Type.Union is a Power Query M function that computes the union of the types in the input list. The function returns a new type that represents the union of the input types.
Compatible with: Power BI Service Power BI Desktop Excel Microsoft 365
Syntax
Type.Union( types as list ) as typeDescription
The Type.Union function returns a type value that is a combination of two types. When possible, the operation returns the same type. For instance when combining two table types, or two record types. Trying to combine type null with another type usually results in the nullable form of the type. When you combine values that can’t easily be merged, the function may return type any.
Examples
Suppose you have two record types that you want to combine. Power Query can merge those into a single record type.
// Output: type [ A = text, B = number ]
let
type1 = type [ A = text ],
type2 = type [ B = number ],
combinedRecord = Type.Union( { type1, type2 } )
in
combinedRecord When you combine different types with null, the operation will try to give you a nullable type.
// Output: type { nullable number }
let
type1 = type { number },
type2 = type null,
combinedRecord = Type.Union( { type1, type2 } )
in
combinedRecordHowever, in situations where a type is not of the same sort and can’t be merged into the same type.
// Output: type any
let
type1 = type {number},
type2 = type [ B = number ],
combinedRecord = Type.Union( { type1, type2 } )
in
combinedRecordRelated functions
Other functions related to Type.Union are:
