在将这段代码编译为Oracle存储的过程时，我收到错误“不一致的数据类型：期望的游标得到CLOB”。我不知道如何将CLOB变量放入输出游标中。

CREATE OR REPLACE PROCEDURE sp_getPolygon 
(
    CityId IN INT,
    Out_CUR OUT SYS_REFCURSOR
) AS 
BEGIN
DECLARE
  cola_b_geom SDO_GEOMETRY;
  returned_json CLOB;
    BEGIN
    open Out_CUR for
        With cte as(SELECT GEOMETRY FROM GISBRANCHES WHERE "FBranchesId" IN (SELECT "Id" FROM "CreBranches" WHERE "FCitiesId" = CityId))
        SELECT GEOMETRY into cola_b_geom FROM cte;
        returned_json := SDO_UTIL.TO_GEOJSON(cola_b_geom);
        --dbms_output.put_line( returned_json );
        SELECT returned_json into Out_CUR FROM DUAL;
    END;
END sp_getPolygon;