sql语句查询表的字段类型长度和表说明

打开查询分析器，执行下面的代码就可以了， 不需要修改任何地方。

SELECT sysobjects.name AS 表名, syscolumns.name AS 列名,
systypes.name AS 数据类型, syscolumns.length AS 数据长度, CONVERT(char,
sysproperties.[value]) AS 注释
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 CONVERT(char,sysproperties.[value]) <> 'null' --导出注释不为'null'的记录
--AND (sysobjects.name = 'bbs_bank_log') --逐个关联表名，可以用or连接条件
ORDER BY 表名

如果需要查询指定表的指定列可以添加查询条件：

and sysobjects.name='指定表名称' and syscolumns.name='指定列名'

修改字段属性：

ALTER TABLE table

{

[ ALTER COLUMN column_name

{

new_data_type [ ( precision [ , scale ] ) ]

[ COLLATE < collation_name > ]

[ NULL | NOT NULL ]

| {ADD | DROP } ROWGUIDCOL }

]
| ADD

{

[ < column_definition > ]
| column_name AS computed_column_expression

}

[ ,...n ]

| [ WITH CHECK | WITH NOCHECK ] ADD

{

 < table_constraint > }[ ,...n ] 

| DROP

{

[ CONSTRAINT ] constraint_name

| COLUMN column

}

[ ,...n ] 

| { CHECK | NOCHECK } CONSTRAINT

{

 ALL | constraint_name[ ,...n ] }

| { ENABLE | DISABLE } TRIGGER

{

 ALL | trigger_name[ ,...n ] }
}