几个简单的与数据库连接,请以通俗点的语言给个注释 谢谢了
OleDbConnection objConnection=new OleDbConnection(strConnection);sql = "select * from Userinfo where Username = '"+Username.Text+"'";OleDbCommand Mycmd = new OleDbCommand(sql,objConnection);objConnection.Open();OleDbDataReader rs;
rs=Mycmd.ExecuteReader();
OleDbConnection objConnection=new OleDbConnection(strConnection);sql = "select * from Userinfo where Username = '"+Username.Text+"'";OleDbCommand Mycmd = new OleDbCommand(sql,objConnection);objConnection.Open();OleDbDataReader rs;
rs=Mycmd.ExecuteReader();
OleDbConnection objConnection=new OleDbConnection(strConnection);//SQL 查询语句
sql = "select * from Userinfo where Username = '"+Username.Text+"'";//根据连接和SQL语句创建一个Comman对象
OleDbCommand Mycmd = new OleDbCommand(sql,objConnection);//打开连接
objConnection.Open();OleDbDataReader rs;
rs=Mycmd.ExecuteReader();
//首先创建一个数据库连接对象sql = "select * from Userinfo where Username = '"+Username.Text+"'";
//SQL 查询语句,也就是从UserInfo表中查询数据.OleDbCommand Mycmd = new OleDbCommand(sql,objConnection);
//根据连接和SQL语句创建一个Comman对象objConnection.Open();
//打开连接对象OleDbDataReader rs;
//定义一个OleDbDataReader对象,也就是创建一个提供从数据源读取数据行的只进流的方法。
rs=Mycmd.ExecuteReader();
//读取数据
多看看这个