刚刚学习数据库，写了一个连接SQL Sever数据库的代码，但总是连接失败，总有异常出现，看书检查，和书上也没有很么出入，实在不知道该如何去做，请大家帮忙看看

OleDbConnection subjectDatabase = new OleDbConnection();
OleDbDataAdapter subjectDaDatabase = new OleDbDataAdapter();
OleDbCommand subjectSelect = new OleDbCommand();
OleDbCommand subjectInsert = new OleDbCommand();
OleDbCommand subjectUpdata = new OleDbCommand();
OleDbCommand subjectDelete = new OleDbCommand();
DataSet subjectDset = new DataSet();
DataTable subjectDtable = new DataTable();

private void ConnectDatabase()
{
subjectDatabase.ConnectionString = "Provider=SQLOLEDB;Data Source=YIDEZHI\\SQLEXPRESS;Initial Catalog=e:\\数据库\\subject\\data\\subject.mdf;User ID=YIDEZHI;pwd=;";
DataTableMapping tableName = new DataTableMapping();
tableName = subjectDaDatabase.TableMappings.Add("Table", "suject");
subjectSelect.CommandText = "SELECT * FROM subject";
subjectSelect.Connection = subjectDatabase;
subjectDaDatabase.SelectCommand = subjectSelect;
subjectDaDatabase.Fill(subjectDset);
}


subjectDaDatabase.Fill(subjectDset)这一句总是有异常产生，不知道到底该怎么样解决，请大家帮忙看看该如何去做，谢谢。

[此贴子已经被作者于2007-10-24 14:48:06编辑过]

水贴.鉴定完毕

SqlAdapter da = new ("查询语句","server=.;uid=sa;pwd=;database=你的数据库");
DataTable dt = new DataTable();
da.Full(dt);
控件.DataSoure=dt;

水贴.鉴定完毕

不好意思，刚才是帖子还没有写完，不小心点到了发表，所以赶快编辑了，望大家原谅

阿，标注的初学者！

你连接都没开启！

楼上的朋友
什么意思啊，不太明白

subjectDatabase.Open()
你是说的这一句吗，我写上过，不过写上后出现异常的就是这个语句了
我有一个连接数据库的实例代码，里面就没有这个语句，但是可以正常运行，不过那个是连接的access数据库

OleDbConnection subjectDatabase = new OleDbConnection();
OleDbDataAdapter subjectDaDatabase = new OleDbDataAdapter();
OleDbCommand subjectSelect = new OleDbCommand();
DataSet subjectDset = new DataSet();

private void ConnectDatabase()
{
subjectDatabase.ConnectionString = "Provider=SQLOLEDB;Data Source=YIDEZHI\\SQLEXPRESS;Initial Catalog=e:\\数据库\\subject\\data\\subject.mdf;User ID=YIDEZHI;pwd=;";
subjectDatabase.open();
subjectSelect.CommandText = "SELECT * FROM subject";
subjectSelect.Connection = subjectDatabase;
subjectDaDatabase.SelectCommand = subjectSelect;
subjectDaDatabase.Fill(subjectDset,"suject");
}