初学C#,请各位大侠指点~DataSet dataset=new DataSet();
string sql="select * from teacher";
SqlDataAdapter dataAdapter=new SqlDataAdapter(sql,dbconnect.connection)
dataAdapter.Fill(dataset,"teacher") ....程序继续向下执行sql="select * from student"; //此处sql变量的值变了,怎么重新检索数据呢,已经声明了一个DataAdapter对象了,不用再重新生成一个DataAdapter对象吧---------------------
我目前的解决方法:
DataSet dataSet = new DataSet();
string sql = "select * from teacher";
SqlCommand command = new SqlCommand(sql, dbConnect.connection);
SqlDataAdapter dataAdapter = new SqlDataAdapter();
dataAdapter.SelectCommand = command;
dataAdapter.Fill(dataSet, "teacher");sql = "select * from student"; //此处sql变量的值变了
command.CommandText = sql;
dataAdapter.SelectCommand = command;
dataAdapter.Fill(dataSet, "student");
不知道有更简便的写法吗? 这样写感觉有些啰嗦了。
string sql="select * from teacher";
SqlDataAdapter dataAdapter=new SqlDataAdapter(sql,dbconnect.connection)
dataAdapter.Fill(dataset,"teacher") ....程序继续向下执行sql="select * from student"; //此处sql变量的值变了,怎么重新检索数据呢,已经声明了一个DataAdapter对象了,不用再重新生成一个DataAdapter对象吧---------------------
我目前的解决方法:
DataSet dataSet = new DataSet();
string sql = "select * from teacher";
SqlCommand command = new SqlCommand(sql, dbConnect.connection);
SqlDataAdapter dataAdapter = new SqlDataAdapter();
dataAdapter.SelectCommand = command;
dataAdapter.Fill(dataSet, "teacher");sql = "select * from student"; //此处sql变量的值变了
command.CommandText = sql;
dataAdapter.SelectCommand = command;
dataAdapter.Fill(dataSet, "student");
不知道有更简便的写法吗? 这样写感觉有些啰嗦了。
public dataset sqlstring(string sql)
{
DataSet dataSet = new DataSet();
SqlCommand command = new SqlCommand(sql, dbConnect.connection);
SqlDataAdapter dataAdapter = new SqlDataAdapter();
dataAdapter.SelectCommand = command;
dataAdapter.Fill(dataSet);
return dataSet;}
包括数据库操作辅助类, 可以5行完成 SqlDataAdapterSqlHelper sql = new SqlHelper("连接字符串");DataSet a = sql.ExecuteDataSet("SQL");
// 下面是 SqlDataAdapter 的示例:
sql.Sql = "SQL ";
obj.DataSoruce = sql.DataSoruce ; // 从数据库获取一个数据源sql.DataSoruce = obj.DataSoruce ; // 把数据源保存到数据库
然后执行一下Fill();
SqlDataAdapter da = new SqlDataAdapter("Select * from a", cn);
DataSet ds = new DataSet();
cn.Open();
da.Fill(ds, "a");
cn.Close(); //更新
ds.Tables[0].Rows[1]["yName"] = "";
cn.Open();
SqlCommandBuilder cmd = new SqlCommandBuilder(da);
da.Update(ds.Tables[0]);
cn.Close();
SqlConnection cn=new SqlConnection("连接字符串");
SqlDataAdapter da=new SqlDataAdapter("sql语句1",cn);
DataSet ds=new DataSet();
cn.Open();//可以不要
da.Fill(ds,"table1");
da.SelectCommand.CommandText="sql语句2";
da.Fill(ds,"table2");
cn.Close();//可以不要