Improve PARTITION OF error handling and add tests.

- Add explicit check for FOR/DEFAULT after PARTITION OF with clear error message
- Document intentional removal of dialect check for multi-dialect tool support
- Add negative test cases for malformed PARTITION OF syntax

Author: fmguerreiro

src/parser/mod.rs

@@ -7834,6 +7834,9 @@ impl<'a> Parser<'a> {
         let table_name = self.parse_object_name(allow_unquoted_hyphen)?;
 
         // PostgreSQL PARTITION OF for child partition tables
+        // Note: This is a PostgreSQL-specific feature, but the dialect check was intentionally
+        // removed to allow GenericDialect and other dialects to parse this syntax. This enables
+        // multi-dialect SQL tools to work with PostgreSQL-specific DDL statements.
         let partition_of = if self.parse_keywords(&[Keyword::PARTITION, Keyword::OF]) {
             Some(self.parse_object_name(allow_unquoted_hyphen)?)
         } else {
@@ -7866,7 +7869,14 @@ impl<'a> Parser<'a> {
 
         // PostgreSQL PARTITION OF: partition bound specification
         let for_values = if partition_of.is_some() {
-            Some(self.parse_partition_for_values()?)
+            if self.peek_keyword(Keyword::FOR) || self.peek_keyword(Keyword::DEFAULT) {
+                Some(self.parse_partition_for_values()?)
+            } else {
+                return self.expected(
+                    "FOR VALUES or DEFAULT after PARTITION OF",
+                    self.peek_token(),
+                );
+            }
         } else {
             None
         };

tests/sqlparser_postgres.rs

@@ -7682,3 +7682,42 @@ CONSTRAINT check_date CHECK (order_date >= '2023-01-01')\
         _ => panic!("Expected CreateTable"),
     }
 }
+
+#[test]
+fn parse_create_table_partition_of_errors() {
+    let sql = "CREATE TABLE p PARTITION OF parent";
+    let result = pg_and_generic().parse_sql_statements(sql);
+    assert!(result.is_err());
+    let err = result.unwrap_err().to_string();
+    assert!(
+        err.contains("FOR VALUES or DEFAULT"),
+        "Expected error about FOR VALUES, got: {err}"
+    );
+
+    let sql = "CREATE TABLE p PARTITION OF parent WITH (fillfactor = 70)";
+    let result = pg_and_generic().parse_sql_statements(sql);
+    assert!(result.is_err());
+    let err = result.unwrap_err().to_string();
+    assert!(
+        err.contains("FOR VALUES or DEFAULT"),
+        "Expected error about FOR VALUES, got: {err}"
+    );
+
+    let sql = "CREATE TABLE p PARTITION OF parent FOR VALUES RANGE (1, 10)";
+    let result = pg_and_generic().parse_sql_statements(sql);
+    assert!(result.is_err());
+    let err = result.unwrap_err().to_string();
+    assert!(
+        err.contains("IN, FROM, or WITH"),
+        "Expected error about invalid keyword after FOR VALUES, got: {err}"
+    );
+
+    let sql = "CREATE TABLE p PARTITION OF parent FOR VALUES FROM (1)";
+    let result = pg_and_generic().parse_sql_statements(sql);
+    assert!(result.is_err());
+    let err = result.unwrap_err().to_string();
+    assert!(
+        err.contains("TO"),
+        "Expected error about missing TO clause, got: {err}"
+    );
+}