dataGridView5.Rows[dataGridView5.CurrentCell.RowIndex].Selected = true;
            SqlConnection thisConnection = new SqlConnection(@"Server=.;database=mystudent;Integrated Security=true;");          //连接数据库
            SqlDataAdapter thisAdapter = new SqlDataAdapter("SELECT * FROM TABLE1 order by 学号 asc", thisConnection);                  //将查询字符串与连接适配
            SqlCommandBuilder thisBuilder = new SqlCommandBuilder(thisAdapter);
            DataSet thisDataSet = new DataSet();                  //定义一个DataSet
            thisAdapter.Fill(thisDataSet, "TABLE1");              //将TABLE1填充到DataSet
            for(int j=0;j<thisDataSet.Tables["TABLE1"].Rows.Count;j++)
            {
                for (int i = 0; i < 5; i++)
                {
                    if (!thisDataSet.Tables["TABLE1"].Rows[j][i].ToString().Trim().Equals(this.dataGridView1.CurrentRow.Cells[this.dataGridView1.CurrentCell.ColumnIndex].Value.ToString().Trim()))
                    {
                        thisDataSet.Tables["TABLE1"].Rows[j][i]= this.dataGridView5.CurrentRow.Cells[i].Value.ToString().Trim();
                    }
                }
            }
                thisAdapter.Update(thisDataSet, "TABLE1");




就看if那里，我跟踪了，每次都执行if里面的赋值语句，本意是想如果dgv里改动的值和ds里表的值不相等时，就赋值给ds对应的单元格，然后更新，不想if语句竟不起效果

我前面没说清楚这比较要做什么，不好意思哈
现在搞定了

就是dgv里的改动单元格和ds里的表进行比较，如果不相等
就把dgv改动的值赋给ds对应的单元格