修改數據庫字段類型或名字

 ########WF_WORK_FLOW_LOG修改字段類型

1. ##修改原字段名NAME為NAME_TMP

 ALTER TABLE WF_WORK_FLOW_LOG RENAME COLUMN WORK_WHOLE_FLOW TO WORK_WHOLE_FLOW_TMP; 

2.##增加一個和原字段名同名的字段NAME

 ALTER TABLE WF_WORK_FLOW_LOG ADD WORK_WHOLE_FLOW CLOB; 

3.##將原字段NAME_TMP數據更新到增加的字段NAME

 UPDATE WF_WORK_FLOW_LOG SET WORK_WHOLE_FLOW=TRIM(WORK_WHOLE_FLOW_TMP); 

4.##更新完，刪除原字段NAME_TMP

 ALTER TABLE WF_WORK_FLOW_LOG DROP COLUMN WORK_WHOLE_FLOW_TMP;