在包含外部參考的彙總運算式中指定了多個資料行。如果要彙總的運算式包含了外部參考，則該外部參考必須是運算式中參考的唯一資料行。

Multiple columns are specified in an aggregated expression containing an outer reference. If an expression being aggregated contains an outer reference, then that outer reference must be the only column referenced in the expression.