sql - rails SQL : Creating a query dynamically

Question

我正在尝试根据用户输入创建动态查询

if a
  conditions << ["fname like (?)"]
  sql_params <<  "abc"
end
if b
  conditions << ["lname like (?)"]  
  sql_params <<  "def"  
end
if c
  cconditions << ["middle like (?)"]  
  sql_params <<  "xyz"   
end

results = Model.where(conditions.join(' AND '), sql_params)

虽然条件语法正确，但 sql_params 被列为数组。这形成了下面的查询

Model.where("fname like (?) AND lname like (?) AND middle like (?)", ["abc","def","xyz"])

我需要的是

Model.where("fname like (?) AND lname like (?) AND middle like (?)", "abc","def","xyz")

我在 sql_params 数组上尝试了几个 map/join 等选项，但没有任何效果。

Answer 1

您确定要生产这个吗？

Model.where("fname like (?) AND lname like (?) AND middle like (?)", "abc","def","xyz")

形式的东西:

Model.where('expr1 AND expr2 AND expr3')

相当于:

Model.where('expr1').where('expr2').where('expr3')

那么为什么不逐个构建查询而不是乱用字符串呢？像这样:

query = Model.all
query = query.where('fname  like ?', 'abc') if a
query = query.where('lname  like ?', 'def') if b
query = query.where('middle like ?', 'xyz') if c

会给你同样的结果。