增、修改都没问题，为什么删除不了记录。

Question

  private void button4_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection("Data Source=localhost;Initial Catalog=s1;Integrated Security=SSPI");
            SqlDataAdapter adap = new SqlDataAdapter();
            //float c = float.Parse(textBox5.Text);
            InitSqlDataAdapter(adap, con);
            DataSet ds = new DataSet();
            adap.Fill(ds, "book");
            MessageBox.Show(ds.Tables["book"].Rows.Count.ToString());
            updateDataSource(adap, ds);
            con.Close();        }
        private void InitSqlDataAdapter(SqlDataAdapter adapter, SqlConnection conn)
        {
            SqlCommand cmSel = null;
            cmSel = new SqlCommand("select * from book", conn);
            adapter.SelectCommand = cmSel;            cmSel = new SqlCommand("insert into book(编号,书名,价格)values(@id,@sm,@jg)", conn);
            cmSel.Parameters.Add("@id", SqlDbType.VarChar, 15, "编号");
            cmSel.Parameters.Add("@sm", SqlDbType.VarChar, 15, "书名");
            cmSel.Parameters.Add("@jg", SqlDbType.Money, 15, "价格");
            adapter.InsertCommand = cmSel;            cmSel = new SqlCommand("Update book set 书名=@sm,价格=@jg where 编号=@id", conn);
            cmSel.Parameters.Add("@id", SqlDbType.VarChar, 15, "编号");
            cmSel.Parameters.Add("@sm", SqlDbType.VarChar, 15, "书名");
            cmSel.Parameters.Add("@jg", SqlDbType.Money, 15, "价格");
            adapter.UpdateCommand = cmSel;            cmSel = new SqlCommand("delete from book where 编号=@id", conn);
            cmSel.Parameters.Add("@id", SqlDbType.VarChar, 15, "编号");
            adapter.DeleteCommand= cmSel;
 
        }
        private void  updateDataSource(SqlDataAdapter customers,DataSet decust)
        {
            int de=0;
            for (int i = 0; i < decust.Tables["book"].Rows.Count; i++)
            {
                DataRow dr = decust.Tables["book"].Rows[i];
                if (dr["编号"].ToString() == "002")
                {
                    dr["书名"] = "003";
                    dr["价格"] = 8.9f;
                }                if (dr["编号"].ToString().Trim() =="002")
                {
                    de = i;                    decust.Tables["book"].Rows.RemoveAt(de);
                   
                }  
            }
            dataGridView1.DataSource = decust.Tables[0];
            DataRow ndr = decust.Tables["book"].NewRow();
            ndr["编号"] = textBox3.Text;
            ndr["书名"] = textBox4.Text;
            ndr["价格"] = decimal.Parse(textBox5.Text);
            decust.Tables["book"].Rows.Add(ndr);            customers.Update(decust.Tables["book"]);
        }

Answer 1

cmSel = new SqlCommand("delete from book where 编号=@id", conn);
断点,看sql是什么内容 ID有值吗

Answer 2

cmSel.Parameters.Add(new sqlParameters("@jg", SqlDbType.Money, 15, "价格"));

Answer 3

  decust.Tables["book"].Rows.RemoveAt(de);
不是删除了decust.Tables["book"].Rows然后customers.Update(decust.Tables["book"]);

Answer 4

try catch 一下。  跟踪ID的值

Answer 5

LZ是说dataGridView1中显示的数据没有删除，还是说物理数据库中的数据没有删除？若是前者，请将
customers.Update(decust.Tables["book"]);
这句放到dataGridView1.DataSource = decust.Tables[0];
之前。

Answer 6

DataSet ds = new DataSet();
SqlDataAdapter sda;SqlCommandBuilder scb = new SqlCommandBuilder(sda);
sda.Update(ds);
this.dataGridView1.DataSource = ds.Tables[0];

Answer 7

cmSel = new SqlCommand("delete from book where 编号=@id", conn);
  cmSel.Parameters.Add("@id", SqlDbType.VarChar, 15, "编号");
  adapter.DeleteCommand= cmSel;
跟踪看一下有没有ID传进去，看看SQL语句是什么

Answer 8

          跟踪调试、  看看执行的sql语句  ？ 

Answer 9

跟踪调试、 看看执行的sql语句 ？在查询分析器中看是否可以执行

Answer 10

把 decust.Tables["book"].Rows.RemoveAt(de);
换成  decust.Table["book"].Rows[de].Delete();试一下