reporting-services - SSRS LookupSet - Join() 有效，但 Count() 无效

Question

这有效：

=IIf(
    Fields!EntityID.Value Is Nothing,
    Fields!Foo.Value,
    Join(
        LookupSet(
            Fields!EntityID.Value,
            Fields!EntityID.Value,
            Fields!Bar.Value,
            "dsMain"
        )
    , ",")
)

但这不会：

=IIf(
    Fields!EntityID.Value Is Nothing,
    Fields!Foo.Value,
    Count(
        LookupSet(
            Fields!EntityID.Value,
            Fields!EntityID.Value,
            Fields!Bar.Value,
            "dsMain"
        )
    )
)

我得到#Error，就像公式被破坏一样。它出什么问题了？

标签： reporting-services

Answer 1

您可以使用数组的 Length 属性来获取元素计数

=IIf(
    Fields!EntityId.Value Is Nothing,
    Fields!Foo.Value,
        LookupSet(
            Fields!EntityId.Value,
            Fields!EntityId.Value,
            Fields!Bar.Value,
            "dsMain"
        ).Length
)