database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-08-08 11:22:35 +03:00
Code Activity

MDEV-30164 System variable for default collations

Browse Source 
This patch adds a way to override default collations
(or "character set collations") for desired character sets.

The SQL standard says:
> Each collation known in an SQL-environment is applicable to one
> or more character sets, and for each character set, one or more
> collations are applicable to it, one of which is associated with
> it as its character set collation.

In MariaDB, character set collations has been hard-coded so far,
e.g. utf8mb4_general_ci has been a hard-coded character set collation
for utf8mb4.

This patch allows to override (globally per server, or per session)
character set collations, so for example, uca1400_ai_ci can be set as a
character set collation for Unicode character sets
(instead of compiled xxx_general_ci).

The array of overridden character set collations is stored in a new
(session and global) system variable @@character_set_collations and
can be set as a comma separated list of charset=collation pairs, e.g.:

SET @@character_set_collations='utf8mb3=uca1400_ai_ci,utf8mb4=uca1400_ai_ci';

The variable is empty by default, which mean use the hard-coded
character set collations (e.g. utf8mb4_general_ci for utf8mb4).

The variable can also be set globally by passing to the server startup command
line, and/or in my.cnf.
This commit is contained in:
Alexander Barkov
2022-12-14 18:46:27 +04:00
parent 584c2351de
commit 75f25e4ca7
59 changed files with 2228 additions and 111 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
sql/json_table.cc
View File

@@ -925,7 +925,10 @@ int Json_table_column::set(THD *thd, enum_type ctype, const LEX_CSTRING &path,
return set(thd, ctype, path, nullptr);
CHARSET_INFO *tmp;
if (!(tmp= cl.resolved_to_character_set(&my_charset_utf8mb4_general_ci)))
if (!(tmp= cl.resolved_to_character_set(
thd,
thd->variables.character_set_collations,
&my_charset_utf8mb4_general_ci)))
return 1;
return set(thd, ctype, path, tmp);
}