您可以尝试以下方法:
alter table my_table add (new_column varchar2(1000));
update my_table set new_column=dbms_lob.substr(old_column,1000,1);
经过 :
alter table my_table drop column old_column
alter table my_table rename column new_column to old_column
如何将dataype CLOB更改为VARCHAR2(sql)
您可以尝试以下方法:
alter table my_table add (new_column varchar2(1000));
update my_table set new_column=dbms_lob.substr(old_column,1000,1);
经过 :
alter table my_table drop column old_column
alter table my_table rename column new_column to old_column