Question

I have 2 tables: ‘listings’ and ‘multipleDupeCopies’

All the entries in ‘multipleDupeCopies’ also exist in ‘listings’ and need to be deleted from it.

So I wrote a simple SQLite3 query wrapped in a Ruby script to carry out this task.

Its so simple that I don’t understand why it wouldn’t work. I’ve spent several hours trying to understand it but nothing has changed, tried different ways to write the query still the same result: The entries from listings are not deleted! I can see the output to the text file that’s generated after running the script but the table still has all the entries intact. Nothing deleted!!

Here is the script:

require 'sqlite3'  
db = SQLite3::Database.new('development.sqlite3')  
db.results_as_hash = true;  
rows= db.execute("SELECT * FROM multipleDupeCopies ")  
rows.each do |row|  
puts 'Deleting...'  
rowid = row['id']  
puts rowid  
db.execute("DELETE FROM listings WHERE listings.id = 'rowid' ")  

end

Any suggestions please?

---

EDIT:
Schema for listings

CREATE TABLE "listings" 
(
  "id"            INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
  "name"          VARCHAR(255),
  "telephone"     VARCHAR(255),
  "fax"           VARCHAR(255),
  "suite"         VARCHAR(255),
  "address"       VARCHAR(255),
  "city"          VARCHAR(255),
  "province"      VARCHAR(255),
  "postal_code"   VARCHAR(255),
  "latitude"      VARCHAR(255),
  "longitude"     VARCHAR(255),
  ...............  many more columns NOT relevant
  "created_at"    datetime NOT NULL,
  "updated_at"    datetime NOT NULL
)

Schema for multipleDupeCopies

CREATE TABLE "multipleDupeCopies" 
(
  "id"            INTEGER PRIMARY KEY NOT NULL,
  "name"          VARCHAR(255),
  "telephone"     VARCHAR(255),
  "fax"           VARCHAR(255),
  "suite"         VARCHAR(255),
  "address"       VARCHAR(255),
  "city"          VARCHAR(255),
  "province"      VARCHAR(255),
  "postal_code"   VARCHAR(255),
  "latitude"      VARCHAR(255),
  "longitude"     VARCHAR(255),
  "url"           VARCHAR(255)
)

Answer 1

This query worked for me: Thanks to @a_horse_with_no_name ‘s comment

db.execute("DELETE FROM listings WHERE id IN (SELECT id FROM multipleDupeCopies)")