Power Query (M) Select * from A where A.id = B.ID and B.date is last

[DenisBergeron]

Hello everybody.

I'm quite new ot PowerBI.

I try and fail doing this in power Query on Power BI.

I try and fail to find a exemple of this.

I have a BD Snapshot (that have all the snapshot from lot BDs and Tables).

In the Snapshot reference table I have "date_of_snapshot" and "SnapshotID".

And all the tables have a column "SnapshotID"

What I want to do, is simple, take the "SnapshotID" related to the  most recent "date_of_snapshot" and get all other query of to load only the data related to this last "SnapshotID".

Thanks stranger for your help

[DenisBergeron]

In MS-SSMS I can do this :

SELECT TOP (1) *  FROM [DataWarehouse].[dbo].[Snapshots] ORDER BY EndedOn DESC

but when I try this :

let
    Source = Sql.Database("mydatabase.local", "DataWarehouse", Query="SELECT TOP (1) *  FROM [DataWarehouse].[dbo].[Snapshots] ORDER BY EndedOn DESC"),
    dbo_Snapshots = Source{[Schema="dbo",Item="Snapshots"]}[Data]
in
    dbo_Snapshots

I got no result in PowerBI.

So I think I mess somewhere, but I can find it.

[DenisBergeron]

let
    Source = Sql.Database("mydatabase.local", "DataWarehouse", [Query="SELECT TOP (1) *  FROM [DataWarehouse].[dbo].[Snapshots] ORDER BY EndedOn DESC"]),
    dbo_Snapshots = Source{[Schema="dbo",Item="Snapshots"]}[Data]
in
    dbo_Snapshots

For some how, you need to write [ query ] didn't see this documented, but that how the automatic generation work.

Now, I just need to find how my other select can union with the snapshot ID.

[DenisBergeron · Accepted solution]

For future reference :

let
    Source = Sql.Database("MyDataBase.local", "DataWarehouse", [HierarchicalNavigation=true, MultiSubnetFailover=true, Query="
                Declare @SnapID VARCHAR(MAX);
                Declare @Instruction VARCHAR(MAX);
                SET @SnapID = (SELECT TOP (1) SnapShotId  FROM [DataWarehouse].[dbo].[Snapshots] ORDER BY EndedOn DESC);
                SELECT * FROM [DataWarehouse].[dbo].[MyTable]  Where SnapshotId in (@SnapID)"])
in
    Source

So simple, but so research 😉