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Byte.Type is a type facet in the Power Query M language. It represents one of the type claims belonging to ‘type number’. It is used primarily for handling small numerical values, often in binary data processing. The base type of ‘type number’ in Power Query is a general numeric type, but facets like Byte.Type provide additional details (such as representing 8-bit numeric values) to external systems or tools for effective data management.


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", Byte.Type }} )

Or when adding a column using Table.AddColumn:

Table.AddColumn( Source, "myColumn", 99, Byte.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 =  99,
   // Ascribes a type claim facet for 'type number'
  b = Value.ReplaceType( a, Byte.Type ),
  // Returns a table containing a value with the ascribed "Byte.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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