我已经创建了一个模块来验证针对不同数据库的凭据。define_method("#{database}_connect") do |args| when 'mysql' then Mysql2::Client.new args.merge(ssl_mode: :disabled)
when 'mssql' then
Mysql查询:FROM `pet_info` LEFT JOIN ON `pet_info`.`id` = `lostpets`.`petid` WHEN `pet_info`.pet_user_id` = 581You have an error in your SQL syntax; check the manual that corresponds
执行SQL时没有问题。问题是,结果是如何将所有课程按一行对每个人进行分组?或者SQL是如何逐步执行的?(select 'o' from Courses where name = c.name and course = 'SQL')as SQL,(select 'o' from Courses where name = c.name and