Preserve quoted identifiers and spans in Snowflake COPY transformations

src/dialect/snowflake.rs

@@ -1785,7 +1785,11 @@ fn parse_select_item_for_data_load(
             Ok(())
         }
         Token::Word(w) => {
-            alias = Some(Ident::new(w.value));
+            alias = Some(Ident {
+                value: w.value,
+                quote_style: w.quote_style,
+                span: next_token.span,
+            });
             Ok(())
         }
         _ => parser.expected("alias or file_col_num", next_token),
@@ -1810,10 +1814,17 @@ fn parse_select_item_for_data_load(
     match parser.next_token().token {
         Token::Colon => {
             // parse element
-            element = Some(Ident::new(match parser.next_token().token {
-                Token::Word(w) => Ok(w.value),
-                _ => parser.expected_ref("file_col_num", parser.peek_token_ref()),
-            }?));
+            element = Some(match parser.next_token() {
+                TokenWithSpan {
+                    token: Token::Word(w),
+                    span,
+                } => Ident {
+                    value: w.value,
+                    quote_style: w.quote_style,
+                    span,
+                },
+                token => return parser.expected("file_col_num", token),
+            });
         }
         _ => {
             // element not present move back
@@ -1835,10 +1846,17 @@ fn parse_select_item_for_data_load(
 
     // as
     if parser.parse_keyword(Keyword::AS) {
-        item_as = Some(match parser.next_token().token {
-            Token::Word(w) => Ok(Ident::new(w.value)),
-            _ => parser.expected_ref("column item alias", parser.peek_token_ref()),
-        }?);
+        item_as = Some(match parser.next_token() {
+            TokenWithSpan {
+                token: Token::Word(w),
+                span,
+            } => Ident {
+                value: w.value,
+                quote_style: w.quote_style,
+                span,
+            },
+            token => return parser.expected("column item alias", token),
+        });
     }
 
     Ok(StageLoadSelectItem {

tests/sqlparser_snowflake.rs

@@ -2751,6 +2751,37 @@ fn test_copy_into_with_transformations() {
     snowflake().parse_sql_statements(sql1).unwrap();
 }
 
+#[test]
+fn test_copy_into_staged_identifiers_preserve_quotes_and_spans() {
+    let sql = r#"COPY INTO t FROM (SELECT "src".$1:"field" AS "Mixed" FROM @stage AS "src")"#;
+    snowflake().verified_stmt(sql);
+    let Statement::CopyIntoSnowflake {
+        from_transformations: Some(items),
+        ..
+    } = sqlparser::parser::Parser::parse_sql(&SnowflakeDialect {}, sql)
+        .unwrap()
+        .remove(0)
+    else {
+        panic!("expected COPY INTO with transformations");
+    };
+    let StageLoadSelectItemKind::StageLoadSelectItem(item) = &items[0] else {
+        panic!("expected a staged field");
+    };
+    for (ident, source) in [
+        (item.alias.as_ref().unwrap(), "\"src\""),
+        (item.element.as_ref().unwrap(), "\"field\""),
+        (item.item_as.as_ref().unwrap(), "\"Mixed\""),
+    ] {
+        assert_eq!(ident.quote_style, Some('"'));
+        assert_eq!(ident.span.start.line, 1);
+        assert_eq!(
+            usize::try_from(ident.span.start.column).unwrap(),
+            sql.find(source).unwrap() + 1
+        );
+    }
+    assert_eq!(items[0].to_string(), r#""src".$1:"field" AS "Mixed""#);
+}
+
 #[test]
 fn test_copy_into_with_nested_transformation_path() {
     let sql = concat!(