Forum Discussion
Helper IITable.View - Handling NestedJoin + Expand
This maps to:
- Table RenameColumns (if join columns have the same name)
- Table.Join
- Table.SelectColumns (if join columns have the same name)
Note: A nested join using left outer will not result in any calls to the connector. It simply adds a virtual table column waiting to be expanded. Other join types will break folding, performing an expand column afterwards will unbreak folding.
Microsoft EmployeeHere is a list of handlers:
OnAddColumns = (constructors as {[Name = text, Function = (row as record) => any, Type = type]}) as table => ...
OnCombine = (tables as {table}, index as Int64.Type) as table => ...,
OnDistinct = (columns as {text}) as table => ...,
OnGroup = (keys as {text}, aggregates as {[Name = text, Function = (subtable as table) => any, Type = type]}) => ...,
OnInvoke = (function as function, arguments as list, index as Int64.Type) as any => ...,
OnJoin = (joinSide as Int64.Type, leftTable as table, rightTable as table, joinKeys as {text}, joinKind as JoinKind.Type) as table => ...,
OnPivot = (pivotValues as list, attributeColumn as {text}, valueColumn as text, aggregateFunction as (items as list) as any) as table => ...,
OnRenameColumns = (renames as {text}) as table => ...,
OnSelectColumns = (columns as {text}) => ...,
OnSelectRows = (condition as (row as record) as logical) as table => ...,
OnSkip = (count as Int64.Type) as table => ...,
OnSort = (order as {[Name = as text, Order as Order.Type]}) as table => ...,
OnTake = (count as Int64.Type) as table => ...,
OnUnpivot = (pivotColumns as {text}, attributeColumn as text, valueColumn as text) as table => ...,
OnNativeQuery = (query as text, optional parameters as any, optional options as any) as any => ...,
Some operations are not foldable, others still are expressed in terms of other operations like Table.NestedInnerJoin.
Helper IIHi artemus,
Thank you for this list of handlers.
Could you tell me which handler (or sequence of handlers) a Table.NestedJoin call followed by a Table.ExpandTableColumn maps to?
Thank you!
- artemus
This maps to:
- Table RenameColumns (if join columns have the same name)
- Table.Join
- Table.SelectColumns (if join columns have the same name)
Note: A nested join using left outer will not result in any calls to the connector. It simply adds a virtual table column waiting to be expanded. Other join types will break folding, performing an expand column afterwards will unbreak folding.