PL/SQL to update all columns【代码】

undefine schema_name; declare l_Err varchar2(200); beginfor r in (select atc.table_name, atc.column_name, atc.data_lengthfrom all_tab_columns atc, all_tables tab WHERE atc.owner=tab.OWNER and atc.table_name=tab.table_nameand atc.data_type = VARCHAR2and atc.char_used = B --Indicates that the column uses BYTE length semantics (B) or CHAR length semantics (C) -- and atc...