using System.IO; 
using System.Data.OleDb; //连接Access数据库 
using ADOX;        
//引用COM：Microsoft ADO Ext. 2.8 for DDL and Security 
//添加引用：Microsoft ActioveX Data Objects 2.8 Library 

 string conn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName; 
//创建数据库 
 ADOX.Catalog catalog = new Catalog(); 
 try 
 { 
  catalog.Create(conn); 
 } 
 catch 
 {} 
 
 //连接数据库 
 ADODB.Connection cn = new ADODB.Connection(); 
 cn.Open(conn, null, null, -1);       
 catalog.ActiveConnection = cn; 
 
 //新建表 
 ADOX.Table table = new ADOX.Table(); 
 table.Name = "AdPlayList"; 
  
 ADOX.Column column = new ADOX.Column(); 
 column.ParentCatalog = catalog; 
 column.Type = ADOX.DataTypeEnum.adInteger; // 必须先设置字段类型 
 column.Name = "ID"; 
 column.DefinedSize = 9; 
 column.Properties["AutoIncrement"].Value = true; 
 table.Columns.Append(column, DataTypeEnum.adInteger, 0); 
 //设置主键 
 table.Keys.Append("PrimaryKey", ADOX.KeyTypeEnum.adKeyPrimary, "ID", "", ""); 
  
 table.Columns.Append("FileName", DataTypeEnum.adVarWChar, 50); 
 table.Columns.Append("FileDate", DataTypeEnum.adDate, 0); 
 table.Columns.Append("FileSize", DataTypeEnum.adInteger, 9); 
 table.Columns.Append("OrderID", DataTypeEnum.adInteger, 9); 
 table.Columns.Append("Sha1", DataTypeEnum.adVarWChar, 50); 
 
try 
 { 
  catalog.Tables.Append(table); 
 } 
 catch (Exception ex) 
 { 
  MessageBox.Show(ex.Message); 
 } 
 //此处一定要关闭连接，否则添加数据时候会出错 
  
 table = null; 
 catalog = null; 
 Application.DoEvents(); 
 cn.Close(); 

//创建不带密码的连接语句 
string conn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName; 
//创建加密码的连接语句，pwd是密码 

ALTER DATABASE PASSWORD [NewPassword] [OldPassword] 

 string conn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName + ";Jet OLEDB:Database password=" + openpwd; 
string sql = "ALTER DATABASE PASSWORD " + newpwd + " " + openpwd; 
ADODB.Connection cn = new ADODB.Connection(); 
cn.Mode = ADODB.ConnectModeEnum.adModeShareExclusive; 
cn.Open(conn, null, null, -1); 
// 执行 SQL 语句以更改密码。 
object num; 
cn.Execute(sql, out num, -1); 
 cn.Close();