我在MySQL数据库里有一些表。我正在实现一个Spring Boot应用程序,现在正在测试数据库。我有@Entities:
public class Author implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int id;
...
public class Publisher implements Serializable {
在php中,我有:
$result = mysql_query($query);
// if successful query, return the records
if ($result)
{
// if not empty result, return array of records
if (mysql_num_rows($result))
{
$records = array();
while ($row = mysql_fetch_assoc($result))
{
$records[]
大家好。
我正在想办法对付Hibernate。在我的测试中,我使用Hibernate继承,这是我得到的异常:
Hibernate: select theuser0_.ID as ID1_2_0_, theuser0_.FIRST_NAME as FIRST_NA3_2_0_, theuser0_.LAST_NAME as LAST_NAM4_2_0_, theuser0_.PASSWORD as PASSWORD5_2_0_, theuser0_.EMALE as EMALE6_2_0_, theuser0_.GENDER as GENDER7_2_0_, theuser0_.UCI_PERS
从Oracle迁移到MySQL,我们发现了许多不兼容的问题。我们有很多解决办法,但是我们仍然有一个:序列
我们有这张桌子
CREATE TABLE "HEADS"(
"HEAD_ID" NUMBER NOT NULL ENABLE,
"COLUMN" NUMBER NOT NULL ENABLE,
"ROW" NUMBER NOT NULL ENABLE,
"VALUE" VARCHAR2(200),
"CREATED_BY" VARCHAR2(40),
有人能给我解释一下吗?
mysql> select * from heartbeat order by id desc limit 20;
+---------+---------------------+---------------------------------------------------------+
| id | date | node |
+---------+----------------
我有以下实体
/*
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* and open the template in the editor.
*/
package com.travelagency.travelagencybackend.entities;
import java.io.Serializable;
import javax.persis
我有一个从MySQL数据库填充的可变大小(长度)的表单。有4个字段组成了用于创建按钮的信息(id、button#、name和price)。提交表单时,我希望将所有值保存到div db中,并使用成功消息更新页面底部的MySQl。目前我有这个表格。
<?php include("./db/db_connect.php"); ?>
<form method="POST" action="fixcon.php">
<?php
$sql = "SELECT * FROM concessions ORDER BY but
如果列定义中的NOT NULL同时具有PRIMARY KEY和AUTO_INCREMENT,为什么该列不能工作?在MySQL 5.6上测试。
CREATE TABLE test (
id INT NOT NULL AUTO_INCREMENT PRIMARY KEY
);
INSERT INTO test VALUES (NULL);
SELECT * FROM test;
结果:
id
1