Fix parse COPY INTO stage names without parens for SnowFlake (apache#1187)

Signed-off-by: Maciej Obuchowski <obuchowski.maciej@gmail.com>

Author: mobuchowski

src/dialect/snowflake.rs

@@ -155,6 +155,10 @@ pub fn parse_stage_name_identifier(parser: &mut Parser) -> Result<Ident, ParserE
                 parser.prev_token();
                 break;
             }
+            Token::RParen => {
+                parser.prev_token();
+                break;
+            }
             Token::AtSign => ident.push('@'),
             Token::Tilde => ident.push('~'),
             Token::Mod => ident.push('%'),
@@ -219,7 +223,7 @@ pub fn parse_copy_into(parser: &mut Parser) -> Result<Statement, ParserError> {
         }
         _ => {
             parser.prev_token();
-            from_stage = parser.parse_object_name(false)?;
+            from_stage = parse_snowflake_stage_name(parser)?;
             stage_params = parse_stage_params(parser)?;
 
             // as

tests/sqlparser_snowflake.rs

@@ -1337,6 +1337,48 @@ fn test_snowflake_stage_object_names() {
     }
 }
 
+#[test]
+fn test_snowflake_copy_into() {
+    let sql = "COPY INTO a.b FROM @namespace.stage_name";
+    assert_eq!(snowflake().verified_stmt(sql).to_string(), sql);
+    match snowflake().verified_stmt(sql) {
+        Statement::CopyIntoSnowflake {
+            into, from_stage, ..
+        } => {
+            assert_eq!(into, ObjectName(vec![Ident::new("a"), Ident::new("b")]));
+            assert_eq!(
+                from_stage,
+                ObjectName(vec![Ident::new("@namespace"), Ident::new("stage_name")])
+            )
+        }
+        _ => unreachable!(),
+    }
+}
+
+#[test]
+fn test_snowflake_copy_into_stage_name_ends_with_parens() {
+    let sql = "COPY INTO SCHEMA.SOME_MONITORING_SYSTEM FROM (SELECT t.$1:st AS st FROM @schema.general_finished)";
+    assert_eq!(snowflake().verified_stmt(sql).to_string(), sql);
+    match snowflake().verified_stmt(sql) {
+        Statement::CopyIntoSnowflake {
+            into, from_stage, ..
+        } => {
+            assert_eq!(
+                into,
+                ObjectName(vec![
+                    Ident::new("SCHEMA"),
+                    Ident::new("SOME_MONITORING_SYSTEM")
+                ])
+            );
+            assert_eq!(
+                from_stage,
+                ObjectName(vec![Ident::new("@schema"), Ident::new("general_finished")])
+            )
+        }
+        _ => unreachable!(),
+    }
+}
+
 #[test]
 fn test_snowflake_trim() {
     let real_sql = r#"SELECT customer_id, TRIM(sub_items.value:item_price_id, '"', "a") AS item_price_id FROM models_staging.subscriptions"#;