Dealing With Null Values When Trying To Average Across Fields
Jan 20, 2012
I have a large amount of field data that was taken by a data logger. Specifically, The datalogger has five temperature probes embedded in soil, and takes a measurement automatically once every hour for each probe. So the table has a Time field, and then a Temp1, Temp2,... Temp5 field. I need to be able to average the temperature fields. This within itself is easy enough, I just tell the query to find (Temp1+Temp2+...+Temp5)/5. However, unfortunately, because it is field data is is very common for one (or more) of the ports to be malfunctioning at any one measurement time for a number of reasons.
If, for instance, Port one does not have a value, then the formula I entered will not work, as it can't add a null value to numbers, and otherwise It would be dividing by five whereas there were only four values to average.
I am in desperate need of some advice. Today I set to work building some math functions in my queries to calculate delays/turnaround times for work, etc.
I have found that where there are null values in my table - the calculation seems to break down.
Let me explain...
In it's simplest form (I have removed some fields and will deal with DATE only, not TIME which is a seperate field) I have the following -
I am trying to use the expression below to transpose strings of 4-6 numbers (140504) to a string of 8 numbers with "20" in front (20140504). Some of the [Receive_Date] fields are empty or are 0, and in those cases, I need the expression to return a null value.
The Format(...) part of the expression works fine on its own, but I am new to dealing with null values in my expressions, and when I add the rest of the expression, all '#Error' values are returned.
I have a query that performs some calculations, these calculations feed into another query and produce a final value. If there are no null values everything works perfectly. But when there are null values, I get errors.
What I have tried:
1) I tried to implement the Nz function for each field of the formula that is not calculated but from user input.
2) I tried to implement the Nz function for just the field that calculated the last result before feeding into the next query, but it didn't show the 0 value I gave.
3) I tried to use UPDATE TABLE SET in SQL, but I don't think I was using it right. I tried to use it for all records but always got an error when it ran.
The first two above result in showing no values at all, even if there are some. The third didn't work. How to easily update null values in the query to 0? All I could think of was to somehow use Criteria or SQL.
I have a query which returns, among other things, a number of boolean fields. In some cases, there will be a genuine True or False value in each of these fields; in others, it can and should be Null (e.g. as a result of a 'failed' LEFT JOIN of some description, where there is no associated record in the joined table which fulfills the criteria)
So something like this :
Code: SELECT [tblTable2].[fldBooleanField].... FROM [tblTable1] LEFT JOIN [tblTable2] ON [tblTable1].[SomeID] = [tblTable2].[SomeID]
However, I will be writing the result of the query to a text file and here's the problem. I want to show a numeric value for a genuine True / False (i.e. -1 and 0 respectively using the standard boolean conversions in Access) and a blank for any Null values.
So I tried this :
Code: SELECT CInt([tblTable2].[fldBooleanField]) AS fldBooleanField.... FROM [tblTable1] LEFT JOIN [tblTable2] ON [tblTable1].[SomeID] = [tblTable2].[SomeID]
However, currently when I look at the exported recordset in Notepad, I am getting 0's for both False and Null values (and -1 for True)
How I can adapt my query to keep Nulls...null? And convert the genuinely present boolean values to integer form?
Only thing I can think of is to use (untested) :
Code: IIf([tblTable2].[fldBooleanField] Is Null, Null, CInt([tblTable2].[fldBooleanField]))
But there's a number of boolean fields in there, all requiring the same treatment.
It might be an easy one but I just wasted the past hour deciphering through my code in order to solve the run-time error '94' that I'm getting when trying to execute the following code:
Code: Private Sub cmdUpdateDates_Click() '################################### 'This sub aims at combining the timesheet date and the start and end time into the fields [Start Time] and [End Time]. '################################### Dim intCounter As Integer intCounter = 0 Dim rs As ADODB.Recordset
Code: SELECT Avg(Round([Final 205].[LastOfSumOfRehLOS],2)) AS AvgInpLOS, Avg(Round([LastOfSumOfWaitLOS],1)) AS AvgWaitTime, Count([Final 205].PHN) AS Observations, [Final 205].LastOfIntensity AS Intensity_Level FROM [Final 205] GROUP BY [Final 205].LastOfIntensity;
It doesn't found the result to two decimal places.
I have 4 texts fields [DEVICE INSTALL] , [INSTRUMENT STAND], [BRACKETS RACEWAY SUPPORTS], [TUBING CAPILLARY] all can be either a percentage from 1-100 or "N/A" except [DEVICE INSTALL].I would like to calculate the [percentage complete]
my calculation in the field is as follows: ([DEVICE INSTALL]+ IIf([INSTRUMENT STAND]="N/A",100,[INSTRUMENT STAND])+ IIf([TUBING CAPILLARY]="N/A",100,[TUBING CAPILLARY])+ IIf([BRACKETS RACEWAY SUPPORTS]="N/A",100,[BRACKETS RACEWAY SUPPORTS])) /4
this seems to work to a degree. but for some reason when the [INSTRUMENT STAND] value is not "N/A" the percentage calculated is a wacky value much higher than 100. how could I possibly change my division #?
I have a query where data is first sorted by user input; first field's criteria: [fieldname], then by another field's criteria: Is Null.
I know there are records containing null values in the second field, as I have run a select query with the criteria: Like "*", to make sure they are null, and not zero-length-strings.
I want to calculate the average of 16 anodes from text box into the "average drop" box and simultaneously want the data to be saved in the table too as one of the fields. Also, How to load form view while the database loads?
I am trying to find an average of four fields in either a form or query. Basically I have figures for [Grade 1], [Grade 2] but [Grade 3] is an empty field. I need to include all three field because there are sometimes 3 grades, but a majority are 2 grades. How to do so?
I want query to show all results including any null values because at the moment it just misses the null values out.
So for example instead of the query saying that Fruiterer A has 5 apples, 0 oranges and 4 bananas it just says that Fruiterer A has 5 apples and 4 bananas. Therefore because oranges was a null value then it simply makes no reference to oranges.
I have two tables called table1 and table2 with following fields:
Table1: Name NameId
Table2: Name NameID Visits
where name and nameid is same but visit can me 0 to 230. name in table2 is same as table2 but only showing visit 1 or higher. How can I make new table that can list all name, nameId and visits.
I can create new table but it shows only table2's record. so all I need is table1 and table2 record if names are missing in table2 then put 0.
Hi all I have 3 linked tables in a vehicle database. 1 keeps a record of Service Due date, 1 has the Fleet numbers and the last contains Vehicle Condition reports. They are linked by the Fleet numbers. I have a query that returns the Services due between 2 dates. What I would like is to have the same query return any outstanding Vehicle Condition items as well for any Vehicles due for servicing. Currently, I can include the field in the query but if there are no current items for a vehicle in the Vehicle Condition table then the query does not return that vehicle as a result. Any suggestions would be appreciated.
Now I want to count the number of sales completed from these totals. However, as Dept 3 has no sales completed for October it does not show in the query. So I get
Dept 1 - 7 Dept 2 - 2 Dept 4 - 6
Any idea how to get Dept 3 - 0 to show up in the query?
I've found several threads on this subject, but I still can't get it to work, so please forgive me if I seem to be duplicating a question.
I'm making a very simple db. It has only 2 tables: MATERIAL (one) TEST RESULTS (many) with left join.
I need to report average test results (by MATERIAL) weekly, even if there were no tests for a particular product that week, ie;
MATERIAL A = 100 MATERIAL B = 90 MATERIAL C = MATERIAL D = 105
When I try to query, I only get results for A, B and D. It seems to be ignoring the MATERIAL table and looking only at the TEST RESULTS table.
I'm sure it's something simple that I'm overlooking but how do I get C to show, even if it has no results.
Here's my query SQL.:
SELECT DISTINCTROW [MATERIAL Query].MATERIAL, Avg([TEST RESULTS].V50) AS [Avg Of V50] FROM [MATERIAL Query] LEFT JOIN [TEST RESULTS] ON [MATERIAL Query].MATERIAL = [TEST RESULTS].MATERIAL WHERE ((([TEST RESULTS].[TEST DATE]) Between [Forms]![Date Range Form]![Start Date] And [Forms]![Date Range Form]![END DATE])) GROUP BY [MATERIAL Query].MATERIAL;
I am trying to build a query that combines several fields. The situation is as follows....
1. If a is > b then i need a 2. If b is > a then i need b 3. If a is null then b is not null 4. If b is null then a if a is not null 5. If a and b are null then '999999'
I have everything taken care of up to If 4. The problem i am having is that when create the sql language for 5 it is adding 999999 to the filed when step 3 or 4 are the case. See languange below.
Any help would be greatly appreciated.
IIf(MSC.[TDS<2500_S_GW_NR_100xGWMSC_mg/kg]>MSC.[TDS<2500_S_GW_NR_Model_mg/kg],MSC.[TDS<2500_S_GW_NR_100xGWMSC_mg/kg]) & IIf(MSC.[TDS<2500_S_GW_NR_Model_mg/kg]>MSC.[TDS<2500_S_GW_NR_100xGWMSC_mg/kg],MSC.[TDS<2500_S_GW_NR_Model_mg/kg]) & IIf(MSC.[TDS<2500_S_GW_NR_100xGWMSC_mg/kg] Is Null,MSC.[TDS<2500_S_GW_NR_Model_mg/kg]) & IIf(MSC.[TDS<2500_S_GW_NR_Model_mg/kg] Is Null,MSC.[TDS<2500_S_GW_NR_100xGWMSC_mg/kg]) & IIf(MSC.[TDS<2500_S_GW_NR_100xGWMSC_mg/kg],MSC.[TDS<2500_S_GW_NR_Model_mg/kg] Is Null,'999999') AS MSC_SGW
I have a series of values within a table that includes a number of null values. I would like to include this field within a query, however if the value is null I would like to show a 0, if the field is not null, I would like it to show the original value.
I have tried to use the IsNull in an iif formula without luck.
PS: If I was conducting this in Excel I would use the following =IF(J3="",0,J3)
I have a query set up to sum 2 fields to a 3rd field, for example, I have field1, field2, and field3. Fields 1 and 2 are data from a table. In Field3 I have an expression: Field3: [Field1] + [Field2] This works fine except when either Field1 and/or Field2 contain no data, then the sum does not work. Any ideas how to correct this? I realize this may not be the best way to accomplish what I am trying to do but this is a small part of a very large application and i would like to change as little as possible since everything else is working ok. Thanks very much.
hello friends, I have written an insert query but sometime it does not work properly and leave some column blank. I want to write a query which should check for the blank columns and delete these records.thanks in advance
I currently have a crosstab query that compares data for two years. The results look like this.
month 2004 2005 January 98% 95% ..... Decemeber 98
What I am getting at is that the query returns null values for the fields that do not have data recorded for the months in 2005 because we have not reached them yet. Is there a way for me to make sure that at least the value 0 is entered in the null value areas?
I need to create a query with the MTD field I have created the MTD and it works!!! but now I need it to show all of the PartNum fields even if null. do I need to convert all nulls to zeros? if so how do I go about this?
Here are the fields in the query
First Field: Field: PartNum Table: Part Total: Group By
Second Field: Field: UnitPrice Table: OrderDetail Total: Group By
Third Field: Field: NumOrdered Table: OrderDetail Total: Sum
Fifth Field: Field: CurrentYear: Year([OrderDate]) Table: (blank) Total: Group By Criteria: Year(Date())
Sixth Field: Field: CurrentMonth: Month([OrderDate]) Table: (blank) Total: Group By Criteria: Month(Date())
When I run the query I only get 2 parts and their total. but I want all parts to show up even if they have not been ordered in the month. the parts that have not been ordered should say $0.00 in the MTD field.
