Maison > Article > base de données > C#动态创建Access数据库,创建加密码Access数据库,更改Access密
以前工作中需要全新的Access数据库,可以复制数据库,也可以把新的数据库放到资源里面,用新数据库的时候释放出来,都感觉不爽,还是动态生成心理舒服。 生成数据库要使用ADO,首先添加引用。 using System.IO; using System.Data.OleDb; // 连接Access数据
以前工作中需要全新的Access数据库,可以复制数据库,也可以把新的数据库放到资源里面,用新数据库的时候释放出来,都感觉不爽,还是动态生成心理舒服。
生成数据库要使用ADO,首先添加引用。
<p><span>using</span><span> System.IO;<br></span><span>using</span><span> System.Data.OleDb; <br></span><span>//</span><span>连接Access数据库</span><span><br></span><span>using</span><span> ADOX; <br></span><span>//</span><span>引用COM:Microsoft ADO Ext. 2.8 for DDL and Security <br></span><span>//</span><span>添加引用:Microsoft ActioveX Data Objects 2.8 Library</span></p>
创建数据库:
然后使用ADODB创建数据库,直接看代码:
<span> 1:</span> <span>string</span> conn = <span>"Provider=Microsoft.Jet.OLEDB.4.0;Data Source="</span> + fileName;
<span> 2:</span>
<span> 3:</span> <span>//创建数据库</span>
<span> 4:</span> ADOX.Catalog catalog = <span>new</span> Catalog();
<span> 5:</span> <span>try</span>
<span> 6:</span> {
<span> 7:</span> catalog.Create(conn);
<span> 8:</span> }
<span> 9:</span> <span>catch</span>
<span> 10:</span> {}
<span> 11:</span>
<span> 12:</span>
<span> 13:</span> <span>//连接数据库</span>
<span> 14:</span> ADODB.Connection cn = <span>new</span> ADODB.Connection();
<span> 15:</span> cn.Open(conn, <span>null</span>, <span>null</span>, -1);
<span> 16:</span> catalog.ActiveConnection = cn;
<span> 17:</span>
<span> 18:</span> <span>//新建表</span>
<span> 19:</span> ADOX.Table table = <span>new</span> ADOX.Table();
<span> 20:</span> table.Name = <span>"AdPlayList"</span>;
<span> 21:</span>
<span> 22:</span> ADOX.Column column = <span>new</span> ADOX.Column();
<span> 23:</span> column.ParentCatalog = catalog;
<span> 24:</span> column.Type = ADOX.DataTypeEnum.adInteger; <span>// 必须先设置字段类型</span>
<span> 25:</span> column.Name = <span>"ID"</span>;
<span> 26:</span> column.DefinedSize = 9;
<span> 27:</span> column.Properties[<span>"AutoIncrement"</span>].Value = <span>true</span>;
<span> 28:</span> table.Columns.Append(column, DataTypeEnum.adInteger, 0);
<span> 29:</span> <span>//设置主键</span>
<span> 30:</span> table.Keys.Append(<span>"PrimaryKey"</span>, ADOX.KeyTypeEnum.adKeyPrimary, <span>"ID"</span>, <span>""</span>, <span>""</span>);
<span> 31:</span>
<span> 32:</span> table.Columns.Append(<span>"FileName"</span>, DataTypeEnum.adVarWChar, 50);
<span> 33:</span> table.Columns.Append(<span>"FileDate"</span>, DataTypeEnum.adDate, 0);
<span> 34:</span> table.Columns.Append(<span>"FileSize"</span>, DataTypeEnum.adInteger, 9);
<span> 35:</span> table.Columns.Append(<span>"OrderID"</span>, DataTypeEnum.adInteger, 9);
<span> 36:</span> table.Columns.Append(<span>"Sha1"</span>, DataTypeEnum.adVarWChar, 50);
<span> 37:</span>
<span> 38:</span> <span>try</span>
<span> 39:</span> {
<span> 40:</span> catalog.Tables.Append(table);
<span> 41:</span> }
<span> 42:</span> <span>catch</span> (Exception ex)
<span> 43:</span> {
<span> 44:</span> MessageBox.Show(ex.Message);
<span> 45:</span> }
<span> 46:</span> <span>//此处一定要关闭连接,否则添加数据时候会出错</span>
<span> 47:</span>
<span> 48:</span> table = <span>null</span>;
<span> 49:</span> catalog = <span>null</span>;
<span> 50:</span> Application.DoEvents();
<span> 51:</span> cn.Close();
创建加密码数据库:
创建加密数据库的时候可把我难住了,因为在Access中加密码的时候是以独占方式打开,然后加密码。所以总是想创建完数据库以后再加密,试了试没有成功,最后转变一下思想,在生成的时候加密码怎么样,一试果然成功了。
<span> 1:</span> <span>//创建不带密码的连接语句</span>
<span> 2:</span> <span>string</span> conn = <span>"Provider=Microsoft.Jet.OLEDB.4.0;Data Source="</span> + fileName;
<span> 3:</span> <span>//创建加密码的连接语句,pwd是密码</span>
<span> 4:</span> <span>string</span> conn = <span>"Provider=Microsoft.Jet.OLEDB.4.0;Data Source="</span> + fileName + <span>";<br> Jet OLEDB:Database Password="</span> + Pwd + <span>";Jet OLEDB:Engine Type=5"</span>;
更改数据库密码:
SQL更改数据库密码的语句是:
<p><span>ALTER</span><span>DATABASE</span><span> PASSWORD </span><span>[</span><span>NewPassword</span><span>]</span><span>[</span><span>OldPassword</span><span>]</span></p>
用OleDbConnection打开数据库执行此SQL语句根本不行,所以我就用ADODB打开数据库执行,但是报以下错误:
给Access添加密码的时候会要求以“是以独占方式打开”,所以要设置打开的模式,详细说明如下:
ADO ConnectModeEnum含义 设置或返回以下某个 ConnectModeEnum 的值。
常量 说明
AdModeUnknown 默认值。表明权限尚未设置或无法确定。
AdModeRead 表明权限为只读。
AdModeWrite 表明权限为只写。
AdModeReadWrite 表明权限为读/写。
AdModeShareDenyRead 防止其他用户使用读权限打开连接。
AdModeShareDenyWrite 防止其他用户使用写权限打开连接。
AdModeShareExclusive 防止其他用户打开连接。
AdModeShareDenyNone 防止其他用户使用任何权限打开连接。
更改数据库代码如下:
<span> 1:</span> <span>string</span> conn = <span>"Provider=Microsoft.Jet.OLEDB.4.0;Data Source="</span> + fileName + <span>";<br> Jet OLEDB:Database password="</span> + openpwd;
<span> 2:</span> <span>string</span> sql = <span>"ALTER DATABASE PASSWORD "</span> + newpwd + <span>" "</span> + openpwd;
<span> 3:</span> ADODB.Connection cn = <span>new</span> ADODB.Connection();
<span> 4:</span> cn.Mode = ADODB.ConnectModeEnum.adModeShareExclusive;
<span> 5:</span> cn.Open(conn, <span>null</span>, <span>null</span>, -1);
<span> 6:</span> <span>// 执行 SQL 语句以更改密码。</span>
<span> 7:</span> <span>object</span> num;
<span> 8:</span> cn.Execute(sql, <span>out</span> num, -1);
<span> 9:</span> cn.Close();
如果你要忘了加的密码,可以使用使用密码查看工具“破解密码unaccess”,在代码里面文件夹里呢。
代码下载
http://cid-4b517bbe6c0b58a0.office.live.com/self.aspx/.Public/cnblogsCsharp/CreateAccess.rar