SELECT * FROM Master..SysDatabases ORDER BY NameSELECT Name,* FROM Master..SysDatabases  where Name=‘TestDB‘SELECT COLUMN_NAME,DATA_TYPE FROM INFORMATION_SCHEMA.columns WHERE TABLE_CATALOG like ‘%TestDB%‘SELECT * FROM INFORMATION_SCHEMA.columns SELECT * FROM INFORMATION_SCHEMA.columns WHERE TABLE_NAME like ‘%Com_UserLogin%‘

string connectionString = "Server=.;UID=‘" + uid + "‘;PWD=‘" + pwd + "‘;DATABASE=‘" + db + "‘";            string[] restriction = new string[4];            restriction[1] = "dbo";            SqlConnection conn = new SqlConnection(connectionString);            conn.Open();            DataTable dt = conn.GetSchema("Tables", restriction);

 SELECT  (case when a.colorder=1 then d.name else ‘‘ end) 表名,a.colorder 字段序号,a.name 字段名, (case when COLUMNPROPERTY( a.id,a.name,‘IsIdentity‘)=1 then ‘√‘else ‘‘ end) 标识, (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) 主键,b.name 类型,a.length 占用字节数,COLUMNPROPERTY(a.id,a.name,‘PRECISION‘) as 长度,isnull(COLUMNPROPERTY(a.id,a.name,‘Scale‘),0) as 小数位数, (case when a.isnullable=1 then ‘√‘else ‘‘ end) 允许空,isnull(e.text,‘‘) 默认值,isnull(g.[value],‘‘) AS 字段说明    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  --where d.name in (‘Contact‘,‘StockBmps‘,‘AddressType‘)---查询具体的表，注释掉后就是查询整个数据库了order by a.id,a.colorder