Fixing ALTER EXTERNAL TABLE queries for snowflake

src/ast/ddl.rs

@@ -3880,8 +3880,11 @@ pub enum AlterTableType {
     /// <https://docs.snowflake.com/en/sql-reference/sql/alter-iceberg-table>
     Iceberg,
     /// Dynamic table type
-    /// <https://docs.snowflake.com/en/sql-reference/sql/alter-table>
+    /// <https://docs.snowflake.com/en/sql-reference/sql/alter-dynamic-table>
     Dynamic,
+    /// External table type
+    /// <https://docs.snowflake.com/en/sql-reference/sql/alter-external-table>
+    External,
 }
 
 /// ALTER TABLE statement
@@ -3911,6 +3914,7 @@ impl fmt::Display for AlterTable {
         match &self.table_type {
             Some(AlterTableType::Iceberg) => write!(f, "ALTER ICEBERG TABLE ")?,
             Some(AlterTableType::Dynamic) => write!(f, "ALTER DYNAMIC TABLE ")?,
+            Some(AlterTableType::External) => write!(f, "ALTER EXTERNAL TABLE ")?,
             None => write!(f, "ALTER TABLE ")?,
         }
 

src/dialect/snowflake.rs

@@ -221,6 +221,11 @@ impl Dialect for SnowflakeDialect {
             return Some(parse_alter_dynamic_table(parser));
         }
 
+        if parser.parse_keywords(&[Keyword::ALTER, Keyword::EXTERNAL, Keyword::TABLE]) {
+            // ALTER EXTERNAL TABLE
+            return Some(parse_alter_external_table(parser));
+        }
+
         if parser.parse_keywords(&[Keyword::ALTER, Keyword::SESSION]) {
             // ALTER SESSION
             let set = match parser.parse_one_of_keywords(&[Keyword::SET, Keyword::UNSET]) {
@@ -649,6 +654,37 @@ fn parse_alter_dynamic_table(parser: &mut Parser) -> Result<Statement, ParserErr
     }))
 }
 
+/// Parse snowflake alter external table.
+/// <https://docs.snowflake.com/en/sql-reference/sql/alter-external-table>
+fn parse_alter_external_table(parser: &mut Parser) -> Result<Statement, ParserError> {
+    let if_exists = parser.parse_keywords(&[Keyword::IF, Keyword::EXISTS]);
+    let table_name = parser.parse_object_name(true)?;
+
+    // Parse the operation (REFRESH for now, can be extended)
+    let operation = if parser.parse_keyword(Keyword::REFRESH) {
+        AlterTableOperation::Refresh
+    } else {
+        return parser.expected("REFRESH after ALTER EXTERNAL TABLE", parser.peek_token());
+    };
+
+    let end_token = if parser.peek_token_ref().token == Token::SemiColon {
+        parser.peek_token_ref().clone()
+    } else {
+        parser.get_current_token().clone()
+    };
+
+    Ok(Statement::AlterTable(AlterTable {
+        name: table_name,
+        if_exists,
+        only: false,
+        operations: vec![operation],
+        location: None,
+        on_cluster: None,
+        table_type: Some(AlterTableType::External),
+        end_token: AttachedToken(end_token),
+    }))
+}
+
 /// Parse snowflake alter session.
 /// <https://docs.snowflake.com/en/sql-reference/sql/alter-session>
 fn parse_alter_session(parser: &mut Parser, set: bool) -> Result<Statement, ParserError> {

src/parser/mod.rs

@@ -9778,6 +9778,7 @@ impl<'a> Parser<'a> {
             Keyword::POLICY,
             Keyword::CONNECTOR,
             Keyword::ICEBERG,
+            Keyword::EXTERNAL,
             Keyword::SCHEMA,
             Keyword::USER,
         ])?;
@@ -9789,10 +9790,14 @@ impl<'a> Parser<'a> {
             }
             Keyword::VIEW => self.parse_alter_view(),
             Keyword::TYPE => self.parse_alter_type(),
-            Keyword::TABLE => self.parse_alter_table(false),
+            Keyword::TABLE => self.parse_alter_table(None),
             Keyword::ICEBERG => {
                 self.expect_keyword(Keyword::TABLE)?;
-                self.parse_alter_table(true)
+                self.parse_alter_table(Some(AlterTableType::Iceberg))
+            }
+            Keyword::EXTERNAL => {
+                self.expect_keyword(Keyword::TABLE)?;
+                self.parse_alter_table(Some(AlterTableType::External))
             }
             Keyword::INDEX => {
                 let index_name = self.parse_object_name(false)?;
@@ -9822,7 +9827,10 @@ impl<'a> Parser<'a> {
     }
 
     /// Parse a [Statement::AlterTable]
-    pub fn parse_alter_table(&mut self, iceberg: bool) -> Result<Statement, ParserError> {
+    pub fn parse_alter_table(
+        &mut self,
+        table_type: Option<AlterTableType>,
+    ) -> Result<Statement, ParserError> {
         let if_exists = self.parse_keywords(&[Keyword::IF, Keyword::EXISTS]);
         let only = self.parse_keyword(Keyword::ONLY); // [ ONLY ]
         let table_name = self.parse_object_name(false)?;
@@ -9855,11 +9863,7 @@ impl<'a> Parser<'a> {
             operations,
             location,
             on_cluster,
-            table_type: if iceberg {
-                Some(AlterTableType::Iceberg)
-            } else {
-                None
-            },
+            table_type,
             end_token: AttachedToken(end_token),
         }
         .into())

tests/sqlparser_snowflake.rs

@@ -4635,3 +4635,9 @@ fn test_alter_dynamic_table() {
     snowflake().verified_stmt("ALTER DYNAMIC TABLE my_dyn_table SUSPEND");
     snowflake().verified_stmt("ALTER DYNAMIC TABLE my_dyn_table RESUME");
 }
+
+#[test]
+fn test_alter_external_table() {
+    snowflake().verified_stmt("ALTER EXTERNAL TABLE some_table REFRESH");
+    snowflake().verified_stmt("ALTER EXTERNAL TABLE my_database.my_schema.my_external_table REFRESH");
+}