Adding custom column with any lookup-name gives me empty column as a result?

[Ahu Lee]

I'm trying to add a custom column, but no matter what I choose, it results in an empty column.

For example:

1. I go to Add your own columns dialog box
2. Create a custom column using the following. Lookup name: timestamp; Column heading: New Column; Column type: Date; Format for dates: yyyy)
3. Click Ok, Apply. Restart

Here I'm expecting to see a new column filled with four-digit numbers (the same ones I see in the original Date column, which also use timestamp lookup-name), but my new column is totally empty.

Why? Am I missing something here?

[BetterRed]

The attributes of Built-in Columns (the ones without an ionic column symbol) cannot be changed via Add your own Custom Columns.

There's a Tweak for date formats, viz:



BR

[Ahu Lee]

Originally Posted by BetterRed

The attributes of Built-in Columns (the ones without an ionic column symbol) cannot be changed via Add your own Custom Columns.

There's a Tweak for date formats, viz:

Attachment 171827

BR

Are you saying that I should have used the same date format as set in my tweak or what? Sorry, I'm not sure I understand you.

In my tweak the timestamp format is set as yyyy-MM-dd. In the Edit custom column dialog it says "Default: dd MMM yyyy" on the right side of the "Format for dates" field. I tried both. Nothing changed.

I can also, for example, use the authors variable/lookup-name with text column type and it will also be empty.

[BetterRed]

If you want the timestamp/Date column displayed as 'YYYY', you need to change the setting I posted before in Preferences->Advanced->Tweaks, viz:



You may have to scroll Preferences windows to get to Advanced. Search for 'date'

You can only add or change Custom columns in Preferences->Add your own columns - e.g. the ones in the red box, viz:



The built-in columns are in that list so you can a) include/exclude Book List columns and b) order the Book List columns.

BR

[Ahu Lee]

Originally Posted by BetterRed

If you want the timestamp/Date column displayed as 'YYYY', you need to change the setting I posted before in Preferences->Advanced->Tweaks, viz:

Attachment 171829

You may have to scroll Preferences windows to get to Advanced. Search for 'date'

You can only add or change Custom columns in Preferences->Add your own columns - e.g. the ones in the red box, viz:

Attachment 171830

The built-in columns are in that list so you can a) include/exclude Book List columns and b) order the Book List columns.

BR

Please don't be so fixated on this date thing. I never said anywhere that I want my date column to be displayed in this or that way. My question is not about date at all. I used it as an example, okay.

I also understand what the word 'custom' means. And I'm not trying to change any column which is not custom.

So, now once the above is established I can only try to repeat/rephrase what my problem/confusion is about.

There are different default lookup-names in Calibre (title, size, timestamp, authors etc.). I think of them as variables of sort. Am I right about it or wrong? And since I think of them as kind of variables I expect that they can be called. Am I right about it or wrong? So, I expected I could use those lookup names/variables in my custom column, but apparently it's not so, because all I got were empty columns. So, non-working (as I expect them to) lookup-names is my issue. That's what I don't understand and that's where I need help.

[kovidgoyal]

If you wan tto create a column that shows data from other columns it has to be of type "Column built from other clumns" and you have to specify a template for it. https://manual.calibre-ebook.com/template_lang.html

[Ahu Lee]

Originally Posted by kovidgoyal

If you wan tto create a column that shows data from other columns it has to be of type "Column built from other clumns" and you have to specify a template for it. https://manual.calibre-ebook.com/template_lang.html

Great. Thank you, I'll look into it. But what do I do if the lookup name I want to use is not related to any other columns data. For example, I'm particularly interested in "author_sort" (I've found it on "Title/author/series" tab of "Advanced search dialog"). Should I still use "Column built from other columns" in this case?

[Sunlite]

Custom columns are mainlya way for you to store information for your books not fitting the standard columns. When they are created, they are empty. You can then fill them with your info.

"Column built from other columns" is a way to combine existing informations and make it available in searches and templates.
Too many columns of this kind can slow down your library, because the information is always calculated on the fly.


To use author_sort you do not need a custom column, that is already a lookup name

Edit: Maybe you could tell us what goal you want to reach? There might be a way there, you are not seeing right now.

[DNSB]

Originally Posted by Ahu Lee

There are different default lookup-names in Calibre (title, size, timestamp, authors etc.). I think of them as variables of sort. Am I right about it or wrong? And since I think of them as kind of variables I expect that they can be called. Am I right about it or wrong? So, I expected I could use those lookup names/variables in my custom column, but apparently it's not so, because all I got were empty columns. So, non-working (as I expect them to) lookup-names is my issue. That's what I don't understand and that's where I need help.

Unless you use one of the two column built from other columns functionality, how is your new column going to get any information? I have a column called Additional Authors and it remains empty until I populate it manually--that column is used mostly for multi-author collections of short stories.

[Ahu Lee]

Originally Posted by Sunlite

Custom columns are mainlya way for you to store information for your books not fitting the standard columns. When they are created, they are empty. You can then fill them with your info.

"Column built from other columns" is a way to combine existing informations and make it available in searches and templates.
Too many columns of this kind can slow down your library, because the information is always calculated on the fly.


To use author_sort you do not need a custom column, that is already a lookup name

Edit: Maybe you could tell us what goal you want to reach? There might be a way there, you are not seeing right now.

Thank you. My goal is/was to create a custom column where I could use "Author sort" field as author's name. For that I wanted to use "author_sort" lookup name, similar to how Author(s) column "uses" "authors" one. But, now I see that's not possible, because these lookup-names are defensively not what I initially thought them to be.

Just to clarify. So, is it true that there's no way for me to have a column in Calibre which would use "Author sort" field instead of "Author(s)" one? Or it can be done applying some Python magic somewhere at least?

[Ahu Lee]

Originally Posted by DNSB

Unless you use one of the two column built from other columns functionality, how is your new column going to get any information? I have a column called Additional Authors and it remains empty until I populate it manually--that column is used mostly for multi-author collections of short stories.

I initially thought that columns could get information from .opf files. For example, information I'm interested in is under "opf:file-as" attribute of the <dc:creator> tag. The program should be able to reach it. And it obviously does so, otherwise it wouldn't be there and the "Author sort field" in "Edit Metadata" would be always empty.

[Sunlite]

Originally Posted by Ahu Lee

Just to clarify. So, is it true that there's no way for me to have a column in Calibre which would use "Author sort" field instead of "Author(s)" one? Or it can be done applying some Python magic somewhere at least?

No, that is not true!

You can creat a custom column with "Column built from other columns" from type "Text" with the template {author_sort}.
After a restart of Calibre this column will display the value of author_sort.

[Ahu Lee]

Originally Posted by Sunlite

No, that is not true!

You can creat a custom column with "Column built from other columns" from type "Text" with the template {author_sort}.
After a restart of Calibre this column will display the value of author_sort.

That did what I wanted! But I should say this was absolutely counterintuitive to me. "Column built from other columns" could be called "The quick brown fox jumps over the lazy dog" and it would make as much sense to me.

[Bookstooge]

Originally Posted by Ahu Lee

That did what I wanted! But I should say this was absolutely counterintuitive to me. "Column built from other columns" could be called "The quick brown fox jumps over the lazy dog" and it would make as much sense to me.

Well, now you are a wiser and better person for having learned something!

[theducks]

Originally Posted by Ahu Lee

That did what I wanted! But I should say this was absolutely counterintuitive to me. "Column built from other columns" could be called "The quick brown fox jumps over the lazy dog" and it would make as much sense to me.

While it said 'from other', it did not mandate that you must use more than one (which is what a lot of people mostly do).

As others have pointed out: table (more columns and those 'built') bloat, slow things down. The bigger the Library, the more important this becomes.
FWIW

author_sort:jones

is a valid Search term, even though you can't see the column. And sorting on the Authors column (as shipped settings) really uses {author_sort}, but you Still SEE the authors first name, but in the proper order
Anne Lee Jones
Mary Jones
Wilbur Jones
(or
Jones, Anne Lee
Jones, Mary
Jones, Wilbur
)