I'm trying to annualise my data in tableau, but get an error in the Calculated Field.
"Cannot mix aggregate and non-aggregate arguments to function"
my formula is
sum(profit)/month(selected date) *12
How do I get an integer for the current month? That seems to be the problem, it tries to aggregate the month as well.
Thanks.
Short answer: wrap the call to month in a call to min() -- which works well if you have MONTH([selected date]) on the visualization as a dimension.
There are three types of calculated fields in Tableau:
row level calculations which act on a single data row. They can read from values of other fields in the same row and return a single value per row.
aggregate calculations which act on a partition or block of data rows. They can reference the result of aggregating the values for a field across the entire partition, using a an aggregate function like SUM() or MIN().
table calculations which act on an entire table of aggregated results.
You can't mix and match. Everything in a calculated field must be all at one level or another -- either all referenced fields must use aggregation functions (for aggregate calculated fields) or no referenced fields must use aggregation functions (for data row level calculated fields).
Hence the error message you saw.
Sometimes you know that all values for a field will be the same in a partition based on your visualization, so the aggregation function seems unnecessary. But Tableau still requires you to be explicit about how to turn a block of values into a single value, because the calculation must be defined even when the visualization is partitioned differently. In these cases, you can use min(), max(), avg(), or perhaps attr() because they all return the same value for a list of identical values.
The first two types are typically executed on the server (i.e. they are implemented by Tableau emitting SQL to send to the database server). Table calculations are executed by Tableau on the client site to post-process the results from the database server.
Table calcs are the most complicated type, but can be very useful. Explaining them is a post for another day.
Related
I am try to add up columns to get sum of sales made over years
how to achieve this dynamically without adding manually like
F.sum(2015,2016...)
SUM() is an aggregation function, it works column-wise not row-wise. To add results across rows simply use + e.g.
(`2015`+`2016`+...)
Having said all of that if your objective is to support the operation in a dynamic way. I suggest normalising your data (columns to rows) so the year becomes a single column with values of 2015,2016,... Doing so will allow you employ the SUM() function on the year column.
Working with denormalised data is generally bad practice for all sorts of reasons and only usually employed in the final output for display/presentation purposes. i.e. poor support for changing data (such as a new year value being added).
You can normalise the data using the STACK() function
I am trying to add a column to a collection by multiplying the 0.9 to existing database column recycling. but I get a run time error.
I tried to multiply 0.9 direction in the function but it is showing error, so I created the class and multiplied it there yet no use. what could be the problem?
Your error message is telling you what the problem is: your database query is using GROUP BY in an invalid way.
It doesn't make sense to group by one column and then select other columns (you've selected all columns in your case); what values would they contain, since you haven't grouped by them as well (and get one row returned per group)? You either have to group by all the columns you're selecting for, and/or use aggregates such as SUM for the non-grouped columns.
Perhaps you meant to ORDER BY that column (orderBy(dt.recycling.asc()) if ascending order in QueryDSL format), or to select all rows with a particular value of that column (where(dt.recycling.eq(55)) for example)?
I have my tableau workbook and I'm currently counting by a field called ID - COUNT([Id]) - while this is great, on days with no activity my dashboard doesn't show ANYTHING and I want it to show zero if there was no activity - so I do I change this to count but also replace null with 0 (zero)?
First make sure you understand what Count([ID]) does. It returns the number records in the data source that have a non-null value in the column [ID].
Count() never evaluates to null. But if you have no rows at all in your data after filtering, then you'll get an empty result set -- i.e. view data will not have any summary data to show at all - whether null or zero.
Wrapping COUNT() in a call to ISNULL() or ZN() won't help in that case.
The solution is to make sure you have at least one data row per day, even if all other fields besides the date are null. Aggregation functions ignore nulls so padding your data like this should not disturb your results. The simplest way is to make a calendar table that has one row per day with nulls in most columns. Then use a Union to combine the calendar with your original data source. Then Count(ID) will return zero on days where there are no other records besides the calendar entry.
You can also get similar results using data blending, although with a bit more complexity.
My end goal is to have a box change color when the last 3 records input into a field (based on the time of input) in FileMaker achieve a certain criteria (ex. variance < 2). I would like to know how to make this happen, or how a calculation/script can be written to only look at the last 3 records.
There are several ways you could approach this. A simple one would be to use a script to:
Show all records in the given table;
Unsort them (assuming they were entered in chronological order; otherwise sort them by creation timestamp);
Omit all records except the last three;
Get the value of a summary field defined as Standard Deviation of your value field;
Set a global variable/field to the square of the returned value.
Then use the global variable/field to conditionally format your "box".
If you don't want to use a script, you will have to define a relationship in order to get the last three values in the table, regardless of the current found set and/or sort order. Or you may use the ExecuteSQL() function for this.
A record in a table contains a range of valid dates, say:
*tbl1.start_date* and *tbl1.end_date*. So to ensure I get all records that are valid for a specific date range, the selection logic is: <...> WHERE end_date >= #dtFrom AND start_date < #dtTo (the #dtTo parameter used in the SQL statement is actually the calculated next day of the *#prmDt_To* parameter used in the report).
Now in a report I need to count the number of records for each day within the specified data range and include the days, if any, for which there were no valid records. Thus a retrieved record may be counted in several different days. I can do it relatively easily with a recursive CTE within the data set, but my rule of thumb is to avoid the unnecessary load on the SQL database and instead return just the necessary raw data and let the Report engine handle groupings. So is there a means to do this within SSRS?
Thank you,
Sergey
You might be able to do something in SSRS with custom code, but I recommend against it. The place to do this is in the dataset. SSRS is not designed to fill in groups that don't exist in the dataset. That sounds like what you are trying to do: SSRS would need to create the groups for each date whether or not that date is in the dataset.
If you don't have a number or date table in your database, I would just create a recursive CTE with a record for every date in the range that you are interested as you mention. Then outer join this to your table and use COUNT(tbl1.start_date) to find the appropriate days. This shouldn't be too painful a query for SQL server.
If you really need to avoid the CTE, then I would create a date or number table to use to generate the dates in your range.