Added alter external table .. add partition column support

Author: romanoff

src/ast/ddl.rs

@@ -375,6 +375,13 @@ pub enum AlterTableOperation {
     ///
     /// Note: this is Snowflake specific for dynamic tables <https://docs.snowflake.com/en/sql-reference/sql/alter-table>
     Refresh,
+    /// `ADD PARTITION COLUMN <column_name> <data_type>`
+    ///
+    /// Note: this is Snowflake specific for external tables <https://docs.snowflake.com/en/sql-reference/sql/alter-external-table>
+    AddPartitionColumn {
+        column_name: Ident,
+        data_type: DataType,
+    },
     /// `SUSPEND`
     ///
     /// Note: this is Snowflake specific for dynamic tables <https://docs.snowflake.com/en/sql-reference/sql/alter-table>
@@ -866,6 +873,12 @@ impl fmt::Display for AlterTableOperation {
             AlterTableOperation::Refresh => {
                 write!(f, "REFRESH")
             }
+            AlterTableOperation::AddPartitionColumn {
+                column_name,
+                data_type,
+            } => {
+                write!(f, "ADD PARTITION COLUMN {column_name} {data_type}")
+            }
             AlterTableOperation::Suspend => {
                 write!(f, "SUSPEND")
             }

src/ast/spans.rs

@@ -1146,6 +1146,7 @@ impl Spanned for AlterTableOperation {
             AlterTableOperation::SuspendRecluster => Span::empty(),
             AlterTableOperation::ResumeRecluster => Span::empty(),
             AlterTableOperation::Refresh => Span::empty(),
+            AlterTableOperation::AddPartitionColumn { column_name, .. } => column_name.span,
             AlterTableOperation::Suspend => Span::empty(),
             AlterTableOperation::Resume => Span::empty(),
             AlterTableOperation::Algorithm { .. } => Span::empty(),

src/dialect/snowflake.rs

@@ -668,9 +668,16 @@ fn parse_alter_external_table(parser: &mut Parser) -> Result<Statement, ParserEr
         AlterTableOperation::RenameTable {
             table_name: RenameTableNameKind::To(new_table_name),
         }
+    } else if parser.parse_keywords(&[Keyword::ADD, Keyword::PARTITION, Keyword::COLUMN]) {
+        let column_name = parser.parse_identifier()?;
+        let data_type = parser.parse_data_type()?;
+        AlterTableOperation::AddPartitionColumn {
+            column_name,
+            data_type,
+        }
     } else {
         return parser.expected(
-            "REFRESH or RENAME TO after ALTER EXTERNAL TABLE",
+            "REFRESH, RENAME TO, or ADD PARTITION COLUMN after ALTER EXTERNAL TABLE",
             parser.peek_token(),
         );
     };

tests/sqlparser_snowflake.rs

@@ -4641,4 +4641,5 @@ 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");
     snowflake().verified_stmt("ALTER EXTERNAL TABLE some_table RENAME TO new_table_name");
+    snowflake().verified_stmt("ALTER EXTERNAL TABLE some_table ADD PARTITION COLUMN column_name VARCHAR");
 }