop]
]),
ConvertToTable = Table.FromList(fnAllParents, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
ExpandLevel = Table.ExpandRecordColumn(ConvertToTable, "Column1", {"Result", "Level", "EndlessLoop"}, {"Result", "Level", "EndlessLoop"}),
ExpandLG = Table.ExpandTableColumn(ExpandLevel, "Result", {LevelColumnName, ParentKey, ChildKey, "Path", "FirstName", "FirstParentKey"}, {"Name", "ParentKey", "NodeKey", "Path", "FirstName", "FirstParentKey"}),
FilterParents = Table.SelectRows(ExpandLG, each ([ParentKey] = null or [ParentKey] = "")),
#"Removed Columns" = Table.RemoveColumns(FilterParents,{"ParentKey"}),
#"Trimmed Text" = Table.TransformColumns(#"Removed Columns",{{"Path", each Text.Trim(_, "|")}}),
ReverseOrderName = Table.TransformColumns(#"Trimmed Text",{{"Name", each Text.Combine(List.Reverse(Text.Split(_, "|")), "|")}}),
ReverseOrderPath = Table.TransformColumns(ReverseOrderName,{{"Path", each Text.Combine(List.Reverse(Text.Split(_, "|")), "|")}}),
#"Reordered Columns" = Table.ReorderColumns(ReverseOrderPath,{"NodeKey", "FirstParentKey", "Path", "FirstName", "Level", "Name"}),
#"Split Column by Delimiter" = Table.SplitColumn(#"Reordered Columns", "Name", Splitter.SplitTextByDelimiter("|", QuoteStyle.Csv), List.Transform({1..Table.RowCount(ConvertToTable)}, each "Level "&Text.From(_))),
#"Merged Queries" = Table.NestedJoin(#"Split Column by Delimiter",{"NodeKey", "FirstParentKey"},ParChTable ,{ChildKey, ParentKey},"Split Column by Delimiter",JoinKind.LeftOuter),
#"Expanded Split Column by Delimiter" = Table.ExpandTableColumn(#"Merged Queries", "Split Column by Delimiter", List.Difference(Table.ColumnNames(ParChTable), Table.ColumnNames(#"Replaced Value1"))),
Rename = Table.RenameColumns(#"Expanded Split Column by Delimiter",{{"Level", "HierarchyDepth"}}),
Parents = List.Buffer(Rename[FirstParentKey]),
IsLeaf = Table.AddColumn(Rename, "IsLeaf", each not List.Contains(Parents, [NodeKey])),
NoOfInterations = List.Count(fnAllParents),
LastIteration = Table.SelectRows(ExpandLG, each ([Level] = NoOfInterations)),
EndlessLoops = LastIteration[EndlessLoop],
IsEndlessLoop = EndlessLoops{0},
RemainingResults = Table.NestedJoin(IsLeaf, {ChildKey}, LastIteration, {ChildKey}, "x", JoinKind.LeftAnti),
Custom1 = if IsEndlessLoop then [Message= "The data is in an endless loop. Check Table in ""Endless Loop""", #" Endless Loop"= LastIteration] meta [ResultsSoFar = RemainingResults] else IsLeaf
in
Custom1
///*
, documentation = [
Documentation.Name = " Table.SolveParentChild
", Documentation.Description = " Creates columns for all parents, multiple parents are supported
" , Documentation.LongDescription = " Creates columns for all parents, multiple parents are supported
", Documentation.Category = " Table
", Documentation.Version = " 2.0: Checking for endless loops
", Documentation.Source = " local
", Documentation.Author = " Imke Feldmann: www.TheBIccountant.com
", Documentation.Examples = {[Description = " See: http://wp.me/p6lgsG-sl for more details
" , Code = "
", Result = "
"]}]
in
Value.ReplaceType(func, Value.ReplaceMetadata(Value.Type(func), documentation))
//*/
@ImkeF

This comment has been minimized.

Copy link
Owner Author

@ImkeF ImkeF commented Nov 14, 2020

Added control to stop during endless loop

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.