Horton

Add SQL function CASEFOLD().

Jeff Davis <jdavis@postgresql.org>

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Commit: bfc5992069cf00b189af83d96a83ae5ebb65e938
Author: Jeff Davis <jdavis@postgresql.org>
Date: 2025-01-24T22:56:22Z
Releases: 18.0 
Add SQL function CASEFOLD().

Useful for caseless matching. Similar to LOWER(), but avoids edge-case
problems with using LOWER() for caseless matching.

For collations that support it, CASEFOLD() handles characters with
more than two case variations or multi-character case variations. Some
characters may fold to uppercase. The results of case folding are also
more stable across Unicode versions than LOWER() or UPPER().

Discussion: https://postgr.es/m/a1886ddfcd8f60cb3e905c93009b646b4cfb74c5.camel%40j-davis.com
Reviewed-by: Ian Lawrence Barwick

Files

PathChange+/−
doc/src/sgml/func.sgml modified +44 −2
src/backend/utils/adt/formatting.c modified +69 −0
src/backend/utils/adt/oracle_compat.c modified +16 −0
src/backend/utils/adt/pg_locale_builtin.c modified +10 −0
src/backend/utils/adt/pg_locale.c modified +24 −0
src/backend/utils/adt/pg_locale_icu.c modified +58 −0
src/include/catalog/catversion.h modified +1 −1
src/include/catalog/pg_proc.dat modified +3 −0
src/include/utils/formatting.h modified +1 −0
src/include/utils/pg_locale.h modified +3 −0
src/test/regress/expected/collate.icu.utf8.out modified +24 −0
src/test/regress/expected/collate.utf8.out modified +14 −0
src/test/regress/sql/collate.icu.utf8.sql modified +5 −0
src/test/regress/sql/collate.utf8.sql modified +6 −0

Documentation touched

Discussion