oracle依據註釋查詢表信息

-----------------------------------1：建表----------------------------------------
create table EMP
(
EMPNO NUMBER(4) PRIMARY KEY,
ENAME VARCHAR2(10),
JOB VARCHAR2(9),
MGR NUMBER(4),
HIREDATE DATE,
SAL NUMBER(7,2),
DEPNO NUMBER(4)
);
-----------------------------------2：添加表註釋--------------------------------
COMMENT ON TABLE EMP IS '學生信息表';
-----------------------------------3：添加字段註釋-----------------------------
COMMENT ON COLUMN EMP.EMPNO IS '學號';
COMMENT ON COLUMN EMP.ENAME IS '姓名';
COMMENT ON COLUMN EMP.JOB IS '郵箱';
COMMENT ON COLUMN EMP.MGR IS '性別';
COMMENT ON COLUMN EMP.HIREDATE IS '入職日期';
COMMENT ON COLUMN EMP.SAL IS '薪資';
COMMENT ON COLUMN EMP.DEPNO IS '部門編號';
-----------------------------------4：依據字段查詢表信息--------------------
select * from user_tab_columns where column_name='EMPNO';
-----------------------------------5：依據表名查詢字段信息-----------------
select A.COLUMN_NAME,A.DATA_TYPE  from user_tab_columns A
where TABLE_NAME='EMP';
-----------------------------------6：獲取表--------------------------------------
select table_name from user_tables; ---當前用戶擁有的表      
-----------------------------------7：依據表註釋獲取表信息------------------
select * from user_tab_comments where comments like '%xxx%';
-----------------------------------8：依據字段註釋獲取表/列信息------------
select * from user_col_comments where comments like '%xxx%';