Oracle数据库中字段类型CLOB修改为VARCHER

需求： PI6000.AUT_OM_JXSQ_DD表中GLXX字段类型为CLOB，需要修改为VARCHAR

ALTER TABLE PI6000.AUT_OM_JXSQ_DD ADD(C VARCHAR2(4000));

UPDATE PI6000.AUT_OM_JXSQ_DD SET C = GLXX;

ALTER TABLE PI6000.AUT_OM_JXSQ_DD  DROP COLUMN GLXX;

ALTER TABLE PI6000.AUT_OM_JXSQ_DD RENAME COLUMN C TO GLXX;