SQLite: Why does ON CONFLICT IGNORE return a duplicate error?

Question

SQLite

Guided by the documentation, I created a table with a unique index and fields containing ignoring errors with duplicate records.
Here's the fiddle: sqlfiddle.com/#!7/77dc6/5
Logically, two out of three inserts should create records in the table, ignoring the duplicate error.
However, this does not happen.
The first three pages in Google on this topic (all links are purple :) ) claim that I'm doing everything right. But doesn't work. Why?
[SOLUTION]
The ON CONFLICT IGNORE condition (possible options in the documentation ) can be used in several cases.
1) when one column should be unique;

CREATE TABLE User (
 id integer PRIMARY KEY,
 first_name text NOT NULL UNIQUE ON CONFLICT IGNORE,
 last_name text NOT NULL
);

2) when several columns must be unique, i.e. a composite index

CREATE TABLE User (
 id integer PRIMARY KEY,
 first_name text NOT NULL,
 last_name text NOT NULL,
 UNIQUE(first_name, last_name)
 ON CONFLICT IGNORE
);