是否有办法使数据在Laravel迁移?我找到了一些关于如何播种数据库的说明，但它没有涵盖我需要将一个字段拆分为多个字段或将多个字段合并为一个的情况。
一个可能的解决方案是查询数据库并在循环中更新每个记录。这种方法的问题是，模型在迁移过程中可能无法反映表的模式(Django为此提供了一个解决方案)。
Laravel有内置的迁移功能:)http://laravel.com/docs/migrations
运行> 它将在app/database/migrations下创建一个迁移。然后你可以在up()和down()方法中使用Laravel的数据库类。
让我们以这个为例…
class SplitColumn extends Migration {
/**
* Run the migrations.
*
* @return void
*/
public function up()
{
Schema::table('table_name', function($table)
{
// Create new columns for table_name (1 column split into 2).
$table->string('new_column');
$table->string('new_column_b');
});
// Get records from old column.
$results = DB::table('table_name')->select('old_column')->get();
// Loop through the results of the old column, split the values.
// For example, let's say you have to explode a |.
foreach($results as $result)
{
$split_value = explode("|", $result->old_column);
// Insert the split values into new columns.
DB::table('table_name')->insert([
"new_column" => $split_value[0],
"new_column_b" => $split_value[1]
]);
}
// Delete old column.
Schema::table('table_name', function($table)
{
$table->dropColumn('old_column');
});
}
/**
* Reverse the migrations.
*
* @return void
*/
public function down()
{
Schema::table('table_name', function($table)
{
// Re-create the old column.
$table->string('old_column');
});
// Get records from old column.
$results = DB::table('table_name')->select('new_column', 'new_column_b')->get();
// Loop through the results of the new columns and merge them.
foreach($results as $result)
{
$merged_value = implode("|", [$result->new_column, $result->new_column_b]);
// Insert the split values into re-made old column.
DB::table('table_name')->insert([
"old_column" => $merged_value
]);
}
// Delete new columns.
Schema::table('table_name', function($table)
{
$table->dropColumn('new_column');
$table->dropColumn('new_column_b');
});
}
}