Question

UPDATE语句应该如何包含多个列，那个必须更新？（因为一行已经改变了很多内容）

我在这个主板上尝试了一些搜索，但在其他问题中，有时候“[]”围绕着列，有时候没有，但两个版本在我的代码中都不起作用。

这是代码：

            try 
            {
                string name = mtb_Name.Text.ToString();
                string altname = mtb_AltName.Text.ToString();
                string licht = cb_Licht.SelectedItem.ToString();
                string boden = cb_Boden.SelectedItem.ToString();
                string haerte = cb_Haerte.SelectedItem.ToString();
                string pg = cb_PG.SelectedItem.ToString();
                string hoehe = mtb_Hoehe.Text.ToString();
                string form = cb_Form.SelectedItem.ToString();
                string zuechter = cb_Zuechter.SelectedItem.ToString();
                string land = cb_Land.SelectedItem.ToString();
                string gruppe = cb_Gruppe.SelectedItem.ToString();

//the connection works, I can add stuff in other tables and delete stuff everywhere

                parent.GetDBConnection().Open();
                OleDbCommand Query = new OleDbCommand();
                Query.Connection = parent.GetDBConnection();
                Query.Parameters.Clear();

//I build this string at the moment for testing purposes only and 
//converted everything and putted in a string to be sure.
//later it will be replaced with the Parameters.Add(,)
//I also did test it with [AltNameRose] as columname instead of AltNameRose
//or wrote instead of the ' ' a "\"" around the strings, 
//but doesn´t seem to be the problem.

                Query.CommandText = "UPDATE tb_Rose SET" +
                    " ,AltNameRose = '" + altname +
                    "' ,NameZuechter = '" + haerte +
                    "' ,Boden = '" + boden +
                    "' ,Wuchshoehe = '" + hoehe +
                    "' ,Farbe = '" + " " +
                    "' ,Foto = '" + " " +
                    "' ,Licht = '" + licht +
                    "' ,Preisgruppe = '" + pg +
                    "' ,Gruppe = '" + gruppe +
                    " WHERE NameRose = '" + name + "'";

//the CommandText seems to be missing something, but I don´t know what.

                MessageBox.Show(Query.CommandText.ToString());
                Query.ExecuteNonQuery();
                parent.GetDBConnection().Close();
                MessageBox.Show("Rose successfully edited.");
                this.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                parent.GetDBConnection().Close();
            }

抛出的异常是

UPDATE-Command中的语法错误

表tb_Rose看起来像这样： NameRose | AltNameRose | NameZuechter | Frosthaerte |博登| Wuchshoehe | FARBE |图片|| Licht的| Preisgruppe | GRUPPE

另一个问题是，订单，我如何通过列也很重要，但这对我没用。

有人提出错误的小提示吗？

Answer 1

在第一列之前，您不需要使用逗号。这就是你的原因;

" ,AltNameRose = '"

应该是

" AltNameRose = '"

但更重要的是，您应该始终使用parameterized queries。这种字符串连接对SQL Injection攻击开放。

还可以使用using statement自动处理您的连接和命令，而不是手动调用.Close()方法。

Answer 2

Update语句的语法是

Update table_name SET
                  column_name = value,
                  column_name = value,
                  ....
                  Where condition

在您的查询中，您在SET关键字后面添加了,。

在SET关键字后面有, ..尝试下面的代码

Query.CommandText = "UPDATE tb_Rose SET" +
                    " AltNameRose = '" + altname +
                    "' ,NameZuechter = '" + haerte +
                    "' ,Boden = '" + boden +
                    "' ,Wuchshoehe = '" + hoehe +
                    "' ,Farbe = '" + " " +
                    "' ,Foto = '" + " " +
                    "' ,Licht = '" + licht +
                    "' ,Preisgruppe = '" + pg +
                    "' ,Gruppe = '" + gruppe +
                    " WHERE NameRose = '" + name + "'";

C＃如何更新访问表

2 个答案: