RowExpression.From is a Power Query M function that returns the abstract syntax tree (AST) for a function’s body, normalized into a row expression. The function returns an AST if it can be generated, or an error otherwise.
Compatible with: Power BI Service Power BI Desktop Excel Microsoft 365
Syntax
RowExpression.From( function as function ) as recordDescription
Returns the abstract syntax tree (AST) for the body of function, normalized into a row expression:
- The function must be a 1-argument lambda.
- All references to the function parameter are replaced with
RowExpression.Row. - All references to columns are replaced with
RowExpression.Column(columnName). - The AST will be simplified to contain only nodes of the kinds:
ConstantInvocationUnaryBinaryIfFieldAccessNotImplemented
An error is raised if a row expression AST cannot be returned for the body of function.
Examples
Returns the AST for the body of the function each [CustomerID] = "ALFKI"
RowExpression.From( each [CustomerName] = "ALFKI" )
// Output:
[
Kind = "Binary",
Operator = "Equals"
Left = [ Kind = "FieldAccess", MemberName = "CustomerName", Expression = "Record" ]
Right = [ Kind = "Constant", Value = "ALFKI" ]
]Related functions
Other functions related to RowExpression.From are:
