SELECT 
表名 = CASE WHEN A.COLORDER=1 THEN D.NAME ELSE '' END,
表备注 = CASE WHEN A.COLORDER=1 THEN ISNULL(F.VALUE,'') ELSE '' END,
列序号 = A.COLORDER,
列名称 = A.NAME,
标识 = CASE WHEN COLUMNPROPERTY(A.ID,A.NAME,'ISIDENTITY')=1 THEN '√ ' ELSE '' END,
主键 = CASE WHEN EXISTS(SELECT 1 FROM SYSOBJECTS WHERE XTYPE='PK' AND PARENT_OBJ=A.ID AND NAME IN (
SELECT NAME FROM SYSINDEXES WHERE INDID IN(
SELECT INDID FROM SYSINDEXKEYS WHERE ID=A.ID AND COLID=A.COLID))) THEN '√' ELSE '' END,
类型 = B.NAME,
字节 = A.LENGTH,
长度 = COLUMNPROPERTY(A.ID,A.NAME,'PRECISION'),
小数位 = ISNULL(COLUMNPROPERTY(A.ID,A.NAME,'SCALE'),0),
允许空 = CASE WHEN A.ISNULLABLE=1 THEN '√ 'ELSE '' END,
默认值 = ISNULL(E.TEXT,''),
列备注 = ISNULL(G.[VALUE],'')
FROM 
SYSCOLUMNS A
LEFT JOIN SYSTYPES B ON A.XUSERTYPE=B.XUSERTYPE
INNER JOIN SYSOBJECTS D ON A.ID=D.ID AND D.XTYPE='U ' --AND D.NAME<>'DTPROPERTIES'
LEFT JOIN SYSCOMMENTS E ON A.CDEFAULT=E.ID
LEFT JOIN sys.extended_properties G ON A.ID=G.major_id AND A.COLID=G.minor_id   
LEFT JOIN sys.extended_properties F ON D.ID=F.major_id AND F.minor_id=0

--where D.NAME='tbname'   --查询这个表

ORDER BY A.ID,A.COLORDER

SELECT A.COLUMN_NAME AS columnName,
       A.DATA_TYPE   AS columnType,
       A.CHAR_LENGTH AS charLength,
       A.NULLABLE    AS isNullAble,
       B.comments    AS columnComment
FROM all_tab_columns A,
     DBA_COL_COMMENTS B
WHERE A.OWNER = B.OWNER
  AND A.table_name = B.table_name
  AND A.COLUMN_NAME = B.COLUMN_NAME
  AND A.OWNER = #{dbName} -- 数据库名
  AND A .TABLE_NAME = #{tableName} -- 表名

SELECT
    column_name as columnName,
    column_type as columnType,
    is_nullable as isNullAble,
    COLUMN_DEFAULT as columnDefault,
    column_comment as columnComment,
CHARACTER_MAXIMUM_LENGTH as charLength
FROM
    information_schema.COLUMNS
WHERE
    table_schema = #{dbName} -- 数据库名
        AND table_name = #{tableName} -- 表名