java - 我无法删除 mysql 表中的所有行

Question

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

我在 java 中使用这段代码:

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());
        }

但是这段代码总是只从表“kosik”中删除一条记录。我想知道如何删除该表中的所有记录。

谁能告诉我我做错了什么？我将不胜感激。

谢谢。

Answer 1

从 SELECT 中删除 LIMIT 1，这样您就可以显示所有记录，而不仅仅是 1。在这一行:

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");

去掉限制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");

不要从 DELETE 中删除 WHERE 否则您将选择 1 条记录 (stmt)，将其插入另一个表 (stmt2) 然后清除所有表，然后将所有其他记录插入 obj_zoznam (stmt3)。