Solved

Null values in my table are causing problems in my join query

Posted on 2011-03-08
12
416 Views
Last Modified: 2013-11-27
Hello,
I'm joining multiple tables to create a report.  It works fine unless I run into NULL values in the join statement.  What can I do to fix this?  Below is my query.


 strQuery = "SELECT Requests.*, RequestTypes.RequestTypeID, RequestType, [Approved/Unapproved].ID, [Approved/Unapproved].[Approved/Unapproved], " & _
                    "[Type of Leave].ID , TypeOfLeave " & _
                    "FROM Requests, RequestTypes, [Approved/Unapproved], [Type of Leave] " & _
                    "WHERE ((Requests.StartDate Between #" & strStartDate & "#" & " And #" & strEndDate & "#" & _
                    "OR Requests.EndDate Between #" & strStartDate & "#" & " And #" & strEndDate & "#)" & _
                    "AND Requests.Department = " & "'" & strDepartment & "'" & ")" & _
                    "AND Requests.RequestTypeID = RequestTypes.RequestTypeID " & _
                    "AND CInt(Requests.[Approved/Unapproved]) = [Approved/Unapproved].ID " & _
                    "AND CInt(Requests.[Request Type]) = [Type of Leave].ID " & _
                    "ORDER BY RequestID"

Open in new window


What's causing errors is when CInt(Requests.[Approved/Unapproved])  is NULL (this is a text field in my table).  And when CInt(Requests.[Request Type]) is NULL (this is also a text field in my table).

0
Comment
Question by:AronMcD
  • 5
  • 3
  • 3
  • +1
12 Comments
 
LVL 11

Expert Comment

by:N R
ID: 35071651
What fields and I can rewrite it for you, unless you know how do this.

isnull(fieldname,' ')
0
 
LVL 15

Expert Comment

by:derekkromm
ID: 35071697
In access, its actually Nz()

so if this line was giving you trouble:

 "AND Requests.Department = " & "'" & strDepartment & "'" & ")" & _

change it to this:

 "AND Nz(Requests.Department, '') = " & "'" & strDepartment & "'" & ")" & _
0
 
LVL 15

Expert Comment

by:derekkromm
ID: 35071699
0
Enterprise Mobility and BYOD For Dummies

Like “For Dummies” books, you can read this in whatever order you choose and learn about mobility and BYOD; and how to put a competitive mobile infrastructure in place. Developed for SMBs and large enterprises alike, you will find helpful use cases, planning, and implementation.

 

Author Comment

by:AronMcD
ID: 35071711
Gallitin,
Thank you for the quick response.  The fields that are causing me problems are in BOLD below.  The Requests.RequestTypeID is a Numeric field in my table.  I'm not sure if that will cause problems using isnull or not.  I'm not so much concerned about that though as that field is rarely left null.  Let me know if you need more.  Thanks.

strQuery = "SELECT Requests.*, RequestTypes.RequestTypeID, RequestType, [Approved/Unapproved].ID, [Approved/Unapproved].[Approved/Unapproved], " & _
                    "[Type of Leave].ID , TypeOfLeave " & _
                    "FROM Requests, RequestTypes, [Approved/Unapproved], [Type of Leave] " & _
                    "WHERE ((Requests.StartDate Between #" & strStartDate & "#" & " And #" & strEndDate & "#" & _
                    "OR Requests.EndDate Between #" & strStartDate & "#" & " And #" & strEndDate & "#)" & _
                    "AND Requests.Department = " & "'" & strDepartment & "'" & ")" & _
                    "AND Requests.RequestTypeID = RequestTypes.RequestTypeID " & _
                    "AND CInt(Requests.[Approved/Unapproved]) = [Approved/Unapproved].ID " & _
                    "AND CInt(Requests.[Request Type]) = [Type of Leave].ID " & _
                    "ORDER BY RequestID"
0
 
LVL 15

Expert Comment

by:derekkromm
ID: 35071724
"AND Nz(Requests.RequestTypeID, 0) = RequestTypes.RequestTypeID " & _
                    "AND Nz(CInt(Requests.[Approved/Unapproved]), 0) = [Approved/Unapproved].ID " & _
                    "AND Nz(CInt(Requests.[Request Type]), 0) = [Type of Leave].ID " & _
0
 
LVL 11

Expert Comment

by:N R
ID: 35071737
This is MS SQL
strQuery = "SELECT Requests.*, RequestTypes.RequestTypeID, RequestType, [Approved/Unapproved].ID, [Approved/Unapproved].[Approved/Unapproved], " & _
                    "[Type of Leave].ID , TypeOfLeave " & _
                    "FROM Requests, RequestTypes, [Approved/Unapproved], [Type of Leave] " & _
                    "WHERE ((Requests.StartDate Between #" & strStartDate & "#" & " And #" & strEndDate & "#" & _
                    "OR Requests.EndDate Between #" & strStartDate & "#" & " And #" & strEndDate & "#)" & _
                    "AND Requests.Department = " & "'" & strDepartment & "'" & ")" & _
                    "AND isnull(Requests.RequestTypeID,0) = RequestTypes.RequestTypeID " & _
                    "AND CInt(isnull(Requests.[Approved/Unapproved],0)) = [Approved/Unapproved].ID " & _
                    "AND CInt(isnull(Requests.[Request Type],0)) = [Type of Leave].ID " & _
                    "ORDER BY RequestID"

Open in new window

0
 
LVL 19

Expert Comment

by:MINDSUPERB
ID: 35071738
Try to use the Nz function:

CInt(Nz(Requests.[Approved/Unapproved],0))  

CInt(Nz(Requests.[Request Type],0))

Also check out the data type of your fields for it is uncommon to use the Cint to a text field format.

Sincerely,
Ed
0
 
LVL 11

Accepted Solution

by:
N R earned 500 total points
ID: 35071745
and then access if your using it.
strQuery = "SELECT Requests.*, RequestTypes.RequestTypeID, RequestType, [Approved/Unapproved].ID, [Approved/Unapproved].[Approved/Unapproved], " & _
                    "[Type of Leave].ID , TypeOfLeave " & _
                    "FROM Requests, RequestTypes, [Approved/Unapproved], [Type of Leave] " & _
                    "WHERE ((Requests.StartDate Between #" & strStartDate & "#" & " And #" & strEndDate & "#" & _
                    "OR Requests.EndDate Between #" & strStartDate & "#" & " And #" & strEndDate & "#)" & _
                    "AND Requests.Department = " & "'" & strDepartment & "'" & ")" & _
                    "AND nz(Requests.RequestTypeID,0) = RequestTypes.RequestTypeID " & _
                    "AND CInt(nz(Requests.[Approved/Unapproved],0)) = [Approved/Unapproved].ID " & _
                    "AND CInt(nz(Requests.[Request Type],0)) = [Type of Leave].ID " & _
                    "ORDER BY RequestID"

Open in new window

0
 

Author Comment

by:AronMcD
ID: 35071853
I copied and pasted Gallitan's code and while I'm not getting the error anymore, I'm not getting the record that I should be getting.  I'm going to keep testing....I'll get back to you.
0
 
LVL 15

Expert Comment

by:derekkromm
ID: 35071862
..did you try mine?
0
 
LVL 15

Expert Comment

by:derekkromm
ID: 35072199
i don't know why you completely ignored all my posts, considering i posted a correct solution twice...
0
 

Author Comment

by:AronMcD
ID: 35072200
Gallitin's code worked.  I was entering in the wrong values when testing..it's been a long day.  Anyway thanks to all of you.  I appreciate it.  
0

Featured Post

Networking for the Cloud Era

Join Microsoft and Riverbed for a discussion and demonstration of enhancements to SteelConnect:
-One-click orchestration and cloud connectivity in Azure environments
-Tight integration of SD-WAN and WAN optimization capabilities
-Scalability and resiliency equal to a data center

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

I'm trying, I really am. But I've seen so many wrong approaches involving date(time) boundaries I despair about my inability to explain it. I've seen quite a few recently that define a non-leap year as 364 days, or 366 days and the list goes on. …
This article describes how to use the timestamp of existing data in a database to allow Tableau to calculate the prior work day instead of relying on case statements or if statements to calculate the days of the week.
Familiarize people with the process of retrieving data from SQL Server using an Access pass-thru query. Microsoft Access is a very powerful client/server development tool. One of the ways that you can retrieve data from a SQL Server is by using a pa…
In Microsoft Access, learn different ways of passing a string value within a string argument. Also learn what a “Type Mis-match” error is about.

830 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question