SOLVED!!!:
OK - here's what I've come up with.
Assign numeric order to IC and PC values
I concatenated the IC & PC field values together and assigned values and added the ID of the records in the original subreport. I called this field HasIP
=Switch(Fields!IC.Value+Fields!PC.Value="YesYes", 1,
Fields!IC.Value+Fields!PC.Value="YesNo", 2,
Fields!IC.Value+Fields!PC.Value="NoNo", 3) & "-" & Fields!R_Name.Value
This left me with 2-xxxx, 1-yyyy etc.
I then added a filter to my second dataset:
=Left(Fields!HasIP.Value, 1)
to exclude values of "NoNo"
Concatenate HasIP and other fields in Dataset2 (to be used by LookupSet)
In addition also had to convert the text values into code for output (eg Yes = 1, No = 2, Unknown = 3 etc). I did this by creating a calculated field in Dataset2 (in the report, not the query) which included the HasIP. I delimited HasIP from the value by using a dollar sign.
=Fields!HasIP.Value & "$" &
SWITCH(
left(Fields!CoR.Value, 1)="C", 1,
Left(Fields!CoR.Value, 1)="N", 2,
True, ""
)
This left me with 2-xxxx$2, 1-yyyy$1 etc.
Sort the LookupSet results
LookupSet creates an array (and yes, now you know too). I needed to sort this so that the one I'm after is the first value returned. This is achieved by copying and pasting the following into the custom code section of your report. (I've added the code to allow you to sort in reverse if you need it).
Function JoinSorted(m_Array As Object()) As String()
System.Array.Sort(m_Array)
' Array.Reverse(m_Array) 'uncomment this line if you want to sort in reverse
Dim k As Integer = 0
For i As Integer = 0 To m_Array.Length - 1
If i > 0 AndAlso m_Array(i).Equals(m_Array(i - 1)) Then
Continue For
End If
m_Array(k) = m_Array(i)
k += 1
Next
Dim fred As [String]() = New [String](k - 1) {}
System.Array.Copy(m_Array, 0, fred, 0, k)
Return fred
End Function
You call this by using the following in your report expression:
Join(
Code.JoinSorted(
LookupSet(Fields!Main_ID.Value,Fields!Main_ID.Value,Fields!YourField.Value,"Dataset2")
),""
)
So, regardless of how LookupSet wanted to return the array, I always got 1-yyyy$1 first.
Handling LookupSet output on the report - include default for no records
For some LookupSet results in the report, I needed return a default value if there were no records returned. Otherwise I needed to return the assigned value (1, 2, 3 etc). If found two ways to do this.
This checks to see if the array count [yes, by using length] is greater than zero. If so, then using a mid function on the array result to return the 14th character:
=SWITCH(
LookupSet(
Fields!Main_ID.Value, Fields!Main_ID.Value, Fields!Record_Name.Value, "Dataset2"
)
.Length=0,
2,
LookupSet(
Fields!Main_ID.Value, Fields!Main_ID.Value, Fields!Record_Name.Value, "Dataset2")
.Length>0,
1)
OR
This is the same:
=iif(
LookupSet(
Fields!Main_ID.Value,Fields!Main_ID.Value,Fields!Main_ID.Value,"Dataset2"
).Length>0,
Mid(
Split(
Join(
Code.JoinSorted(
LookupSet(
Fields!Main_ID.Value,Fields!Main_ID.Value,Fields!Main_ID.Value,"Dataset2")
)
,";")
,";").GetValue(0)
, 'start point of mid
InStr(
Join(
Code.JoinSorted(
LookupSet(
Fields!Main_ID.Value,Fields!Main_ID.Value,Fields!Main_ID.Value,"Dataset2"
)
)
,";")
,"$")
+1,
1),
"2"
)
Handling LookupSet output on the report - using of MID when length of value varies
In some cases the value I needed to return varied in length, eg 2 or 10. I also needed to return nothing if the LookupSet didn't return any results. I couldn't use "normal" versions of MID like this:
Mid(
Join(Code.JoinSorted(
LookupSet(Fields!Main_ID.Value,Fields!Main_ID.Value,Fields!Q12d.Value,"Dataset2")),
";"),
InStr(
Join(
Code.JoinSorted(
LookupSet(Fields!Main_ID.Value,Fields!Main_ID.Value,Fields!Q12d.Value,"Dataset2")
),
";"),
"$")+1,
(
InStr(
Join(
Code.JoinSorted(
LookupSet(Fields!Main_ID.Value,Fields!Main_ID.Value,Fields!Q12d.Value,"Dataset2")
),
";"),
";")
-
InStr(
Join(
Code.JoinSorted(
LookupSet(Fields!Main_ID.Value,Fields!Main_ID.Value,Fields!Q12d.Value,"Dataset2")
),
";"),
"$")
- 1)
)
as it threw #ERROR due to the use of -1 (at the end) making the string a negative length for some records.
So, here is what I could use:
=
Mid(
Split(
Join(
Code.JoinSorted(
LookupSet(Fields!Main_ID.Value,Fields!Main_ID.Value,Fields!Q12b.Value,"Dataset2")
),
";"),
";").GetValue(0)
,
InStr(
Join(
Code.JoinSorted(
LookupSet(
Fields!Main_ID.Value,Fields!Main_ID.Value,Fields!Q12b.Value,"Dataset2")
),
";"),
"$")
+1,
1)
By doing this, I could get the results I was after in the details & the footer.
I hope this can help someone else.
