RowExpression.From

Επιστρέφει το αφηρημένο δέντρο σύνταξης (AST) για το σώμα μιας συνάρτησης.

Syntax

RowExpression.From(
    function as function
) as record

Remarks

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:
  • Constant
  • Invocation
  • Unary
  • Binary
  • If
  • FieldAccess

An error is raised if a row expression AST cannot be returned for the body of function.

This function is identical to ItemExpression.From.

Examples

Example #1

Returns the AST for the body of the function each [CustomerID] = "ALFKI".

RowExpression.From(each [CustomerName] = "ALFKI")

Result:

[
    Kind = "Binary",
    Operator = "Equals",
    Left = RowExpression.Column("CustomerName"),
    Right =
    [
        Kind = "Constant",
        Value = "ALFKI"
    ]
]

Category

Table.Table construction