How to make a case-insensitive unique column in SQLite

Question

I haven\'t been able to find the answer to this. I\'m trying to create a table with a unique email address column. And when I do

CREATE TABLE users (
  email         


        

Answer 1

COLLATE NOCASE is your friend:

CREATE TABLE users (
  email TEXT PRIMARY KEY,
  password TEXT NOT NULL CHECK(password<>''),
  UNIQUE (email COLLATE NOCASE)
)

Answer 2

For speed, make all your input lower case first, and use a normal unique column.

This is great for read-more-frequent-than-write use cases because queries just need to compare strings, rather than converting the field first which it must do lots of times to compare.