我有以下迁移：

public function up() {
    Schema::create('configurations', function (Blueprint $table) {
        $table->increments('id');
        $table->string('name')->unique();
        $table->json('config');
        $table->timestamps();
        $table->timestamp('deleted_at')->nullable();
    });

    DB::unprepared('
        CREATE TRIGGER configuration_no_update_name BEFORE UPDATE ON configurations 
        FOR EACH ROW BEGIN
            IF OLD.name <=> NEW.name THEN
                SIGNAL SQLSTATE \'45000\'
                    SET MESSAGE_TEXT = \'Cannot update Configuration name\';
            END IF;
        END;
    ');
}

public function down() {
    Schema::dropIfExists('connection_configs');
    DB::unprepared('DROP TRIGGER IF EXISTS configuration_no_update_name');
}

播种机：

public function run() {
    $data = [
        [
            'name' => 'System A',
            'config' => json_encode([
                'host' => '127.0.0.1:80',
                'grant_type' => 'password',
                'token' => '',
                'username' => 'testUser',
                'password' => 'test',
            ]),
            'created_at' => Carbon::now(),
            'updated_at' => Carbon::now(),
        ],
    ];

    DB::table('configurations')->insert($data);
}

在mysql中，我启用了日志：

SET GLOBAL log_output = 'FILE';
SET GLOBAL general_log_file = '/tmp/my_logs.txt';
SET GLOBAL general_log = 'ON';

的结果 SELECT * FROM configurations; ```
| 1 | System A | {"host": "127.0.0.1:80", "token": "", "password": "test", "username": "testUser", "grant_type": "password"} | 2018-01-12 09:03:14 | 2018-01-12 09:03:14 | NULL |

问题出在触发器上。
触发器背后的想法是阻止对 `name` 现场。
但是当我第一次测试触发器时，更新不会被阻止，但是当我再次运行它时，它会被阻止： `UPDATE configurations SET name = 'Some System' WHERE id = 1;` （2次）
输出：
![](https://i.stack.imgur.com/YOtTv.png)
日志：

2018-01-12T09:26:30.406449Z 31 Query UPDATE configurations SET name = 'Some System' WHERE id = 1
2018-01-12T09:26:35.430263Z 31 Query UPDATE configurations SET name = 'Some System' WHERE id = 1
2018-01-12T09:26:35.430465Z 31 Query SIGNAL SQLSTATE '45000'
SET MESSAGE_TEXT = 'Cannot update Configuration name'

之后，我试着用 `Laravel` 要更新字段：

$c = Configuration::first();
$c->name = 'Some other system';
$c->save();

输出：

2018-01-12T09:34:39.292290Z 56 Connect root@127.0.0.1 on system_db using TCP/IP
2018-01-12T09:34:39.293006Z 56 Query use system_db
2018-01-12T09:34:39.293510Z 56 Prepare set names 'utf8mb4' collate 'utf8mb4_unicode_ci'
2018-01-12T09:34:39.293862Z 56 Execute set names 'utf8mb4' collate 'utf8mb4_unicode_ci'
2018-01-12T09:34:39.294312Z 56 Close stmt
2018-01-12T09:34:39.294416Z 56 Prepare set session sql_mode='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'
2018-01-12T09:34:39.294802Z 56 Execute set session sql_mode='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'
2018-01-12T09:34:39.295227Z 56 Close stmt
2018-01-12T09:34:39.295493Z 56 Prepare select * from configurations where configurations.deleted_at is null limit 1
2018-01-12T09:34:39.300104Z 56 Execute select * from configurations where configurations.deleted_at is null limit 1
2018-01-12T09:34:39.300791Z 56 Close stmt
2018-01-12T09:34:39.367476Z 56 Prepare update configurations set name = ?, updated_at = ? where id = ?
2018-01-12T09:34:39.367935Z 56 Execute update configurations set name = 'Some other system', updated_at = '2018-01-12 09:34:39' where id = 1
2018-01-12T09:34:39.370971Z 56 Close stmt
2018-01-12T09:34:39.372737Z 56 Quit

结果：条目的名称更改为 `Some other system` 我真搞不懂它为什么会这样。如果有其他替代方法 `name` 字段不变那就太好了