column_ifexists()

Takes a column name as a string and a default value. Returns a reference to the column if it exists, otherwise - returns the default value.

Syntax

column_ifexists(columnName,defaultValue)

Arguments

  • columnName: The name of the column
  • defaultValue: The value to use if the column doesn't exist in the context that the function was used in. This value can be any scalar expression (e.g. a reference to another column).

Returns

If columnName exists, then the column it refers to. Otherwise - defaultValue.

Examples

.create function with (docstring = "Wraps a table query that allows querying the table even if columnName doesn't exist ", folder="My Functions")
ColumnOrDefault(tableName:string, columnName:string)
{
	// There's no column "Capital" in "StormEvents", therefore, the State column will be used instead
	table(tableName) | project column_ifexists(columnName, State)
}


ColumnOrDefault("StormEvents", "Captial");