Custom Column Date Question

[tarisea]

I have a custom column (releasedate) with a date in it. The date is formatted dd mmm yy (13 Jan 13) and I want to leave this column alone.

I need another column that will look at this column and give me mmyy (0113). I have tried several ways but I keep getting the strangest results.

Can someone give me a hand.

Thanks you.

[chaley]

The template to use in the "column built from other columns" is

{#mydate:format_date(MMyy)}

with #mydate replaced with the lookup name of your column (#releasedate?).

Explanation: mm is minutes, 2 digits with a leading zero. MM is the month, again 2 digits with a leading zero.

[theducks]

http://manual.calibre-ebook.com/template_lang.html
in the section

format_date(x, date_format) – format_date(val, format_string) – format the value, which must be a date field, using the format_string, returning a string. The formatting codes are:

Old school DB guy here:

Why bloat the DB with 2 columns of the essentially the same data with a display variant?
If you need MMYY on an export, do it (the format conversion) in the save template
If you want the GUI to SHOW MMYY
Preferences: Add your own column: (select your column name):click the blue i and change the Format for dates (this is a Display format, not the data format, which is still a full date)

[tarisea]

Chaley that's perfect.

Just purely out of curiosity is it possible to take this one step further?

#column1 - numeric value
#column2 - fixed set of values, but only 1 is relevant here
#column3 - date

Is it possible to:

If #column1 >1 AND #column2=blue then {#column3:format_date(MMyy)} otherwise blank

Just pushing my luck. Tired of doing things manually.

Thanks

[chaley]

Originally Posted by tarisea

Chaley that's perfect.

Just purely out of curiosity is it possible to take this one step further?

#column1 - numeric value
#column2 - fixed set of values, but only 1 is relevant here
#column3 - date

Is it possible to:

If #column1 >1 AND #column2=blue then {#column3:format_date(MMyy)} otherwise blank

Just pushing my luck. Tired of doing things manually.

Thanks

program: cmp(
	field('#column1'), 
	1, 
	'', 
	'', 
	strcmp(
		field('#column2'), 
		'blue', 
		'',
		format_date(field('#column3'), 'MMyy'), 
		''
		))