hi.
CREATE COLLATION case_insensitive (provider = icu, locale =
'@colStrength=secondary', deterministic = false);
SELECT 'a' = 'A' COLLATE case_insensitive;
CREATE DOMAIN d1 as text collate case_insensitive check (value <> 'a');
SELECT 'A'::d1;
``SELECT 'A'::d1`` should error out as domain check constraint not satisfied?
If so, attached is the POC trying to implement it.
From 8d0b94976c5c1c0cf16f70f7d740ea4f37698340 Mon Sep 17 00:00:00 2001
From: jian he <jian.universal...@gmail.com>
Date: Mon, 14 Jul 2025 16:14:32 +0800
Subject: [PATCH v1 1/1] CoerceToDomainValue should use domain's collation
---
src/backend/commands/typecmds.c | 15 ++++++++-----
.../regress/expected/collate.icu.utf8.out | 21 +++++++++++++++++++
src/test/regress/sql/collate.icu.utf8.sql | 10 +++++++++
3 files changed, 41 insertions(+), 5 deletions(-)
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 26d985193ae..529001d7bfc 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -133,7 +133,8 @@ static void checkEnumOwner(HeapTuple tup);
static char *domainAddCheckConstraint(Oid domainOid, Oid domainNamespace,
Oid baseTypeOid,
int typMod, Constraint *constr,
- const char *domainName, ObjectAddress *constrAddr);
+ const char *domainName, Oid domaincoll,
+ ObjectAddress *constrAddr);
static Node *replace_domain_constraint_value(ParseState *pstate,
ColumnRef *cref);
static void domainAddNotNullConstraint(Oid domainOid, Oid domainNamespace, Oid baseTypeOid,
@@ -1145,7 +1146,7 @@ DefineDomain(ParseState *pstate, CreateDomainStmt *stmt)
case CONSTR_CHECK:
domainAddCheckConstraint(address.objectId, domainNamespace,
basetypeoid, basetypeMod,
- constr, domainName, NULL);
+ constr, domainName, domaincoll, NULL);
break;
case CONSTR_NOTNULL:
@@ -2937,6 +2938,7 @@ AlterDomainAddConstraint(List *names, Node *newConstraint,
{
TypeName *typename;
Oid domainoid;
+ Oid domaincoll;
Relation typrel;
HeapTuple tup;
Form_pg_type typTup;
@@ -2948,6 +2950,8 @@ AlterDomainAddConstraint(List *names, Node *newConstraint,
typename = makeTypeNameFromNameList(names);
domainoid = typenameTypeId(NULL, typename);
+ domaincoll = get_typcollation(domainoid);
+
/* Look up the domain in the type table */
typrel = table_open(TypeRelationId, RowExclusiveLock);
@@ -2977,7 +2981,7 @@ AlterDomainAddConstraint(List *names, Node *newConstraint,
ccbin = domainAddCheckConstraint(domainoid, typTup->typnamespace,
typTup->typbasetype, typTup->typtypmod,
- constr, NameStr(typTup->typname), constrAddr);
+ constr, NameStr(typTup->typname), domaincoll, constrAddr);
/*
@@ -3504,7 +3508,8 @@ checkDomainOwner(HeapTuple tup)
static char *
domainAddCheckConstraint(Oid domainOid, Oid domainNamespace, Oid baseTypeOid,
int typMod, Constraint *constr,
- const char *domainName, ObjectAddress *constrAddr)
+ const char *domainName, Oid domaincoll,
+ ObjectAddress *constrAddr)
{
Node *expr;
char *ccbin;
@@ -3549,7 +3554,7 @@ domainAddCheckConstraint(Oid domainOid, Oid domainNamespace, Oid baseTypeOid,
domVal = makeNode(CoerceToDomainValue);
domVal->typeId = baseTypeOid;
domVal->typeMod = typMod;
- domVal->collation = get_typcollation(baseTypeOid);
+ domVal->collation = domaincoll;
domVal->location = -1; /* will be set when/if used */
pstate->p_pre_columnref_hook = replace_domain_constraint_value;
diff --git a/src/test/regress/expected/collate.icu.utf8.out b/src/test/regress/expected/collate.icu.utf8.out
index 69805d4b9ec..002e61c1e0e 100644
--- a/src/test/regress/expected/collate.icu.utf8.out
+++ b/src/test/regress/expected/collate.icu.utf8.out
@@ -1459,6 +1459,27 @@ CREATE COLLATION case_sensitive (provider = icu, locale = '');
NOTICE: using standard form "und" for ICU locale ""
CREATE COLLATION case_insensitive (provider = icu, locale = '@colStrength=secondary', deterministic = false);
NOTICE: using standard form "und-u-ks-level2" for ICU locale "@colStrength=secondary"
+--domain with check constraints
+CREATE DOMAIN d0 as text COLLATE "C" check (value <> 'a');
+CREATE DOMAIN d1 as d0 COLLATE case_insensitive check (value <> 'b');
+CREATE DOMAIN d2 as d0 COLLATE case_insensitive;
+SELECT 'A'::d1; --ok
+ d1
+----
+ A
+(1 row)
+
+SELECT 'a'::d1; --error
+ERROR: value for domain d1 violates check constraint "d0_check"
+SELECT 'B'::d1; --error
+ERROR: value for domain d1 violates check constraint "d1_check"
+SELECT 'A'::d2; --ok
+ d2
+----
+ A
+(1 row)
+
+DROP DOMAIN d0, d1, d2;
SELECT 'abc' <= 'ABC' COLLATE case_sensitive, 'abc' >= 'ABC' COLLATE case_sensitive;
?column? | ?column?
----------+----------
diff --git a/src/test/regress/sql/collate.icu.utf8.sql b/src/test/regress/sql/collate.icu.utf8.sql
index dbc190227d0..d50f75fb819 100644
--- a/src/test/regress/sql/collate.icu.utf8.sql
+++ b/src/test/regress/sql/collate.icu.utf8.sql
@@ -561,6 +561,16 @@ SELECT * FROM test6a WHERE b = ARRAY['äbc'] COLLATE ctest_nondet;
CREATE COLLATION case_sensitive (provider = icu, locale = '');
CREATE COLLATION case_insensitive (provider = icu, locale = '@colStrength=secondary', deterministic = false);
+--domain with check constraints
+CREATE DOMAIN d0 as text COLLATE "C" check (value <> 'a');
+CREATE DOMAIN d1 as d0 COLLATE case_insensitive check (value <> 'b');
+CREATE DOMAIN d2 as d0 COLLATE case_insensitive;
+SELECT 'A'::d1; --ok
+SELECT 'a'::d1; --error
+SELECT 'B'::d1; --error
+SELECT 'A'::d2; --ok
+DROP DOMAIN d0, d1, d2;
+
SELECT 'abc' <= 'ABC' COLLATE case_sensitive, 'abc' >= 'ABC' COLLATE case_sensitive;
SELECT 'abc' <= 'ABC' COLLATE case_insensitive, 'abc' >= 'ABC' COLLATE case_insensitive;
--
2.34.1
