调试h2数据库

生命中的全部偶然，其实都是命中注定。是为宿命。——《宿命》

在apache-shenyu中也默认用h2数据库作为默认数据库，方便开发、演示、学习、轻量化部署等

但是我们知道h2数据库是基于内存的嵌入式数据库，如何让其在运行动态执行sql呢？一般我们采用h2-console进行：

h2-console | 阿超

今天我们换一种方式，直接使用客户端工具连接，默认的url肯定是连不上的：

spring:
  datasource:
    url: jdbc:h2:mem:${HOME:${HOMEDRIVE}${HOMEPATH}}/shenyu;DB_CLOSE_DELAY=-1;MODE=MySQL;
    username: sa
    password: sa
    driver-class-name: org.h2.Driver

因为这里是h2:mem:路径，即便换成file也是不允许两个连接的

我们换成tcp连接，再指定一下目录

spring:
  datasource:
    url: jdbc:h2:tcp://localhost/${HOME:${HOMEDRIVE}${HOMEPATH}}/Downloads/shenyu-study/shenyu;DB_CLOSE_DELAY=-1;MODE=MySQL;SCHEMA=PUBLIC;
    username: sa
    password: sa
    driver-class-name: org.h2.Driver

然后在springboot启动类添加：

import org.h2.tools.Server;

public class H2Server {

    public static void main(String[] args) throws Exception {
        Server server = Server.createTcpServer("-tcpAllowOthers").start();
        System.out.println("H2 server started and connection is open.");
        System.out.println("URL: jdbc:h2:" + server.getURL() + "/~/Downloads/shenyu-dubbo-study/shenyu");
    }
}

例如：

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.shenyu.admin;

import org.h2.tools.Server;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.ldap.LdapAutoConfiguration;

import java.sql.SQLException;

/**
 * shenyu admin start.
 */
@SpringBootApplication(exclude = {LdapAutoConfiguration.class})
public class ShenyuAdminBootstrap {

    /**
     * Main entrance.
     *
     * @param args startup arguments
     */
    public static void main(final String[] args) throws SQLException {
        Server server = Server.createTcpServer("-tcpAllowOthers").start();
        System.out.println("H2 server started and connection is open.");
        System.out.println("URL: jdbc:h2:" + server.getURL() + "/~/shenyu");
        SpringApplication.run(ShenyuAdminBootstrap.class, args);
    }

}

然后启动项目以后你就可以用客户端工具连接啦：

url选择：jdbc:h2:tcp://localhost/~/Downloads/shenyu-study/shenyu

用户名和密码都还是sa，快乐调SQL吧～

对了，这里需要先初始化数据库到该目录，可以先这么连接：

spring:
  datasource:
    url: jdbc:h2:tcp://localhost/~/Downloads/shenyu-study/shenyu;DB_CLOSE_DELAY=-1;MODE=MySQL;SCHEMA=PUBLIC;
    username: sa
    password: sa
    driver-class-name: org.h2.Driver

由于我们指定了目录，因此会在目录下初始化数据库