---1.查詢數據庫中的所有數據庫名：
SELECT Name FROM Master..SysDatabases ORDER BY Name
---2.查詢某個數據庫中所有的表名：
SELECT Name FROM SysObjects Where XType='U' ORDER BY Name --讀取庫中的所有表名 cafe
---3.查詢指定表名中的表結構信息：
SELECT (case when a.colorder=1 then d.name else null end) 表名, ( d.name) 表名2,
a.colorder 字段序號,a.name 字段名,
(case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else '' end) 標識,
(case when (SELECT count(*) FROM sysobjects
WHERE (name in (SELECT name FROM sysindexes
WHERE (id = a.id) AND (indid in
(SELECT indid FROM sysindexkeys
WHERE (id = a.id) AND (colid in
(SELECT colid FROM syscolumns WHERE (id = a.id) AND (name = a.name)))))))
AND (xtype = 'PK'))>0 then '√' else '' end) 主鍵,b.name 類型,a.length 佔用字節數,
COLUMNPROPERTY(a.id,a.name,'PRECISION') as 長度,
isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0) as 小數位數,(case when a.isnullable=1 then '√'else '' end) 允許空,
isnull(e.text,'') 默認值,isnull(g.[value], ' ') AS [說明]
FROM syscolumns a
left join systypes b on a.xtype=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.class and f.minor_id=0
--where b.name is not null
WHERE d.name='UsersRelation' --如果只查詢指定表,加上此條件 如果去掉則是查詢全部的
order by a.id,a.colorder
