How to "search" with a string of values for records whose columns contain said values - sql

Question

Okay, I'm going to try to explain this as simply as I can.
Say I have 3 records of a certain table. We will call this table Objs, and Objs have an attribute, of type string, called colors (notice how it's plural). Here are the 3 hypothetical records in the database and their corresponding colors values:
obj1 colors: "red, green, blue"
obj2 colors: "blue, orange, yellow, green"
obj3 colors: "teal, purple"
Okay, so now say I want to be able find a subset of the records that have something in common (a good situation to use the WHERE method right?) However, I HAVE to be able to support searching for these records using either single or even multiple values. For instance:
Say my query is, "red, green".
Then the resulting collection of records would need to be obj1, and obj2 since their color values include the keywords "red" and "green".
Say my query is, "blue, purple".
The resulting collection should include obj1, obj2, and obj3.
Also, the format of the query and the attributes of Obj will be the values delimited with a ", " since the attributes and the query itself are generated by an array. I.e., the attributes of the object and the queries themselves will always have this format:
"value1, value2, value3, value4"
It will never be like this:
"value1 value2 value3 value4"
or any other possible format.
Thanks for all the help.

Answer 1

You could compare the value, treating it as an array, against another array. For example:
SELECT *
FROM example
WHERE string_to_array(colors,', ') && array['red','blue'];
The && operator here checks for overlaps.
Disclosure: I am an EnterpriseDB (EDB) employee.

Answer 2

Let's wrap it into function,
first of all we are creating array from search string to know how many or queries we need,
then we are preparing query,
and as a final step we are passing our query and search words to our model
def search_function(search_string)
names_array = search_string.split(', ')
query = 'name LIKE ?'
number_of_ors = names_array.count
number_of_ors.times do
query += ' OR name LIKE ?'
end
Objects.where(query, *names_array)
end