Question

SQL Syntax is still something I am learning. I am getting the error noted below the this snippet of code.

SELECT
 CASE  WHEN    LTRIM(RTRIM(cLehmanNo)) =' ' THEN NULL 
       WHEN cLehmanNo IS NOT NULL  THEN REPLACE ( cLehmanNo,SUBSTRING (cLehmanNo,PATINDEX( '%[^a-zA-Z0-9 '''''']%',cLehmanNo),1), ' ' )
 END asLOAN_NUMBER
,CASE  WHEN    LTRIM(RTRIM(cMERS)) =' ' THEN NULL 
       WHEN cMERS IS NOT NULL  THEN REPLACE ( cMERS,SUBSTRING (cMERS,PATINDEX( '%[^a-zA-Z0-9 '''''']%',cMERS),1), ' ' )
 END asMERS_ID

and 100+ more of same.

Msg 8133, Level 16, State 1, Line 1
None of the result expressions in a CASE specification can be NULL.

What am I doing wrong? How do I keep the gist of the statement and not get this crazy error?

Answer 1

This happens when it can’t infer the type.

e.g.

SELECT CASE WHEN 1 = 2 THEN NULL ELSE NULL END 

But this works

SELECT CASE WHEN 1 = 2 THEN NULL ELSE replace(NULL,'','') END

so I doubt the error is from the code you have shown us (You are using string functions and the following quick test shows that it will assume that to be varchar(8000))

SELECT CASE WHEN 1 = 2 THEN NULL ELSE REPLACE(NULL,'','') END a
INTO t /*Creates column of datatype varchar(8000)*/