配置好entity后，编写anotation注释，来声明‘元数据’（metadata）的参数
然后输入执行映射命令行时，出现了以下错误信息

PS D:\symfony_project\my_project_name> php bin/console doctrine:schema:validate
[Mapping]  OK - The mapping files are correct.

In AbstractPlatform.php line 423:

  Unknown database type enum requested, Doctrine\DBAL\Platforms\MySQL57Platform may not support it.


doctrine:schema:validate [--skip-mapping] [--skip-sync] [--em [EM]] [-h|--help] [-q|--quiet] [-v|vv|vvv|--verbose] [-V|--version] [--ansi] [--no-ansi] [-n|--no-interaction] [-e|--env ENV] [--no-debug] [--] <command>

百度了一轮，终于找到解决办法
可以再config.yml里面修改配置

本来config.yml中Doctrine的配置

# Doctrine Configuration
doctrine:
    dbal:
        driver: pdo_mysql
        host: '%database_host%'
        port: '%database_port%'
        dbname: '%database_name%'
        user: '%database_user%'
        password: '%database_password%'
        charset: UTF8
        # if using pdo_sqlite as your database driver:
        #   1. add the path in parameters.yml
        #     e.g. database_path: '%kernel.project_dir%/var/data/data.sqlite'
        #   2. Uncomment database_path in parameters.yml.dist
        #   3. Uncomment next line:
        #path: '%database_path%'
    orm:
        auto_generate_proxy_classes: '%kernel.debug%'
        naming_strategy: doctrine.orm.naming_strategy.underscore
        auto_mapping: true

修改后的配置如下：

# Doctrine Configuration
doctrine:
    dbal:
        driver: pdo_mysql
        host: '%database_host%'
        port: '%database_port%'
        dbname: '%database_name%'
        user: '%database_user%'
        password: '%database_password%'
        charset: UTF8
        # if using pdo_sqlite as your database driver:
        #   1. add the path in parameters.yml
        #     e.g. database_path: '%kernel.project_dir%/var/data/data.sqlite'
        #   2. Uncomment database_path in parameters.yml.dist
        #   3. Uncomment next line:
        #path: '%database_path%'
        mapping_types:
            enum: string
            set: string
            varbinary: string
            tinyblob: text
    orm:
        auto_generate_proxy_classes: '%kernel.debug%'
        naming_strategy: doctrine.orm.naming_strategy.underscore
        auto_mapping: true

以后碰到相同问题，把不支持的几个类型 enum,set等等换成 mysql常用的基本类型 就好了

参考博文：原 SF2 : doctrine 报错处理办法: Unknown database type enum requested
原创文章：doctrine 报错处理办法: Unknown database type enum requested