Question

I have a funny case where a piece of data needed, is actually embedded in a column of data looking something like this:
note that is a shop with strong legacy mess still in place.

adlu201008270919_3.zip the date is what i need and is embedded.

I have code to do this here:

AND CAST(SUBSTRING(M.MDS_FILE,5,4) + '-' +  SUBSTRING(M.MDS_FILE,9,2) + '-' +   SUBSTRING(M.MDS_FILE,11,2)  as datetime)

But now I find out that where you have here ‘adlu’ that is 4 pos. It can be 3 or 2 or 1.
So I have to code for that I have come up with this: but it’s not compiling:

AND CASE WHEN          WHEN CAST(SUBSTRING(M.MDS_FILE,5,4) + '-' +  SUBSTRING(M.MDS_FILE,9,2) + '-' +   SUBSTRING(M.MDS_FILE,11,2)  as datetime) 
ELSE WHEN OEN.LENGTH(S.FACILITY_KEY) = 3 THEN CAST(SUBSTRING(M.MDS_FILE,4,4) + '-' +  SUBSTRING(M.MDS_FILE,8,2) + '-' +   SUBSTRING(M.MDS_FILE,10,2)  as datetime)
ELSE WHEN OEN.LENGTH(S.FACILITY_KEY) = 2 THEN CAST(SUBSTRING(M.MDS_FILE,3,4) + '-' +  SUBSTRING(M.MDS_FILE,7,2) + '-' +   SUBSTRING(M.MDS_FILE,9,2)  as datetime)
ELSE CAST(SUBSTRING(M.MDS_FILE,2,4) + '-' +  SUBSTRING(M.MDS_FILE,6,2) + '-' +   SUBSTRING(M.MDS_FILE,8,2)  as datetime) END

Answer 1

CASE requires an evaluation. Your first statement just says WHEN(a bunch of conversions) but there’s never an evaluation (=, <, > etc).

I’m assuming you want that to be AND CASE WHEN OEN.LENGTH(s.FACILITY_KEY) = 4 THEN ...