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arpost
Post Prodigy
Post Prodigy

Is it possible to create a query from text?

I have a scenario where I need to generate a dynamic query and wondered if it is possible to do so by "creating" a query from text.

 

For example, if I had a text field that contained the following:

let
    Source = 1 = 1
in
    Source

could that then be executed as a query somehow?

arpost_0-1636500764736.png

 

1 ACCEPTED SOLUTION
mahoneypat
Microsoft Employee
Microsoft Employee

Yes.  You can use Expression.Evaluate("M expression") for that.

Expression.Evaluate - PowerQuery M | Microsoft Docs

 

Pat





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@mahoneypa HoosierBI on YouTube


View solution in original post

4 REPLIES 4
mahoneypat
Microsoft Employee
Microsoft Employee

Looks like you are missing the let and in parts of your query inside your Expression.Evaluate.

 

Pat

 





Did I answer your question? Mark my post as a solution! Kudos are also appreciated!

To learn more about Power BI, follow me on Twitter or subscribe on YouTube.


@mahoneypa HoosierBI on YouTube


That did the trick! It's a bummer the applied steps aren't listed using this method, but the method is great just the same. Appreciate it!

mahoneypat
Microsoft Employee
Microsoft Employee

Yes.  You can use Expression.Evaluate("M expression") for that.

Expression.Evaluate - PowerQuery M | Microsoft Docs

 

Pat





Did I answer your question? Mark my post as a solution! Kudos are also appreciated!

To learn more about Power BI, follow me on Twitter or subscribe on YouTube.


@mahoneypa HoosierBI on YouTube


Very cool! Didn't know about that function, @mahoneypat. Can this handle more complex queries? I keep getting an error when I try something like the following:

 

= Expression.Evaluate(    "Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText(""i45WclTSUTI0MFCK1YlWcgKyjaBsZyDbGMSOBQA="", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Name = _t, Value = _t]),
    #""Changed Type"" = Table.TransformColumnTypes(Source,{{""Name"", type text}, {""Value"", Int64.Type}}),
    #""Filtered Rows"" = Table.SelectRows(#""Changed Type"", each ([Name] = ""B""))""""")

Here's the original in the Advanced Editor:

 

arpost_0-1636507251114.png

and here's the original code:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WclTSUTI0MFCK1YlWcgKyjaBsZyDbGMSOBQA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Name = _t, Value = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Name", type text}, {"Value", Int64.Type}}),
    #"Filtered Rows" = Table.SelectRows(#"Changed Type", each ([Name] = "B"))
in
    #"Filtered Rows"

 

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