修改varchar 爲 clob

alter table QITIS.TT_QPMS_MQS_ISSUE add ISSUE_DESC_up clob;
update QITIS.TT_QPMS_MQS_ISSUE set ISSUE_DESC_up = ISSUE_DESC;
alter table QITIS.TT_QPMS_MQS_ISSUE drop column  ISSUE_DESC;
alter table QITIS.TT_QPMS_MQS_ISSUE rename column ISSUE_DESC_up to ISSUE_DESC;