I have a database which tracks employee QA. I'd like to be able to search by a single Staff Member, a whole team, or a Unit. I have three controls that correspond to those fields and only one can ever have a value at once. In my quesry I'd like to have threee expressions that will limit my results by one of those three fields. I'm adding just one to start and I've hit a problem.
I found this https://www.acuitytraining.co.uk/microsoft-training-courses/access/if-statements/ which seems to do what I want. Here is the code I'm trying.
IIf(IsNull([Forms]![MainMenu]![btnManagersMenu].[Form]![cmbStaffSelect]),
[UserLogin] Like "*",[UserLogin]=[Forms]![MainMenu]![btnManagersMenu].
[Form]![cmbStaffSelect])
Which works fine if the control has a value. (condition is false) If the dropdown has no value (condition is true) I get zero results. I suspect the problem lies with the Like "*" on my UserLogin field. Here is my query wizard and the buildler wizard for the IIF expression
Can anyone see why I'm not getting any results for the dropdown control being empty. To my thinking this should give me an unfiltered list of results. I have double checked my data and there are 137 records that should appear if I'm not limited by the staff selection.
The short version of this is if cmbStaffSelect has a value I want my records limited by that value. If cmbStaffSelect is blank I want to get all records.
Keep in mind that the iif function will always evaluate both the then and else arguments, before returning the appropriate value depending on the value returned when evaluating the supplied test expression.
As such, if either the then or else arguments have the potential to error when evaluated (regardless of the result of the evaluation of the test expression), then the iif expression has the potential to error.
As an alternative, you could use the Nz function to achieve the same result:
[UserLogin] LIKE Nz([Forms]![MainMenu]![btnManagersMenu].[Form]![cmbStaffSelect],"*")
Perhaps your IsNull([Forms]![MainMenu]![btnManagersMenu].[Form]![cmbStaffSelect]) is always returning false because cmbStaffSelect might be equal to empty string?
Try something like this:
IIf(Trim([Forms]![MainMenu]![btnManagersMenu].[Form]![cmbStaffSelect] & "") = "",
[UserLogin] Like "*",[UserLogin]=[Forms]![MainMenu]![btnManagersMenu].
[Form]![cmbStaffSelect])
This checks to see if the cmbStaffSelect is "" ... if cmbStaffSelect is null - it converts it to "" by appending an "" to the null value.
I believe your hunch is exactly correct. If you want your query result to return the * symbol for the UserLogin field; then alter your IIF statement to be: [UserLogin] = "*"
Related
I have a query that I control with some filtering options using a form. One of those filters is a medical code search. Sometime this field has a value and sometimes it is null. I want to be able to search for a partial string of data as well. The code I am trying is:
Expr9: ([tblQA].[Charges Entered]) Like Nz("*" & [Forms]![MainMenu]![btnManagersMenu].[Form]![txtChargeCode] & "*","*")
What I would like to have happen is if I enter some value in txtChargeCode that it will return any record with that string. That part works. The problem comes in when txtChargeCode has no value. If the record is null for Charges Entered then those records are filtered out of the results. I still see records that have a value. I want any null values for Charges Entered in the records to appear in the results, if txtChargeCode is left blank. Can anyone help me with whats going on here? I've read the Like and Nz pages so many times my eyes have crossed.
Your current criteria will never be null because it will always include the string "**".
Instead, we will use Nz to convert null values in [Charges Entered] into empty strings (""). Now that all items in [Charges Entered] are considered to be strings in the criteria, we can compare them with the LIKE operator.
The expression below will return all records (including nulls) when txtChargeCode is blank.
Nz([tblQA].[Charges Entered], "") Like "*" & [Forms]![MainMenu]![btnManagersMenu].[Form]![txtChargeCode] & "*"
You could sort [Charges Entered] so nulls are displayed at the top of the results to make it easier to spot nulls when txtChargeCode is empty.
I'm trying to make a MS Access report, where I use a text box to display a field value, then have another text box indicating if the first value is higher or lower than an entry in a separate table.
The report has a record source of "Table 1", and a textbox named "txt_Value1" which displays the number in Field: "Value1". I have a second table, "Customer_Criteria" which has a field "PassValue" that I want to compare against. My expression builder statement is:
IIf([txt_Value1]<(DLookUp("[PassValue]","[Customer_Criteria]","[Customer] = 'ABC'")),"TRUE","FALSE")
This statement always returns false, regardless of what the correct logical result is.
I've tested it, writing:
IIf(1<(DLookUp("[PassValue]","[Customer_Criteria]","[Customer] = 'ABC'")),"TRUE","FALSE")
And I get the correct results. Also, if I write:
IIf([txt_Value1]< 1,"TRUE","FALSE")
I get the correct results. What am I missing to compare the textbox value vs. the Dlookup?
As I understand, both fields are numeric. Access may consider those fields as text, so for correct comparing use type conversion.
Try this:
IIf(CLng(Nz([txt_Value1],0))< _
CLng(Nz(DLookUp("[PassValue]","[Customer_Criteria]","[Customer] = 'ABC'"),0)), _
"TRUE","FALSE")
Nz required if fields may contain NULL values, in this case type conversion function will return error.
I'm very confused by this situation, i've written quite a few IIF statements and always get them to work. I have two columns in my dataset called CATEGORY and PCT, what i'm trying to do is return the PCT value for only one specific value in CATEGORY.
For example, I have the following table of data
Category PCT
A .50
B .75
I have placed a textbox on my report and have written the following expression to return the PCT value if Category = B, like so:
=IIF(Fields!Category.Value = "B", Fields!PCT.Value, " ")
For some reason this expression returns empty every single time. When I just put Fields!Category.Value in the textbox as a test then the value A returns which is as expected.
I'm really thrown-off by this and I know i'm missing something very simple - can someone help?
Its important that we understand the context of the textbox as the expression seems valid.
If you placed a single textbox on your report and used your above expression (with references to the datasets) ONLY the first row of your dataset will be evaluated. In which case the expression will always evaluate to the same result.
Can you confirm that the control you are using is indeed a textbox? If it is then i believe you do need a reference to the dataset and the expression will look more like this:
=iif(First(Fields!Category.Value, "datasetName") = "B", First(Fields!PCT.Value, "datasetName"), " ")
This would only evaluate the first row in your dataset.
If you were to do this in a tablix using your original expression then it should work.
I've written a report for SSRS and Im using dataset filters with expressions to filter the report info. I seem to either have this expression wrong or the filter is not working correctly:
=IIf(Parameters!DoctorID.Value = "All" Or Parameters!DoctorID.Value = "", "*", Parameters!DoctorID.Value)
What I want to accomplish with the above code is if DoctorID = ALL or "" (blank) then I want to omit it from the filters so I return information for all doctors. However, whenever the value of DoctorID = ALL, I'm returning no rows what so ever. It should be the case that i'm getting ALL rows since DoctorID is not a specific number.
Does the "*" (star) not denote an omitting of that filter? Am I doing something wrong here?
Thanks!
The filter formula you provide is only half the equation: what is the operator and what are you comparing this to? And yes, I haven't seen SSRS use asterisk as a wildcard.
Consider putting your filter into the query for the dataset. The SQL WHERE clause can get pretty powerful. I would write your filter into the query as
...
WHERE
#DoctorID = 'All' OR #DoctorID = ''
OR #DoctorID = myTable.DoctorID
This will also let you move to a multiple value parameter pretty easily.
I have a textbox in my SSRS 2005 report. The expresssion for this textbox is:
=IIF(IsDBNull(Fields!fOrgID), Code.SetMyVar("null"), Code.SetMyVar(Fields!fOrgID.Value))
I have also tried IsNothing(Fields!fOrgID) and a few other variations of checking for nulls.
I have modified the SetMyVar function for testing and it now looks like this:
Public Function SetMyVar (var as String)
MsgBox(var, VbOKCancel, "Test1")
If var Is Nothing Then
Return "NOTHING"
Else
MyVar = var
Return var
End If
End Function
I also have the public variable MyVar:
Public Shared Dim MyVar as String
When my database query returns data, this correctly evaluates, a messagebox is displayed with the value, the textbox gets set with the value, and the world is generally a happier place.
When my database query does not return a value though, I get the error:
The query returned no rows for the data set. The expression therefore
evaluates to null.
and the SetMyVar function never appears to be ran (you never get the messagebox popup). As expected, my emotions range from anger, sadness, and bitter hatred of SSRS.
I read something about SSRS evaluating both sides of an IF statement, so perhaps that is why I get the error (likely then on Code.SetMyVar(Fields!fOrgID.Value))... not sure how I get around that though.
Thoughts? Suggestions? Words of comfort?
From the sound of things, it seems likely that the issue is that SSRS is having a problem displaying zero records. I'd recommend one of the following:
1) Use a control that handles zero records appropriately (Tables do. I think Lists do as well).
2) Modify your query to return a single record with blank values if it would otherwise return zero records.
An answer to the original question:
=IIF(IsNothing(Fields!fOrgID),
Code.SetMyVar("null"),
Code.SetMyVar(IIF(IsNothing(Fields!fOrgID),"Foo",Fields!fOrgID.Value)))
The error was from both sides of IIF being evaluated. The extra IIF in the statement above will avoid Code.SetMyVar from ever being called with a null value.
I believe you're right about about Iif always evaluating both of its value arguments (at least, it does in Visual Basic). I'm not sure why you're getting this precise error (unless strings can't be assigned a value of DBNull?), but you almost certainly want to attack this problem with a different method.
The reason for this is that your current code will likely always call both set methods regardless of the conditional value.
Formula that worked for my SSRS 2008 reports.
=IIf(String.IsNullOrEmpty(Fields!NullableFieldwithPossibleBlankStrings.Value),"Yes","No")
I tried this too (also tried a version with IsNothing)...
=Code.SetField(IsDBNull(Fields!fOrgID))
And changed the function to be one that accepts a boolean. I figure this above function would always return a true or false, but in the event of a NULL, I again get "The query returned no rows for the data set. The expression therefore evaluates to null.".
I need to pass back to my code if the field is null or not (as this will let me know if the datasource is null or not).
Let me know if you can think of a better way because I cannot.