使用LIKE对未知（动态）查询数进行Rails SQL查询

Question

I have a Rails search form that performs a dynamic query. That is, the user enters a search like:

(hobby="skiing") OR (gender="male" AND hobby="jogging") 

So, I don't know how many queries I will be searching by until runtime.

I parse the search query by converting it into a valid SQL query, so the above search would be converted to the following format:

query = "hobby LIKE ? OR (gender LIKE ? AND hobby LIKE ?)"
queries = ["skiing", "male", "jogging"]

For the following query:

where(query, queries)

However, the general syntax of the Rails search query is very limiting:

where(query, query_1, query_2, query_3)

I cannot replace the 'query_n' arguments with an array like I want to, without Rails throwing an error.

NoMethodError (undefined method `where' for ["a", "b", "c"]:Array)

Attempting to splat the array yields the same error:

where(query, *queries)

Again:

NoMethodError (undefined method `where' for ["a", "b", "c"]:Array)

So what can I do?

EDIT:

The full search function looks like this:

def self.search(search)
    query = "%#{search}%"
    if search
        includes(:games, :jobs)
        strngs = ["hobby = ? OR name = ? OR gender = ?", "dsfgdsfg", "dsgsdfgsd", "sdfsfsdf"]
        .where(strngs)

Answer 1

What you'll want to do is pass an array as a single argument to where which contains both the query AND the dynamic values. For example:

where(["att_1 LIKE ? OR att_2 LIKE ?", "value1", "value2"])

If an array is passed as the first and only argument, then the first element of the array is treated as a template. The following array values are treated as the dynamic values for the query template.

For your example, instead of having two separate variables queries and query , combine them into one query variable:

# A single array with the query AND values
query = ["hobby LIKE ? OR (gender LIKE ? AND hobby LIKE ?)", "skiing", "male", "jogging"]

# Run the `where` with a single array as the argument
YourModel.where(query)

This will allow you to query the DB with an unknown number of values using LIKE .

For reference: Rails where() docs