获取数据库中所有表的列名
SELECT SysColumns.name AS Columnsname, SysObjects.name AS Tablename FROM SysObjects, SysColumns WHERE Sysobjects.Xtype='u' AND Sysobjects.Id=Syscolumns.Id

获取SQL所有数据库名、所有表名、所有字段名、表字段长度
1.获取MSSQL中的所有数据库名:
SELECT name FROM MASter..SysDatabASes ORDER BY name

2.获取MSSQL中的所有用户表名:
SELECT name FROM DatabASename..SysObjects WHERE XType='U' ORDER BY name
XType='U':表示所有用户表;
XType='S':表示所有系统表;

3.获取指定表[tb_phone]的所有字段名:
SELECT name FROM SysColumns WHERE id=Object_Id('tb_phone')

4.SQL所有表的表名、所有字段名、表字段长度
SELECT table_name AS 数据表名,
column_name AS 字段名,
ISNULL(column_default,'') AS 默认值,
is_nullable AS 是否允许为NULL,
data_type AS 数据类型,
ISNULL(ISNULL(ISNULL(character_maximum_length,numeric_precision),datetime_precision),1) AS 类型长度
FROM information_schema.columns
WHERE NOT table_name IN('sysdiagrams','dtproperties')

5.获取指定表[tb_phone]的表名，表字段名，字段类型和类型长度
SELECT SysObjects.name AS Tablename,
Syscolumns.name AS Columnsname,
Systypes.name AS DateType,
Syscolumns.length AS DateLength
FROM Sysproperties RIGHT OUTER JOIN
Sysobjects INNER JOIN
Syscolumns ON Sysobjects.id = Syscolumns.id INNER JOIN
Systypes ON Syscolumns.xtype = Systypes.xtype ON
Sysproperties.id = Syscolumns.id AND
Sysproperties.smallid = Syscolumns.colid
WHERE (Sysobjects.xtype = 'u' OR
Sysobjects.xtype = 'v') AND (Systypes.name <> 'Sysname') AND
(Sysobjects.name = 'tb_phone')
ORDER BY Columnsname