Mysql - get how many users have used my app only one

Databases
1

Hi all,
in this table I log the users of an e-commerce


CREATE TABLE IF NOT EXISTS user_access (
    id BIGINT UNSIGNED NOT NULL auto_increment,
    session_id CHAR(64) NOT NULL,
    fb_id BIGINT unsigned DEFAULT NULL,
    browser_id SMALLINT NOT NULL,
    so_id SMALLINT NOT NULL,
    device_id SMALLINT NOT NULL,
    referer_id SMALLINT DEFAULT NULL,
    ip VARCHAR(15) NOT NULL,
    log_fb_datetime DATETIME DEFAULT NULL,
    access_start_datetime DATETIME NOT NULL,
    access_end_datetime DATETIME DEFAULT NULL,
    country_code CHAR(2) DEFAULT NULL,
    country_name VARCHAR(255) DEFAULT NULL,
    region_code TINYINT DEFAULT NULL,
    region_name VARCHAR(255) DEFAULT NULL,
    city VARCHAR(255) DEFAULT NULL,
    lat FLOAT( 10, 6 ) DEFAULT 0 ,
    lng FLOAT( 10, 6 ) DEFAULT 0,
    PRIMARY KEY  (id)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8;

if the fb_id is null the user has never sign up to the app
I want to find how many users have used my app only one
and never logged in.
My best :frowning: but it doesn’t work


SELECT COUNT( * ) AS num
FROM sharint_user_access
WHERE fb_id IS NOT NULL
GROUP BY fb_id
HAVING num =1

Can you help me,please ?

2 
SELECT COUNT(*) AS num 
  FROM ( SELECT fb_id
           FROM sharint_user_access 
          WHERE fb_id IS NOT NULL  
         GROUP 
             BY fb_id 
         HAVING COUNT(*) = 1 ) AS these_guys
3

:wink: thanks