[chaley]

Originally Posted by Silek

When I run calibredb set_metadata on the OPF file I generate, I do not get an error, but I also do not get the user columns set.

Command line set_metadata will update custom columns.

The format for custom columns in the OPF is complicated. My guess is that you have it wrong and the data is being ignored. Change a book using the GUI to have the data you expect when you run set_metadata, then look at the metadata.opf file for the book. Ensure that your script generates exactly the same stuff.

What is strange to me also is when I add fields to the user columns in the GUI, then run show_metadata, I do not see the entries in the OPF file for the user column.

I see them in both the OPF and columnar output. For example, dumping the OPF for one of my books in my test library I get

Spoiler:

<meta name="calibre:user_metadata:#enum" content="{&quot;
is_category&quot;: true, &quot;
#extra#&quot;: null, &quot;
kind&quot;: &quot;
field&quot;, &quot;
is_custom&quot;: true, &quot;
is_csp&quot;: false, &quot;
colnum&quot;: 7, &quot;
column&quot;: &quot;value&quot;, &quot;
rec_index&quot;: 28, &quot;
search_terms&quot;: [&quot;#enum&quot;], &quot;
link_column&quot;: &quot;value&quot;, &quot;
is_multiple2&quot;: {}, &quot;
is_multiple&quot;: null, &quot;
datatype&quot;: &quot;enumeration&quot;, &quot;
#value#&quot;: &quot;def&quot;, &quot;
category_sort&quot;: &quot;value&quot;, &quot;
table&quot;: &quot;custom_column_7&quot;, &quot;
is_editable&quot;: true, &quot;
label&quot;: &quot;enum&quot;, &quot;
display&quot;: {&quot;use_decorations&quot;: 2, &quot;enum_values&quot;: [&quot;def&quot;, &quot;one&quot;, &quot;two&quot;, &quot;five&
quot;, &quot;no&quot;]}, &quot;
name&quot;: &quot;énum&quot;
}"/>

However, during testing I did find a bug in the OPF renderer that has been there for over a year (!). The generated OPF has empty values for tags-like custom columns. If you are testing exclusively with an is_multiple datatype, that would explain you not seeing. Non-multiple columns do render values correctly, as shown above. Note that the columnar output does not suffer from this problem.