查询所有表名与表说明，字段名与字段说明

--查询数据库所有表名与表说明

select a.name tableName, b.value tableComment
from sysobjects a
LEFT JOIN sys.extended_properties b ON a.id = b.major_id AND b.minor_id = 0
where xtype = 'u' order by tableName

--查询表的字段名，及对应的字段说明

select a.name tabname,a1.name '字段',b.value '字段描述（说明）'
from sysobjects a left join sys.columns a1 on a.id = a1.object_id
left join sys.extended_properties b on b.major_id = a.id and b.minor_id = a1.column_id
where a.name='tb_Company'

--可用于导出表结构到EXCEL

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