SQL Tables importing without associated data types

[jonoling]

Hi,

I have a fact table that I'm connecting to in SQL. When reviewing the INFORMATION_SCHEMA.COLUMNS query in SSMS for the table it shows the [order_date] field as being stored as a datetime data type which is correct:

However when importing this table into PBI Desktop all the datatypes are changed to Text in transit:

The only steps in the query are:

let
   Source = Sql.Database(sqlserver, db)
   Table = Source{[Schema="dbo",Item=tablename]}[Data]
in
   Table

I can convert the data types manually in Power Query but this prevents incremental refresh if we have to download the entire dataset, change types and then filter.

Have had a search around but couldn't find any reasons as to why this would occur. Would welcome ideas as to why this is happening, and how to resolve.

Thanks Power BI Community!

[UThomas]

Hello, I have the same issue with a MS SQL Database. There are a custom data type called (APdate) which is a datetime-Type, but PowerQuery didn't recognize it as datetime but set it to text.

I use the standard "From MS SQL Database"-Connector.

let
    Quelle = Sql.Databases("SQL1.xxx.de"),
    xxx = Quelle{[Name="xxx"]}[Data],
    dbo_yyy = xxx{[Schema="dbo",Item="LIEFRECHNUNG"]}[Data]
in
    dbo_LIEFRECHNUNG

select [$Table].[id] as [id],
    [$Table].[timestamp] as [timestamp],
    [$Table].[LIEFRECHNUNG] as [LIEFRECHNUNG],
    [$Table].[STATUS] as [STATUS],
    [$Table].[ADRESSE] as [ADRESSE],
    [$Table].[PERSONAL] as [PERSONAL],
    convert(nvarchar(max), [$Table].[RECHNUNGSDATUM]) as [RECHNUNGSDATUM],
    [$Table].[RECHNUNGSNR] as [RECHNUNGSNR],
    convert(nvarchar(max), [$Table].[DATUM]) as [DATUM],

if I change the M-code to:

let
    Quelle = Sql.Database("SQL1.xxx.de", "yyy", [Query="SELECT * from LIEFRECHNUNG"])
in
    Quelle

the columns typ is correct (datetime).

What's wrong with the first (out-of-the-box) M-Code?

Why isn't PowerQuery using the system data type from SQL-Server?

[lbendlin]

Anything suspicious on the Fiddler or Power Query Diagnostics?

[lbendlin]

which options parameters did you apply to your connector?  If this were a widespread problem we'd have heard about it by now.

[jonoling · Accepted solution]

None, it's the out of the box SQL Server connector from Power Query. The only inputs it's taking is the SQL string and DB, then navigating to the table in question. 

let
   Source = Sql.Database(sqlserver, db)
   Table = Source{[Schema="dbo",Item=tablename]}[Data]
in
   Table

 Agree, it doesn't seem to be a widespread issue, this is the first time I've come across an issue like this. Just tested with a sandbox WorldWideImporters DB and the native query generated brings through datatypes fine. 

Odd!

[lbendlin]

Run a fiddler trace and also check the query logs on your SQL server.  Maybe something is blocking the meta data calls?

[jonoling]

Looks like the issue is with the Power BI SQL Connector itself. Looking at the native query being sent, all fields are being converted to text data types:

Writing a custom SQL statement to select the data seems to bring across the right datatypes. I haven't come across documentation on why this occurs and how to turn it off yet though.