ALTER TABLE migration_demo CHANGE type demo_type INT DEFAULT 0 NOT NULL
ALTER TABLE migration_demo CHANGE type type BIGINT DEFAULT 0 NOT NULL
//无效方式2
Schema::table('migration_demo', function (Blueprint $table) {
$table->bigInteger('type')->default('0')->change()->renameColumn('type', 'demo_type');
});
执行语句 ,rename并没有生效
ALTER TABLE migration_demo CHANGE type type BIGINT DEFAULT 0 NOT NULL
同一字段执行多种变更,正确的方式
Schema::table('demo', function (Blueprint $table) {
$table->renameColumn('name', 'demo_name');
});
Schema::table('demo', function (Blueprint $table) {
$table->string('demo_name', 255)->default('')->change();
});
执行语句结果
ALTER TABLE demo CHANGE demo_name demo_name VARCHAR(255) DEFAULT '' NOT NULL COLLATE utf8mb4_unicode_ci
ALTER TABLE demo CHANGE name demo_name VARCHAR(20) DEFAULT '' NOT NULL
traceroute www.58.com
traceroute to www.58.com (211.151.111.30), 30 hops max, 40 byte packets
1 unknown (192.168.2.1) 3.453 ms 3.801 ms 3.937 ms
2 221.6.45.33 (221.6.45.33) 7.768 ms 7.816 ms 7.840 ms
3 221.6.0.233 (221.6.0.233) 13.784 ms 13.827 ms 221.6.9.81 (221.6.9.81) 9.758 ms
4 221.6.2.169 (221.6.2.169) 11.777 ms 122.96.66.13 (122.96.66.13) 34.952 ms 221.6.2.53 (221.6.2.53) 41.372 ms
5 219.158.96.149 (219.158.96.149) 39.167 ms 39.210 ms 39.238 ms
6 123.126.0.194 (123.126.0.194) 37.270 ms 123.126.0.66 (123.126.0.66) 37.163 ms 37.441 ms
7 124.65.57.26 (124.65.57.26) 42.787 ms 42.799 ms 42.809 ms
8 61.148.146.210 (61.148.146.210) 30.176 ms 61.148.154.98 (61.148.154.98) 32.613 ms 32.675 ms
9 202.106.42.102 (202.106.42.102) 44.563 ms 44.600 ms 44.627 ms
10 210.77.139.150 (210.77.139.150) 53.302 ms 53.233 ms 53.032 ms
11 211.151.104.6 (211.151.104.6) 39.585 ms 39.502 ms 39.598 ms
12 211.151.111.30 (211.151.111.30) 35.161 ms 35.938 ms 36.005 ms
Illuminate\Foundation\Bootstrap\LoadEnvironmentVariables;
/**
* Bootstrap the given application.
*
* @param \Illuminate\Contracts\Foundation\Application $app
* @return void
*/
public function bootstrap(Application $app)
{
//此处判断是否开启缓存配置,开启缓存配置直接返回缓存中的配置
//因此开启缓存配置后,env()函数会失效
if ($app->configurationIsCached()) {
return;
}
$this->checkForSpecificEnvironmentFile($app);
//此处加载.env中的文件
try {
(new Dotenv($app->environmentPath(), $app->environmentFile()))->load();
} catch (InvalidPathException $e) {
//
}
}
/**
* Gets the value of an environment variable.
*
* @param string $key
* @param mixed $default
* @return mixed
*/
function env($key, $default = null)
{
$value = getenv($key);
if ($value === false) {
return value($default);
}
switch (strtolower($value)) {
case 'true':
case '(true)':
return true;
case 'false':
case '(false)':
return false;
case 'empty':
case '(empty)':
return '';
case 'null':
case '(null)':
return;
}
if (strlen($value) > 1 && Str::startsWith($value, '"') && Str::endsWith($value, '"')) {
return substr($value, 1, -1);
}
return $value;
}
/**
* Get / set the specified configuration value.
*
* If an array is passed as the key, we will assume you want to set an array of values.
*
* @param array|string $key
* @param mixed $default
* @return mixed|\Illuminate\Config\Repository
*/
function config($key = null, $default = null)
{
if (is_null($key)) {
return app('config');
}
if (is_array($key)) {
return app('config')->set($key);
}
return app('config')->get($key, $default);
}
//app('config) 生成的是 Illuminate\Config\Repository 实例
