mysql - Rails 3. 在 SQL 中检查真值

Question

我需要检查 exam 列的值是否为 true。所以我设置了它，但它不起作用...

@exam_shipments = Shipment.where("exam <> NULL AND exam <> 0 AND customer_id = ?", current_admin_user.customer_id)

# This one gives me error "SQLite3::SQLException: no such column: true:"
@exam_shipments = Shipment.where("exam = true AND customer_id = ?", current_admin_user.customer_id) 

@exam_shipments = Shipment.where("exam = 1 AND customer_id = ?", current_admin_user.customer_id)

Answer 1

你真的应该坚持使用 AR 语法:

@exam_shipments = Shipment.where(:exam => true, :customer_id => current_admin_user.customer_id)

假设 :exam 是您的 Shipment 模型中的 bool 字段。 ActiveRecord 负责将您的查询转换为给定数据库的正确语法。因此，您编写的内联 SQL 越少，您的代码就越能与数据库无关并可移植。