ADO.NET的连接式和断开式

SqlConnection sqlConn=new SqlConnection("server=.;database=pubs;
user id=sa;password=;");

SqlCommand sqlComm=new SqlCommand("select * from authors",sqlConn);

//操作在打开和断开数据库之间

sqlConn.Open();

SqlDataReader dr=sqlComm.ExcuteReader();

while(dr.Read())

{

for  (int i=0; i<dr.FieldCount; i++) 

{

Console.Write(dr.GetValue(i).ToString()+" ");

}

Console.WriteLine();

}

dr.Close();

sqlConn.Close();

SqlConnection sqlConn=new SqlConnection("server=.;
database=pubs;user id=sa;password=;");

SqlDataAdapter adapter=new SqlDataAdapter("select * from authors",sqlConn);

//用来自动生产更新命令

SqlCommandBuilder cb=new SqlCommandBuilder(adapter);

sqlConn.Open();

DataSet ds=new DataSet();

adapter.Fill(ds);

sqlConn.Close();

//处理数据在打开和关闭之后

for (int i=0; i<ds.Tables[0].Rows.Count; i++)

{

for (int j=0; j<ds.Tables[0].Columns.Count; j++

{

Console.Write(ds.Tables[0].Rows[i][j]+" ");

}

Console.WriteLine();

}

//更改数据

ds.Tables[0].Rows[0][1]="A";

ds.Tables[0].Rows[1].Delete();

//更新数据库

sqlConn.Open();

adapter.Update(ds);

sqlConn.Close();