CODEWITHSUNDEEP
sqliisvbscriptasp-classicadodb
TMHDesign
TMHDesign

Reputation: 185

Why does an ADODB.Command Object throw - "Invalid use of Null: 'replace'"

I have some code that was using an ADODB.Recordset object to query a MariaDb database. In my query I am using coalesce such as this -

SELECT COALESCE(offers_owner.description, offers.description) AS description FROM
offers_owner LEFT JOIN websites on offers_owner.website_id = websites.id LEFT JOIN offers on
offers_owner.offer_id = offers.id WHERE offers_owner.id = 401

and in my code I have this -

If Not IsNull(rs("description")) or rs("description") <> "" Then
    response.write "<p class=" & chr(34) & "clear" & chr(34) & "><br />" & replace(replace(rs("description"),"company_name",session("company")),"company_city",session("city2")) & "<br /><br /></p>" & vbcrlf
end if

This works fine, and outputs as need be.

But, as soon as I switch to using an ADODB.Command object, I get an "invalid use of null". If I remove the conditional If Then, it does not throw and error.

Any idea as to why?

Thank you.

I tried to limit the conditionals in the IF Then statement

Upvotes: 0

Views: 165

Answers (2)

LukasKroess
LukasKroess

Reputation: 357

Assuming that your rs("description") yields null, then the condition in your question would compare null agains an empty string.

I could imagine, that that is the 'invalid use of null' from the error.

In the codesnippet from your answer, you comapre the .Value of rs("description") against the empty string. It is possible (very likely) that .Value always returns a string and is therefore allowed to be checked against the empty string.

As the comments to your answer have pointed out, it is vanishingly unlikely (if still tecnically possible) that the assignment to a var makes a difference.

Edit:

you could also solve the "null to empty string" problem in your mariadb query, by simply wrapping your COALESCE in to a IFNULL(COALESCE([...]), '')

Upvotes: 0

TMHDesign
TMHDesign

Reputation: 185

The way I solved this was to assign the value of the field in question to a variable, such as this:

description = myRS("description").value

if not isNULL(description) and description <> "" Then
replace(description,"xyz","abc")
end if

Upvotes: -1

Related Questions