From cca174c40c25714cda4c6b32379bf88ca2670b65 Mon Sep 17 00:00:00 2001
From: Ben Herzberg <ben@satoricyber.com>
Date: Thu, 10 Sep 2026 17:53:34 +0300
Subject: [PATCH] Postgres: Support aliases for JOIN USING

---
 src/ast/query.rs            | 5 +++++
 src/ast/spans.rs            | 6 ++++++
 src/parser/mod.rs           | 9 ++++++++-
 tests/sqlparser_postgres.rs | 8 ++++++++
 4 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/ast/query.rs b/src/ast/query.rs
index 296e4e8ca6..ebb8f49986 100644
--- a/src/ast/query.rs
+++ b/src/ast/query.rs
@@ -2701,6 +2701,9 @@ impl fmt::Display for Join {
                         JoinConstraint::Using(attrs) => {
                             write!(f, " USING({})", display_comma_separated(attrs))
                         }
+                        JoinConstraint::UsingAlias(columns, alias) => {
+                            write!(f, " USING({}) AS {alias}", display_comma_separated(columns))
+                        }
                         _ => Ok(()),
                     }
                 }
@@ -2890,6 +2893,8 @@ pub enum JoinConstraint {
     On(Expr),
     /// `USING(...)` list of column names.
     Using(Vec<ObjectName>),
+    /// `USING(...) AS alias` list of column names with an alias for the joined columns.
+    UsingAlias(Vec<ObjectName>, Ident),
     /// `NATURAL` join (columns matched automatically).
     Natural,
     /// No constraint specified (e.g. `CROSS JOIN`).
diff --git a/src/ast/spans.rs b/src/ast/spans.rs
index cb06b78990..e947652938 100644
--- a/src/ast/spans.rs
+++ b/src/ast/spans.rs
@@ -2304,6 +2304,12 @@ impl Spanned for JoinConstraint {
         match self {
             JoinConstraint::On(expr) => expr.span(),
             JoinConstraint::Using(vec) => union_spans(vec.iter().map(|i| i.span())),
+            JoinConstraint::UsingAlias(columns, alias) => union_spans(
+                columns
+                    .iter()
+                    .map(|i| i.span())
+                    .chain(iter::once(alias.span)),
+            ),
             JoinConstraint::Natural => Span::empty(),
             JoinConstraint::None => Span::empty(),
         }
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 2171548f91..1d06b9db3a 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -17738,7 +17738,14 @@ impl<'a> Parser<'a> {
             Ok(JoinConstraint::On(constraint))
         } else if self.parse_keyword(Keyword::USING) {
             let columns = self.parse_parenthesized_qualified_column_list(Mandatory, false)?;
-            Ok(JoinConstraint::Using(columns))
+            if self.parse_keyword(Keyword::AS) {
+                Ok(JoinConstraint::UsingAlias(
+                    columns,
+                    self.parse_identifier()?,
+                ))
+            } else {
+                Ok(JoinConstraint::Using(columns))
+            }
         } else {
             Ok(JoinConstraint::None)
             //self.expected_ref("ON, or USING after JOIN", self.peek_token_ref())
diff --git a/tests/sqlparser_postgres.rs b/tests/sqlparser_postgres.rs
index dfd883eb4d..9df57ae3b9 100644
--- a/tests/sqlparser_postgres.rs
+++ b/tests/sqlparser_postgres.rs
@@ -9918,3 +9918,11 @@ fn parse_non_reserved_keywords_as_table_alias() {
         ));
     }
 }
+
+#[test]
+fn parse_join_using_alias() {
+    pg().one_statement_parses_to(
+        "SELECT * FROM t1 JOIN t2 USING (id) AS joined_cols",
+        "SELECT * FROM t1 JOIN t2 USING(id) AS joined_cols",
+    );
+}