Question

您好，我想删除mysql表中名为“ kosik”的所有行，并将它们传递给另一个名为“ obj_zoznam”的表。

我在Java中使用以下代码：

String orderstatus = "Accepted";
        try {
            stmt = con.createStatement();
            stmt2 = con.createStatement();
            stmt3 = con.createStatement();

            rs = stmt.executeQuery("select ID as idzaz, ID_pouzivatela as idpou, ID_tovaru as idtov, cena as suma, ks as kusy from kosik order by ID limit 1");

            while (rs.next()) {

                int zaz = rs.getInt("idzaz");
                int pou = rs.getInt("idpou");
                int tov = rs.getInt("idtov");
                int suma = rs.getInt("suma");
                int kusy = rs.getInt("kusy");

                String sstr = "insert into obj_zoznam (ID_pouzivatela, ID_tovaru, suma, ks, stav) values ("
                        + "'" + id_usera + "', "
                        + "'" + tov + "', "
                        + "'" + suma + "', "
                        + "'" + kusy + "', "
                        + "'" + orderstatus + "')";

                String sstr2 = "delete from kosik where ID = " + zaz;

                stmt2.executeUpdate(sstr);
                stmt3.executeUpdate(sstr2);
            }

            stmt.close();
            stmt2.close();
            stmt3.close();
        } catch (Exception e) {
            out.println("Error in writing: " + e.toString());
        }

但是，此代码始终仅从表“ kosik”中删除一条记录。我试图弄清楚如何删除此表中的所有记录。

谁能告诉我我在做什么错？我将非常感谢。

谢谢。

Answer 1

我试图弄清楚如何删除此表中的所有记录。

然后从您的where语句中删除该过滤条件delete

delete from kosik

Answer 2

从LIMIT 1中删除SELECT，以便显示所有记录，而不仅仅是1条记录。

rs = stmt.executeQuery("select ID as idzaz, ID_pouzivatela as idpou, ID_tovaru as idtov, cena as suma, ks as kusy from kosik order by ID limit 1");

删除限制1：

rs = stmt.executeQuery("select ID as idzaz, ID_pouzivatela as idpou, ID_tovaru as idtov, cena as suma, ks as kusy from kosik order by ID");

请勿从WHERE中删除DELETE，否则您将选择1条记录（stmt），将其插入另一张表（stmt2）中，然后清除所有记录将该表插入obj_zoznam（stmt3）中之前。

Answer 3

您将查询的结果限制为一行，因此您始终只有一个ID。 sstr2的执行将始终删除具有第一个id的记录

Answer 4

如果要删除保留表结构的条目，则应使用truncate命令。

truncate table kosik

我无法删除mysql表中的所有行

4 个答案: