PostgreSQL: Support COLLATION members in ALTER EXTENSION

fuzz/fuzz_seeds/postgres_alter_extension.sql

@@ -12,3 +12,4 @@ ALTER EXTENSION citext ADD ACCESS METHOD btree;
 ALTER EXTENSION citext DROP EVENT TRIGGER trg;
 ALTER EXTENSION citext ADD FOREIGN DATA WRAPPER fdw;
 ALTER EXTENSION citext DROP SERVER srv;
+ALTER EXTENSION citext ADD COLLATION public.coll;

src/ast/ddl.rs

@@ -4928,6 +4928,8 @@ pub enum AlterExtensionOperation {
 pub enum AlterExtensionMember {
     /// `ACCESS METHOD object_name`
     AccessMethod(Ident),
+    /// `COLLATION object_name`
+    Collation(ObjectName),
     /// `EVENT TRIGGER object_name`
     EventTrigger(Ident),
     /// `FOREIGN DATA WRAPPER object_name`
@@ -4978,6 +4980,7 @@ impl fmt::Display for AlterExtensionMember {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
             AlterExtensionMember::AccessMethod(name) => write!(f, "ACCESS METHOD {name}"),
+            AlterExtensionMember::Collation(name) => write!(f, "COLLATION {name}"),
             AlterExtensionMember::EventTrigger(name) => write!(f, "EVENT TRIGGER {name}"),
             AlterExtensionMember::ForeignDataWrapper(name) => {
                 write!(f, "FOREIGN DATA WRAPPER {name}")

src/parser/mod.rs

@@ -12541,6 +12541,10 @@ impl<'a> Parser<'a> {
     fn parse_alter_extension_member(&mut self) -> Result<AlterExtensionMember, ParserError> {
         if self.parse_keywords(&[Keyword::ACCESS, Keyword::METHOD]) {
             Ok(AlterExtensionMember::AccessMethod(self.parse_identifier()?))
+        } else if self.parse_keyword(Keyword::COLLATION) {
+            Ok(AlterExtensionMember::Collation(
+                self.parse_object_name(false)?,
+            ))
         } else if self.parse_keywords(&[Keyword::EVENT, Keyword::TRIGGER]) {
             Ok(AlterExtensionMember::EventTrigger(self.parse_identifier()?))
         } else if self.parse_keywords(&[Keyword::FOREIGN, Keyword::DATA, Keyword::WRAPPER]) {

tests/sqlparser_postgres.rs

@@ -13529,6 +13529,8 @@ fn parse_case_ending_in_end_keyword_is_not_silently_dropped() {
 fn alter_extension_member_round_trip_forms(action: &str) {
     let sqls = [
         format!("ALTER EXTENSION ext_name {action} ACCESS METHOD btree"),
+        format!("ALTER EXTENSION ext_name {action} COLLATION en_US"),
+        format!("ALTER EXTENSION ext_name {action} COLLATION schema.en_US"),
         format!("ALTER EXTENSION ext_name {action} EVENT TRIGGER trg"),
         format!("ALTER EXTENSION ext_name {action} FOREIGN DATA WRAPPER fdw"),
         format!("ALTER EXTENSION ext_name {action} FOREIGN TABLE ft"),
@@ -13718,6 +13720,7 @@ fn parse_alter_extension_add_member() {
 
     for member in [
         "ACCESS METHOD",
+        "COLLATION",
         "EVENT TRIGGER",
         "FOREIGN DATA WRAPPER",
         "FOREIGN TABLE",