C#中的SQL数据库操作

//单字段查询
SqlConnection conn = new SqlConnection(strConnection));
conn.Open();
SqlCommand command=new SqlCommand(“SQL查询语句”,conn);
int num=(int)command.ExecuteScalar();
conn.Close();

//字段更新
SqlConnection conn = new SqlConnection(strConnection));
conn.Open();
SqlCommand command=new SqlCommand(/“SQL更新语句”,conn);
command.ExecuteNonQuery();
conn.Close();

读取多条数据
SqlDataReader dr = comm.ExecuteReader(CommandBehavior.CloseConnection);//,SqlDataReader 对象被关闭时连接自动关闭
while(dr.Read()){
dr["索引或列名"]；//具体操作略
}
dr.Close();

//表操作
SqlConnection conn = new SqlConnection(strConnection));
DataSet ds=new DataSet();
SqlDataAdapter myAdapter = new SqlDataAdapter();//new一个adapter对象
myAdapter.Fill(ds);
SqlCommandBuilder myCommandBuilder = new SqlCommandBulider();//new一个Bulider对象
myAdapter.InsertCommand = myCommandBuilder .GetInsertCommand();//插入
myAdapter.UpdateCommand = myCommandBuilder .GetUpdateCommand();//更新
myAdapter.DeleteCommand = myCommandBuilder .GetDeleteCommand();//删除
conn.Open();
myAdapter.Update(ds); //更新ds到数据库
conn.Close();