错误时评估SSRS表达式

Question

In an SSRS report I have a field that has an expression that takes a name in "LastName, FirstName" format and puts it into "FirstInitial. LastName" if it contains a comma (this part always works). However, if the string does not contain a comma, it should just print the string, but instead the report displays "#Error":

=IIF(InStr(Fields!EmployeeName.Value, ", ") > 0, Mid(Fields!EmployeeName.Value, Instr(Fields!EmployeeName.Value, " ") + 1, 1) & ". " & Mid(Fields!EmployeeName.Value, 1, Instr(Fields!EmployeeName.Value, ",") - 1), Fields!EmployeeName.Value)

The weird part is that if I change the "true" logic to just have it print the string "contains comma", this expression works exactly as expected - a string of "LastNameOnly" produces "LastNameOnly" and the others print "contains comma". So it seems that even though the statement is false, it's still running the string through the "true" logic, despite it not being used, and throws an error.

I've tried having the string modifier be in the true and the false sections (and adjusting the evaluation statement accordingly) of the if statement and that doesn't seem to make a difference.

Has anyone ran into this / have a solution? Or maybe I'm missing something?? Thanks in advance!

Using SQL Server 2008, developing in BIDS extension for Visual Studio 2013

Answer 1

Apparently SSRS evaluates both the true and false conditions, regardless of which one it's going to use. The work around for this is to use VB custom code. Here is a link that shows you how to use VB in SSRS

http://dyslexicanaboko.blogspot.com/2012/11/ssrs-logical-flaws-of-iif.html

Hope this helps others!