如何在字符串属性中搜索id（SQL）(How do I search an id in a string attribute (SQL))

 在我的聊天应用程序中，我想计算学生模型的响应率。 
 
 我使用slug属性跟踪所有会话。 这是一个像这样的字符串： 270-77 ，这意味着这是学生270和招聘人员77之间的对话。 
 
 现在我想查看一个学生的谈话次数。 这是我的代码： 
 
def calculate_number_of_conversations(@student)
  @conversations = Conversation.where("slug LIKE ?", "%#{params[@student]}")
end
 
 重要的是它应该只搜索字符串的第一部分，因为slug的第一个数字始终是学生的id。 

In my chat app I want to calculate the response rate for student model.
 
I track all conversations with a slug attribute. It's a string like this: 270-77, which means that this is a conversation between student 270 and recruiter 77. 
 
Now I want to check how many conversations one student has. Here is my code:
 
def calculate_number_of_conversations(@student)
  @conversations = Conversation.where("slug LIKE ?", "%#{params[@student]}")
end
 
Important is that it should only search in the first part of the string because the first number in slug is always a student's id.

原文：https://stackoverflow.com/questions/46001727