0. emacs -Q
1. C-u M-x sql-product-interactive RET

Now the minbuffer displays the following:

SQL product: ansi

so it you want to change the product, e.g. to postgres, you first have
to delete "ansi".

Likewise, `M-x sql-set-product RET' produces the same minbuffer display,
requiring deletion to change the product.

The reason "ansi" is displayed after the prompt is that the definition
of sql-read-product uses the same non-nil value of the deprecated
argument INITIAL-INPUT as is used for the argument DEF.  The attached
patch makes INITIAL-INPUT nil, thus using only DEF, and also wraps the
prompt argument of sql-read-product in format-prompt, so the default
value is shown as part of the prompt and changing it does not require
deletion.  The patch also adjusts the two callers of sql-read-product
accordingly.


In GNU Emacs 31.0.50 (build 3, x86_64-pc-linux-gnu, GTK+ Version
 3.24.43, cairo version 1.18.2) of 2024-09-12 built on strobelfssd
Repository revision: 31e8500b061b6963708e66468fc89db1006226d7
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101013
System Description: Linux From Scratch r12.2-5-systemd

Configured using:
 'configure -C 'CFLAGS=-Og -g3''

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
LCMS2 LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG
RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER
WEBP X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB