From 13822abd1b4919d9802525fda7e4b71d8f205f8c Mon Sep 17 00:00:00 2001
From: LucaCappelletti94 <cappelletti.luca94@gmail.com>
Date: Sun, 1 Mar 2026 17:44:46 +0100
Subject: [PATCH 1/2] parser(postgres): support RETURNS SETOF in CREATE
 FUNCTION

Add a dedicated SETOF data type wrapper in the AST, teach the PostgreSQL CREATE FUNCTION parser to wrap return types after RETURNS SETOF, and register SETOF in the keyword table so parsing no longer relies on raw NoKeyword text matching.
---
 src/ast/data_type.rs | 5 +++++
 src/keywords.rs      | 1 +
 src/parser/mod.rs    | 8 +++++++-
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/ast/data_type.rs b/src/ast/data_type.rs
index 285eec5054..51ed582ee4 100644
--- a/src/ast/data_type.rs
+++ b/src/ast/data_type.rs
@@ -47,6 +47,10 @@ pub enum EnumMember {
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum DataType {
+    /// Set-returning function type in [PostgreSQL], e.g. CREATE FUNCTION RETURNS SETOF UUID.
+    ///
+    /// [PostgreSQL]: https://www.postgresql.org/docs/current/sql-createfunction.html
+    SetOf(Box<DataType>),
     /// Table type in [PostgreSQL], e.g. CREATE FUNCTION RETURNS TABLE(...).
     ///
     /// [PostgreSQL]: https://www.postgresql.org/docs/15/sql-createfunction.html
@@ -501,6 +505,7 @@ pub enum DataType {
 impl fmt::Display for DataType {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
+            DataType::SetOf(data_type) => write!(f, "SETOF {data_type}"),
             DataType::Character(size) => format_character_string_type(f, "CHARACTER", size),
             DataType::Char(size) => format_character_string_type(f, "CHAR", size),
             DataType::CharacterVarying(size) => {
diff --git a/src/keywords.rs b/src/keywords.rs
index 80f679c07c..9f171cb247 100644
--- a/src/keywords.rs
+++ b/src/keywords.rs
@@ -933,6 +933,7 @@ define_keywords!(
     SESSION_USER,
     SET,
     SETERROR,
+    SETOF,
     SETS,
     SETTINGS,
     SHARE,
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 75450f75d0..89143478b9 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -5581,7 +5581,13 @@ impl<'a> Parser<'a> {
         self.expect_token(&Token::RParen)?;
 
         let return_type = if self.parse_keyword(Keyword::RETURNS) {
-            Some(self.parse_data_type()?)
+            let setof = self.parse_keyword(Keyword::SETOF);
+            let return_type = self.parse_data_type()?;
+            Some(if setof {
+                DataType::SetOf(Box::new(return_type))
+            } else {
+                return_type
+            })
         } else {
             None
         };

From cc4703c8a562ecacfa3d65c5e51ff81ce6ff1030 Mon Sep 17 00:00:00 2001
From: LucaCappelletti94 <cappelletti.luca94@gmail.com>
Date: Sun, 1 Mar 2026 17:45:00 +0100
Subject: [PATCH 2/2] tests(postgres): add CREATE FUNCTION RETURNS SETOF cases

Cover SETOF UUID function declarations for no-arg, parameterized, and array/unnest bodies, and assert return_type/language/behavior in the parsed AST.
---
 tests/sqlparser_postgres.rs | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/tests/sqlparser_postgres.rs b/tests/sqlparser_postgres.rs
index 434c5fd7b4..8d9930aa8a 100644
--- a/tests/sqlparser_postgres.rs
+++ b/tests/sqlparser_postgres.rs
@@ -4642,6 +4642,31 @@ fn parse_create_function_detailed() {
     );
 }
 
+#[test]
+fn parse_create_function_returns_setof() {
+    let cases = [
+        "CREATE FUNCTION any_ids() RETURNS SETOF UUID LANGUAGE sql STABLE AS 'SELECT ''00000000-0000-0000-0000-000000000000''::uuid'",
+        "CREATE FUNCTION ids_for_user(p_user_id UUID) RETURNS SETOF UUID LANGUAGE sql STABLE AS 'SELECT p_user_id'",
+        "CREATE FUNCTION ids_from_array() RETURNS SETOF UUID LANGUAGE sql STABLE AS 'SELECT unnest(ARRAY[''00000000-0000-0000-0000-000000000000''::uuid])'",
+    ];
+
+    for sql in cases {
+        match pg_and_generic().verified_stmt(sql) {
+            Statement::CreateFunction(CreateFunction {
+                return_type,
+                language,
+                behavior,
+                ..
+            }) => {
+                assert_eq!(return_type, Some(DataType::SetOf(Box::new(DataType::Uuid))));
+                assert_eq!(language, Some(Ident::new("sql")));
+                assert_eq!(behavior, Some(FunctionBehavior::Stable));
+            }
+            _ => panic!("Expected CreateFunction"),
+        }
+    }
+}
+
 #[test]
 fn parse_create_function_with_security() {
     let sql =