Currently, I must manually do so, for each:
My Environment
Version: 25.8.4.2 (X86_64) Build ID: 580(Build:2) CPU threads: 12; OS: Linux 6.18; UI render: default; VCL: kf6 (cairo+wayland) Locale: en-GB (en_GB.UTF-8); UI: en-US Calc: threaded
Forms and reports constitute the user interface of your application, where dimensions are fixed. Forms and reports are made of tables and queries where formatting, column width and layout does not matter. Tables and queries show raw data without formatting.
@Villeroy, they evidently matter to me, because I’ve no desire for static, arbitrary widths, when those widths don’t encompass the names of the fields, and/or their data. I don’t see why automatic width isn’t the default.
So display them in Forms or Reports.
I don’t know of any DB where SELECTs are intended for displaying purposes to end users 
Sure: it could be. But not a necessary GUI’s feature.
@RokeJulianLockhart : Don’t know which version of LibreOffice you use, but here the automatic width is set by default. Note: Automatic width will only be the automatic width for the column header, not for the content. It will look like this:
Version: 26.2.0.1 (X86_64)
Build ID: 334ecff79a5ea28464a392deab1041cf2e705201
CPU threads: 6; OS: Linux 6.4; UI render: default; VCL: kf5 (cairo+xcb)
Locale: de-DE (de_DE.UTF-8); UI: en-US
Calc: threaded
@CRDF, I don’t see how debating what constitutes “a necessary GUI feature” is assistive.
@RobertG, you appear to be referring to libreoffice-calc-25.8.4.2-2.fc43 (although I’m unfamiliar with that modal), whereas I’m referring to libreoffice-25.8.4.2-2:
Name : libreoffice-base Epoch : 1 Version : 25.8.4.2 Release : 2.fc43 Architecture : x86_64 Download size : 2.3 MiB Installed size : 5.3 MiB Source : libreoffice-25.8.4.2-2.fc43.src.rpm Repository : updates Vendor : Fedora Project
@RokeJulianLockhart : Version I have tested with was LO-Version directly from LibreOffice, not from the packages of the Linux distribution I have installed. Go to Help → About to get the information on your installation. Seems to be Fedora, not original from LibreOffice. Base installed from original packages had set automatic column width - but it isn’t the same as you expect from Calc.
In Calc “automatic” will switch to the maximum width, which is needed.
In Base “automatic” will switch to the maximum, which is needed for the column header.