Forum Discussion
SQL Server Datatype -> Power Query Fixed decimal number ($)
Hi BA_Pete ,
It appears that the Value.NativeQuery does not work as I expected.
Created and populated a small test table.
CREATE TABLE [ref].[TestTable](
[MoneyDEF] [MONEY] NOT NULL,
[SmallMoneyDef] [SMALLMONEY] NOT NULL,
[DecimalDef] [DECIMAL](19, 4) NOT NULL,
[NumericDef] [NUMERIC](19, 4) NOT NULL,
[FloatDef] [FLOAT] NOT NULL
) ON [PRIMARY]
The following M gives the desired results in that the MONEY/SMALLMONEY columns are imported FIXED DECIMAL the others as FLOAT
let
Source = Sql.Database("myServer", "myDatabase"),
ref_TestTable = Source{[Schema="ref",Item="TestTable"]}[Data]
in
ref_TestTable
I have been using Value.NativeQuery, which for some reason - as yet to be determined - does not import the MONEY/SMALLMONEY as FIXED DECIMAL all columns are FLOAT
let
Source = Sql.Databases(Server),
db = Source{[Name = Database]}[Data],
TestTable = Value.NativeQuery(
db,
"SELECT
[MoneyDEF],
[SmallMoneyDef],
[DecimalDef],
[NumericDef]
FROM [ref].[TestTable]",
null,
[EnableFolding = true]
)
in
TestTable
The first workaround is not to use Value.NativeQuery but this outcome is a little surprising to me.
Will try and look more into Value.NativeQuery.
Regards,
B
Hi Pete,
I agree - for the reason you gave - that it is possibly the case that there isn't a direct equivalent that can pass from SQL to PQ as currency datatype.
The datatype conversion needs to be done, because the rounding issues of Fixed Decimal are not acceptable to our users, so the Currency datatype is implemented.
Regards,
B
Super UserHi Anonymous ,
If it's rounding of the values that's the problem, then you can use the Number.Round~ family of functions in Power Query. There's a few different types you can use, and each have different arguments you can use to get exactly the behaviour you need:
https://docs.microsoft.com/en-us/powerquery-m/number-round
I believe all of these functions will fold to SQL Server.
Pete
Hi BA_Pete,
I think that this article explains the requirement for the Fixed Decimal rather than Floating Point better than I can.
Choosing Numeric Data Types in DAX - SQLBI
Regards,
B
- BA_Pete
Hi Anonymous ,
Thanks for sharing the article, this makes sense.
Based on my own tests, both CASTing and CONVERTing numerical values to the SQL MONEY data type on SQL Server imports into Power Query correctly as the PQ Fixed Decimal data type:
As such, I think there's two possible issues:
1) PQ is applying an automatic data type evaluation on import, for some reason (SQL Server is classified as a 'Structured Source', so this should never happen, but just in case). You would see this as an auto-generated 'Changed Types' step under your Source/Navigation steps and this should be deleted to revert back to the source data types.
2) Your source data isn't being held as MONEY type in the database. This, as above, can be corrected using either CAST or CONVERT on these fields in the DB. However, the question would remain as to whether you are actually getting the data accuracy/integrity that you desire, when the values aren't even being stored in the DB as this data type.
Pete
Hi BA_Pete ,
It appears that the Value.NativeQuery does not work as I expected.
Created and populated a small test table.
CREATE TABLE [ref].[TestTable](
[MoneyDEF] [MONEY] NOT NULL,
[SmallMoneyDef] [SMALLMONEY] NOT NULL,
[DecimalDef] [DECIMAL](19, 4) NOT NULL,
[NumericDef] [NUMERIC](19, 4) NOT NULL,
[FloatDef] [FLOAT] NOT NULL
) ON [PRIMARY]
The following M gives the desired results in that the MONEY/SMALLMONEY columns are imported FIXED DECIMAL the others as FLOAT
let
Source = Sql.Database("myServer", "myDatabase"),
ref_TestTable = Source{[Schema="ref",Item="TestTable"]}[Data]
in
ref_TestTable
I have been using Value.NativeQuery, which for some reason - as yet to be determined - does not import the MONEY/SMALLMONEY as FIXED DECIMAL all columns are FLOAT
let
Source = Sql.Databases(Server),
db = Source{[Name = Database]}[Data],
TestTable = Value.NativeQuery(
db,
"SELECT
[MoneyDEF],
[SmallMoneyDef],
[DecimalDef],
[NumericDef]
FROM [ref].[TestTable]",
null,
[EnableFolding = true]
)
in
TestTable
The first workaround is not to use Value.NativeQuery but this outcome is a little surprising to me.
Will try and look more into Value.NativeQuery.
Regards,
B