如何将datagrid中的数据保存到数据库

用SQL的插入语句 先写一个公共类
public SqlConnection Connection(string str_sql)
{
string str = "server=.;user id=sa;password='';database=学生管理系统";
SqlConnection sql_conn = new SqlConnection(str);
return sql_conn;
}

public DataTable SelectDataBySql(string str_sql)
{
SqlConnection sql_conn = Connection(str_sql);
SqlDataAdapter Adapter = new SqlDataAdapter(str_sql,sql_conn);
DataSet ds = new DataSet();
Adapter.Fill(ds);
return ds.Tables[0];
}
public int InsertDataBySql(string str_sql)
{
SqlConnection conn = Connection(str_sql);
SqlCommand Command = new SqlCommand();
Command.Connection = conn;
Command.CommandType = CommandType.Text;
Command.CommandText = str_sql;