Oracle Apex 4.2图表因问题悬停

Question

I have build a chart for one of the departments:

select 'f?p=&APP_ID.:802:'||:app_session||'::::P802_ENQ_DATE:'|| e.enq_date ||':'  link, 
cal_date as label,
 value1 as value 
from 
(select cal_date from time
where cal_date >= '01-'||:P802_SEARCH_MONTH and
cal_date <= last_day(to_date('01-'||:P802_SEARCH_MONTH, 'dd-mm-yy')) 

 ) t

LEFT OUTER JOIN

(SELECT
a.enquired_date AS enq_date,
COUNT(a.id) AS value1
FROM
ENQUIRY a 
group by a.enquired_date
) e 
ON
to_char(e.enq_date) = to_char(t.cal_date)
order by label ASC

The requirement was to present number of daily enquiries in selected by end user month.So :P802_SEARCH_MONTH captures name of the month and pass this parameter to time table. Time table stores all possible date days, then chart adds up all enquiries per day and throw joins them with dates. It is important to show all possible dates as in some days there was not any enquiries and if it would be the other way round it would not display full date range.

Anyhow, when you hoover over the bar of the chart it shows 'label'

I have requirement to include name of the day into the label.I tried extending 't' statement:

    select 'f?p=&APP_ID.:802:'||:app_session||'::::P802_ENQ_DATE:'|| e.enq_date ||':'  link, 
full_date as label,
 value1 as value 
from 
    (select to_char(to_date(cal_date,'dd-mon-yy'), 'DAY')||' - '|| cal_Date as full_date from time
    where cal_date >= '01-'||:P802_SEARCH_MONTH and
    cal_date <= last_day(to_date('01-'||:P802_SEARCH_MONTH, 'dd-mm-yy')) 

     ) t

this does not work. Apex is not throwing any meaningful errors. Any help greatly appreciated.

Answer 1

Don't change your source query, t . Is cal_date a DATE column? (i presume it is indeed a date column)

to_char(to_date(cal_date,'dd-mon-yy'), 'DAY')

If it is then you cast a date to a date and then apply a format mask. Don't cast dates to dates. It already is a date.
Be careful with date conversion aswell. In apex you should always work with explicit format masks and not rely on implicit conversion - this will come back and haunt you some day otherwise.

You need to alter the LABEL column

cal_date as label,

This will be the tooltip value. Right now you are returning a DATE and that is what you see when you hover over the datapoint. The database's format mask is simply applied to it.
If you want to change it then you can just apply a format mask to the date and show that in the tooltip.

select 'f?p=...' AS link, 
       TO_CHAR(cal_date, 'DAY') || ' - ' || cal_date AS label,
       value1 AS value 
from ...