Rails 4：MySQL 2错误

Question

我已经将项目升级到Rails 4，但是Mysql出现错误：

Mysql2::Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '=> nil OR delete_by < 1)) ORDER BY Mysql2::Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '=> nil OR delete_by < 1)) ORDER BY t_dest_boards . 第ASC LIMIT 1' at line 1: SELECT id ASC LIMIT 1' at line 1: SELECT t_dest_boards中ASC LIMIT 1' at line 1: SELECT .* FROM WHERE (m_section_id = 1 AND v_employee_id = '02001' AND registration_date = '2017-02-13' AND (delete_by => nil OR delete_by < 1)) ORDER BY t_dest_boards . id ASC LIMIT 1

在这行代码中：

tdest_tmp = TDestBoard.where("m_section_id = ? AND v_employee_id = ? AND registration_date = ? AND (delete_by => nil OR delete_by < ?)", primary_section.m_section_id, params[:id], params[:tdaily_dates]["#{id}"], 1).first

在Rails 4中执行此操作的正确方法是什么？ 提前致谢！

Answer 1

delete_by => nil可能是引发错误的代码。 如果要检查字段是否为零，请在条件中使用“ IS NULL”。 因此，如下更改代码

tdest_tmp = TDestBoard.where("m_section_id = ? AND v_employee_id = ? AND registration_date = ? AND (delete_by IS NULL OR delete_by < ?)", primary_section.m_section_id, params[:id], params[:tdaily_dates]["#{id}"], 1).first