oracle--查询表的信息 查看备注字段

SELECT A.COLUMN_NAME,   --字段名称

       A.DATA_TYPE,     --字段类型

       nvl(TO_char(A.DATA_LENGTH), ''),      -- 字段长度

       nvl(TO_char(A.DATA_PRECISION), ''),   -- 列相关数据类型(数字类型)的具体长度(有效位数),一个十进制数(NUMBER类型),或一个二进制树(FLOAT类型)   
       nvl(TO_char(A.DATA_SCALE), '')        -- 小数点位数
   FROM SYS.USER_TAB_COLUMNS A

 WHERE 1 = 1

   AND A.TABLE_NAME = '表名'

 

Oracle 下读取表/字段的备注信息

Oracle 通过COMMENT ON TABLE  /  COMMENT ON COLUMN 追加表/字段的备注。

 CREATE TABLE "MR_DEPT" (

       "DEPT_ID" NUMBER NOT NULL ,

       "PARENT_ID" NUMBER,

       "DEPT_NAME" CHAR(20) NOT NULL ,

       "STATUS" NUMBER DEFAULT 1 NOT NULL ,

PRIMARY KEY ("DEPT_ID")

);

 

COMMENT ON TABLE "MR_DEPT" IS '部门表';

COMMENT ON COLUMN "MR_DEPT"."DEPT_ID" IS '部门编号';

COMMENT ON COLUMN "MR_DEPT"."PARENT_ID" IS '上级部门编号';

COMMENT ON COLUMN "MR_DEPT"."DEPT_NAME" IS '部门名';

COMMENT ON COLUMN "MR_DEPT"."STATUS" IS '状态';

 

备注加好以后，如何在查询中检索呢？

 

查询表的备注信息

SELECT

  TABLE_NAME,

  TABLE_TYPE,

  COMMENTS

FROM

  USER_TAB_COMMENTS

WHERE

  TABLE_NAME = 'MR_DEPT';

 

 

查询字段的备注信息

SELECT

  TABLE_NAME,

  COLUMN_NAME,

  COMMENTS

FROM

  USER_COL_COMMENTS

WHERE

  TABLE_NAME = 'MR_DEPT';