CODEWITHSUNDEEP
mysqlarraysrubydatabase
Bijendra
Bijendra

Reputation: 10043

Ruby methods on array to have separate elements

I'm writing a ruby script and looking to execute the native Sql queries.

I/p       arr = ["1", 2, "3", 5, 6]

Expected o/p:

arr = (1,2,3,4)

It has to be something simple which i'm missing, join always gives me "(1,2,3,4)" which when used in query like 

 select * from users where id IN (1,2,3,4)

should work. Currently when "(1,2,3,4)" is used as input, only id is matched with is 1.

EDIT:

I'm using mysql.

require 'mysql2'

client = Mysql2::Client.new(:host => @db_host, :username => @db_user, :password => @db_pass, :database => @db_name, :port => @port)

Any quick solution will be of help

Upvotes: 0

Views: 39

Answers (2)

Kris
Kris

Reputation: 19948

 inp = ["1", 2, "3", 5, 6]
 outp = "(#{inp.join(',')})"
 # => "(1,2,3,5,6)"

Upvotes: 1

marmeladze
marmeladze

Reputation: 6572

Use Array#join.

here is my sample table

$ sqlite3 test.db
SQLite version 3.11.0 2016-02-15 17:29:24
Enter ".help" for usage hints.
sqlite> select * from cars;
1|Audi|52642
2|Mercedes|57127
3|Skoda|9000
4|Volvo|29000
5|Bentley|350000
6|Citroen|21000
7|Hummer|41400
8|Volkswagen|21600

below code shows how to query (this is almost same in mysql/postgres etc.) with in clause given an array. 

$ irb
2.3.1 :001 > require 'sqlite3'
# => true 
2.3.1 :002 > db = SQLite3::Database.open 'test.db'
# => #<SQLite3::Database:0x00000000d892d0 @tracefunc=nil, @authorizer=nil, ... 
2.3.1 :003 > qry = "select * from Cars where id in (#{[1,2,3,4, "5"].join(", ")})"
# => "select * from Cars where id in (1, 2, 3, 4, 5)" 
2.3.1 :004 > db.execute qry
# => [[1, "Audi", 52642], [2, "Mercedes", 57127], [3, "Skoda", 9000], [4, "Volvo", 29000], [5, "Bentley", 350000]]

Upvotes: 1

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