From 7b2e06b69a61fa357837b53b5cd8399b4f8110d5 Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Sun, 27 Sep 2026 00:14:16 -0700
Subject: [PATCH] Parse and ignore NULLS FIRST / NULLS LAST in index columns

Postgres supports NULLS FIRST / NULLS LAST in the column specification
of an index. Parse it and ignore it.
---
 qusql-parse/src/alter_table.rs  |  4 ++++
 qusql-parse/src/create_index.rs | 15 +++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/qusql-parse/src/alter_table.rs b/qusql-parse/src/alter_table.rs
index e86e901b..08c63982 100644
--- a/qusql-parse/src/alter_table.rs
+++ b/qusql-parse/src/alter_table.rs
@@ -189,6 +189,8 @@ pub struct IndexCol<'a> {
     pub asc: Option<Span>,
     /// Optional DESC ordering
     pub desc: Option<Span>,
+    /// Optional NULLS FIRST / NULLS LAST ordering; bool is `true` if FIRST
+    pub nulls_first_last: Option<(bool, Span)>,
 }
 
 impl<'a> Spanned for IndexCol<'a> {
@@ -198,6 +200,7 @@ impl<'a> Spanned for IndexCol<'a> {
             .join_span(&self.opclass)
             .join_span(&self.asc)
             .join_span(&self.desc)
+            .join_span(&self.nulls_first_last)
     }
 }
 
@@ -1709,6 +1712,7 @@ pub(crate) fn parse_index_cols<'a>(
                 opclass,
                 asc,
                 desc,
+                nulls_first_last: None,
             });
             if parser.skip_token(Token::Comma).is_none() {
                 break;
diff --git a/qusql-parse/src/create_index.rs b/qusql-parse/src/create_index.rs
index 80877215..682c8a1b 100644
--- a/qusql-parse/src/create_index.rs
+++ b/qusql-parse/src/create_index.rs
@@ -270,12 +270,27 @@ pub(crate) fn parse_create_index<'a>(
             None
         };
 
+        // Parse optional NULLS FIRST | NULLS LAST
+        let nulls_first_last = if let Some(nulls_span) = parser.skip_keyword(Keyword::NULLS) {
+            if let Some(first_span) = parser.skip_keyword(Keyword::FIRST) {
+                Some((true, nulls_span.join_span(&first_span)))
+            } else if let Some(last_span) = parser.skip_keyword(Keyword::LAST) {
+                Some((false, nulls_span.join_span(&last_span)))
+            } else {
+                return parser.err_here("Expected FIRST or LAST after NULLS");
+            }
+        } else {
+            None
+        };
+        parser.postgres_only(&nulls_first_last);
+
         column_names.push(IndexCol {
             expr,
             size,
             opclass,
             asc,
             desc,
+            nulls_first_last,
         });
 
         if parser.skip_token(Token::Comma).is_none() {