fix: parse INSERT BY NAME permissively

Author: finchxxia

src/dialect/databricks.rs

@@ -95,10 +95,6 @@ impl Dialect for DatabricksDialect {
         true
     }
 
-    fn supports_insert_by_name(&self) -> bool {
-        true
-    }
-
     /// See <https://docs.databricks.com/aws/en/sql/language-manual/functions/bangsign>
     fn supports_bang_not_operator(&self) -> bool {
         true

src/dialect/generic.rs

@@ -320,8 +320,4 @@ impl Dialect for GenericDialect {
     fn supports_aliased_function_args(&self) -> bool {
         true
     }
-
-    fn supports_insert_by_name(&self) -> bool {
-        true
-    }
 }

src/dialect/mod.rs

@@ -1353,13 +1353,6 @@ pub trait Dialect: Debug + Any {
         false
     }
 
-    /// Returns true if this dialect supports `INSERT INTO ... BY NAME ...`.
-    ///
-    /// Databricks: <https://docs.databricks.com/aws/en/sql/language-manual/sql-ref-syntax-dml-insert-into>
-    fn supports_insert_by_name(&self) -> bool {
-        false
-    }
-
     /// Returns true if this dialect supports `SET` statements without an explicit
     /// assignment operator such as `=`. For example: `SET SHOWPLAN_XML ON`.
     fn supports_set_stmt_without_operator(&self) -> bool {

src/parser/mod.rs

@@ -18314,7 +18314,9 @@ impl<'a> Parser<'a> {
             let table = self.parse_keyword(Keyword::TABLE);
             let table_object = self.parse_table_object()?;
 
+            // `BY NAME` is an INSERT clause, not a table alias.
             let table_alias = if self.dialect.supports_insert_table_alias()
+                && !self.peek_keywords(&[Keyword::BY, Keyword::NAME])
                 && !self.peek_sub_query()
                 && self
                     .peek_one_of_keywords(&[Keyword::DEFAULT, Keyword::VALUES])
@@ -18349,9 +18351,7 @@ impl<'a> Parser<'a> {
                         self.parse_parenthesized_qualified_column_list(Optional, is_mysql)?;
 
                     let partitioned = self.parse_insert_partition()?;
-                    by_name = columns.is_empty()
-                        && self.dialect.supports_insert_by_name()
-                        && self.parse_keywords(&[Keyword::BY, Keyword::NAME]);
+                    by_name = self.parse_keywords(&[Keyword::BY, Keyword::NAME]);
                     // Hive allows you to specify columns after partitions as well if you want.
                     let after_columns = if dialect_of!(self is HiveDialect) {
                         self.parse_parenthesized_column_list(Optional, false)?

tests/sqlparser_common.rs

@@ -19584,3 +19584,18 @@ fn parse_function_arg_call_chain_no_exponential_blowup() {
     rx.recv_timeout(Duration::from_secs(5))
         .expect("parser should reject this quickly, not loop exponentially");
 }
+
+#[test]
+fn parse_insert_by_name_in_all_dialects() {
+    verified_stmt("INSERT INTO target BY NAME SELECT 1 AS a");
+
+    match verified_stmt("INSERT INTO target (a) BY NAME SELECT 1 AS a") {
+        Statement::Insert(Insert {
+            by_name, columns, ..
+        }) => {
+            assert!(by_name);
+            assert_eq!(columns.len(), 1);
+        }
+        _ => unreachable!(),
+    }
+}