MS Access VB SQL Syntax for 3 Table Join

Question

I have been trying to create a form which contains information from 3 tables. On this form I would like to have a filter combo box so that the user may select a member type and it will filter the list to members with that member type.

Members in our database can have more than one type. For this reason I created a memberTable:

MemberID FName SName etc.

A membertype table:

MemberTypeID MemberTypeName

and a joining table membermembertype:

MemberID MemberTypeID

I have tried to set my form up with a number of different queries:

SELECT qryMemberType.MemberID, qryMemberType.FName, qryMemberType.SName, 
qryMemberType.MemberTypeName, qryMemberType.MemberTypeID FROM qryMemberType;

SELECT [member].[MemberID] AS [member_MemberID], [member].[FName], [member].[SName], 
[membertype].[MemberTypeID] AS [membertype_MemberTypeID], [membertype].[MemberTypeName], 
[membermembertype].[MemberID] AS [membermembertype_MemberID], [membermembertype].[MemberTypeID] 

SELECT [member].[MemberID] AS [member_MemberID], [member].[FName], [member].[SName], 
[membermembertype].[MemberID] AS [membermembertype_MemberID], 
[membermembertype].[MemberTypeID] AS [membermembertype_MemberTypeID], 
[membertype].[MemberTypeID] AS [membertype_MemberTypeID]

The VBA for the combo box that I have been attempting to filter with is:

Dim myMember As String
    
    myMember = "SELECT ... FROM ... WHERE ([MemberTypeID] = " & Me.cboMemberType & ");"
    Me.frmFilterTestSub.Form.RecordSource = myMember
    Me.frmFilterTestSub.Form.Requery

I have tried numerous different syntaxes for the SELECT statement in the VBA for the combo box including:

"Select * from membermembertype where ([MemberTypeID] = " & Me.cboMemberType & ")"

"SELECT member.MemberID AS member_memberID, member.FName, member.SName, 
        membertype.MemberTypeID AS membertype_MemberTypeID, membertype.MemberTypeName, 
        membermembertype.MemberID AS membermembertype_MemberID, 
        membermembertype.MemberTypeID AS membermembertype_MemberTypeID 
    FROM member 
    LEFT JOIN (membertype 
    RIGHT JOIN membermembertype ON membertype.[MemberTypeID] = membermembertype.[MemberTypeID])
        ON member.[MemberID] = membermembertype.[MemberID] 
    WHERE ([MemberTypeID] = " & Me.cboMemberType & ")"

"SELECT member.*, 
        (membermembertype.MemberID AS mmt_MemberID), 
        (membermembertype.MemberTypeID AS mmt_MemberTypeID), 
        membertype.MemberTypeName 
    FROM (member 
    LEFT JOIN membermembertype ON mmt_MemberID = (member.MemberID AS m_MemberID)) 
    RIGHT JOIN membertype ON mmt_MemberTypeID=(membertype.MemberTypeID AS mt_MemberTypeID) 
    WHERE ([MemberTypeID] = " & Me.cboMemberType & ");"

I'm pretty sure the first example returned the closest result with the list returning the correct number of records for each member type selected, however the fields were filled with the #Name? error value which is why I was trying to do a number of different ways to join the tables. The other SELECT STATEMENTS are returning SQL Syntax errors.

Any advice would be greatly appreciated!

Answer 1

Right outer join is highly frowned on in SQL, when you can use a left outer join in the correct order instead.

In your case, inner joins are better anyway.

You should use a parameter rather than string concatenation if you care about security, but since you're using Access I guess anyone with access to the file can already do what they like.

Please try this one and let me know if you get an error.

SELECT [Member].MemberId
, [Member].FName
, [Member].SName
, [MemberType].MemberTypeId
, [MemberType].MemberTypeName

FROM ((MemberType
INNER JOIN MemberMemberType ON MemberMemberType.MemberTypeId = MemberType.MemberTypeId)
INNER JOIN Member ON Member.MemberId = MemberMemberType.MemberId)

WHERE MemberType.MemberTypeId = 123 --Put your parameter here once you've tested that it works for a specific value

Answer 2

Since you only want to list the members, I guess that you are not really interested with membertype table info, then you can simply do this :

"SELECT member.MemberID AS member_memberID, member.FName, member.SName
 FROM member 
 INNER JOIN membermembertype 
   ON (membermembertype.[MemberTypeID] = " & Me.cboMemberType & " AND member.[MemberID]=membermembertype.[MemberID]) "