public List<Product> findByIddd(String guess) { Connection conn = null; PreparedStatement pstmt = null; ResultSet rs = null; List<Product> products = new ArrayList<>(); try { conn = DBHelper.getConnection(); String sql = "select productid, category, cname, ename, image, " + "listprice, unitcost, descn " + "from products where productid = ? "; pstmt = conn.prepareStatement(sql); pstmt.setString(1, guess); rs = pstmt.executeQuery(); while (rs.next()) { Product p = new Product(); p.setProductid(rs.getString("productid")); p.setCategory(rs.getString("category")); p.setCname(rs.getString("cname")); p.setEname(rs.getString("ename")); p.setImage(rs.getString("image")); p.setListprice(rs.getDouble("listprice")); p.setUnitcost(rs.getDouble("unitcost")); p.setDescn(rs.getString("descn")); products.add(p); } } catch (SQLException e) { e.printStackTrace(); } finally { if (rs != null) { try { rs.close(); } catch (SQLException e) { } } if (pstmt != null) { try { pstmt.close(); } catch (SQLException e) { } } if (conn != null) { try { conn.close(); } catch (SQLException e) { } } } return products; }改成返回输出所有包含guess关键字的数据要怎么改

要查询所有包含 `guess` 关键字的数据，可以将 SQL 语句中的 `where` 子句改为使用 `like` 操作符进行模糊匹配。具体的改动如下所示：

public List<Product> findByIddd(String guess) {
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    List<Product> products = new ArrayList<>();
    try {
        conn = DBHelper.getConnection();
        String sql = "select productid, category, cname, ename, image, " +
                     "listprice, unitcost, descn " +
                     "from products " +
                     "where cname like ? or ename like ?"; // 改动的语句
        pstmt = conn.prepareStatement(sql);
        pstmt.setString(1, "%" + guess + "%"); // 模糊匹配
        pstmt.setString(2, "%" + guess + "%"); // 模糊匹配
        rs = pstmt.executeQuery();
        while (rs.next()) {
            Product p = new Product();
            p.setProductid(rs.getString("productid"));
            p.setCategory(rs.getString("category"));
            p.setCname(rs.getString("cname"));
            p.setEname(rs.getString("ename"));
            p.setImage(rs.getString("image"));
            p.setListprice(rs.getDouble("listprice"));
            p.setUnitcost(rs.getDouble("unitcost"));
            p.setDescn(rs.getString("descn"));
            products.add(p);
        }
    } catch (SQLException e) {
        e.printStackTrace();
    } finally {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
            }
        }
        if (pstmt != null) {
            try {
                pstmt.close();
            } catch (SQLException e) {
            }
        }
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
            }
        }
    }
    return products;
}

这样修改后，该方法会查询出所有包含 `guess` 关键字的数据，无论是在 `cname` 列还是在 `ename` 列中出现的。