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Type.Type is a type facet in the Power Query M language. It represents the default type claim for the ‘type type’. It is used primarily for interacting with external systems like Power BI, where meta-type information is beneficial. The base type of ‘type type’ in Power Query is a meta-type provide additional details (such as indicating the definition of types themselves) to external systems or tools.


Generally, you will face a facet when transforming column types. You can transform a column into the specified type by using Table.TransformColumnTypes:

Table.TransformColumnTypes( Source, {{ "myColumn", Type.Type }} )

Or when adding a column using Table.AddColumn:

Table.AddColumn( Source, "myColumn", type text, Type.Type" )

To inspect the kind of value you are dealing with, you can make use of the Table.Schema function. Applying it to a table returns a table with information about your columns. The Table.SingleRow function then transforms the result into a record, for easier reading.

  a =  type text,
   // Ascribes the default type claim facet for 'type type'
  b = Value.ReplaceType( a, Type.Type ),
  // Returns a table containing a value with the ascribed "Type.Type" 
  c = #table(type table [Col1 = Value.Type( b ) ], { b } ), 
  // Shows the Table information, including typeName and value kind
  d = Table.Schema( c ),
  // For easier viewing, return table as record
  e = Table.SingleRow( d )

Related facets

Other related facets are:

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