Oracle查詢070430

問題是:把職工資訊表中的職工姓名的姓改為另一個.如:把張某改為王某,只改姓而不改名字:
update 表名 set 欄位名 = '王' || substr(欄位名,2,length(欄位名)) where 欄位名 like '張%';
表名是recv，裡面有欄位no讓no欄位為遞增:
create sequence
start with 1
increment by 1;
查詢所有使用者表及其相應欄位的類型:
select *From user_tab_columns;
Oracle使用SQL查詢表欄位列的備忘資訊:
select comments  
from user_col_comments  
where table_name = 'dept'
and column_name = 'DEPTNO';
用SQL語句擷取Oracle指定表的表結構:1、SELECT * FROM ALL_TAB_COLUMNS where owner='USE1' and table_name ='B';  2、desc 表名 3、SELECT column_name AS FIELDNAME,data_type AS TYPE,data_length AS SIZE,nullable AS ISNULL FROM user_tab_columns where table_name = 'tablename'  
Oracel中查詢使用者表中某表某列的欄位類型:
select *from user_tab_columns where table_name='dept' and column_name='DEPTNO';