SET @d1 = '1950-01-01';
SET @d2 = '1995-12-31';

-- SELECT  DATE_ADD(@d1,INTERVAL DATEDIFF(@d2,@d1)* RAND() DAY)  ;

INSERT INTO users (user_id,nickname,birthday)
SELECT @ui:=@ui+1,u.*
FROM(SELECT @ui:=0) AS q,(SELECT nickname,(SELECT  DATE_ADD(@d1,INTERVAL DATEDIFF(@d2,@d1)* RAND() DAY)) AS  birthday
  FROM (SELECT CONCAT(t1.s,t2.s,t3.s,t4.s,t5.s) AS nickname
FROM (SELECT 'a' AS s UNION SELECT 'b'  UNION SELECT 'c'  UNION SELECT 'd'  UNION SELECT 'f'  UNION SELECT 'g'  UNION SELECT 'h'  UNION SELECT 'i'  UNION SELECT 'k'  UNION SELECT 'l'  UNION SELECT 'm'  UNION SELECT 'n' UNION SELECT 'o' UNION SELECT 'p' UNION SELECT 'q' UNION SELECT 'r' UNION SELECT 's' UNION SELECT 't' UNION SELECT 'u' UNION SELECT 'v' UNION SELECT 'w' UNION SELECT 'x' UNION SELECT 'y' UNION SELECT 'z' ORDER BY RAND()) AS t1 ,
  (SELECT 'a' AS s UNION SELECT 'b'  UNION SELECT 'c'  UNION SELECT 'd'  UNION SELECT 'f'  UNION SELECT 'g'  UNION SELECT 'h'  UNION SELECT 'i'  UNION SELECT 'k'  UNION SELECT 'l'  UNION SELECT 'm'  UNION SELECT 'n' UNION SELECT 'o' UNION SELECT 'p' UNION SELECT 'q' UNION SELECT 'r' UNION SELECT 's' UNION SELECT 't' UNION SELECT 'u' UNION SELECT 'v' UNION SELECT 'w' UNION SELECT 'x' UNION SELECT 'y' UNION SELECT 'z' ORDER BY RAND()) AS t2,
  (SELECT 'a' AS s  UNION SELECT 'b'  UNION SELECT 'c'  UNION SELECT 'd'  UNION SELECT 'f'  UNION SELECT 'g'  UNION SELECT 'h'  UNION SELECT 'i'  UNION SELECT 'k'  UNION SELECT 'l'  UNION SELECT 'm'  UNION SELECT 'n' UNION SELECT 'o' UNION SELECT 'p' UNION SELECT 'q' UNION SELECT 'r' UNION SELECT 's' UNION SELECT 't' UNION SELECT 'u' UNION SELECT 'v' UNION SELECT 'w' UNION SELECT 'x' UNION SELECT 'y' UNION SELECT 'z' ORDER BY RAND()) AS t3,
  (SELECT 'a' AS s  UNION SELECT 'b'  UNION SELECT 'c'  UNION SELECT 'd'  UNION SELECT 'f'  UNION SELECT 'g'  UNION SELECT 'h'  UNION SELECT 'i'  UNION SELECT 'k'  UNION SELECT 'l'  UNION SELECT 'm'  UNION SELECT 'n' UNION SELECT 'o' UNION SELECT 'p' UNION SELECT 'q' UNION SELECT 'r' UNION SELECT 's' UNION SELECT 't' UNION SELECT 'u' UNION SELECT 'v' UNION SELECT 'w' UNION SELECT 'x' UNION SELECT 'y' UNION SELECT 'z' ORDER BY RAND()) AS t4 ,
 (SELECT 'a' AS s  UNION SELECT 'b'  UNION SELECT 'c'  UNION SELECT 'd'  UNION SELECT 'f'  UNION SELECT 'g'  UNION SELECT 'h'  UNION SELECT 'i'  UNION SELECT 'k'  UNION SELECT 'l'  UNION SELECT 'm'  UNION SELECT 'n' UNION SELECT 'o' UNION SELECT 'p' UNION SELECT 'q' UNION SELECT 'r' UNION SELECT 's' UNION SELECT 't' UNION SELECT 'u' UNION SELECT 'v' UNION SELECT 'w' UNION SELECT 'x' UNION SELECT 'y' UNION SELECT 'z' ORDER BY RAND()) AS t5 
  LIMIT 500000) AS n)u;

SELECT u.nickname,u.birthday,DAY(u.birthday) day_of_birth,MONTH(u.birthday) month_of_birth,
 ABS(YEAR(birthday)-YEAR(CURDATE()))-IF(DAYOFYEAR(u.birthday)<=DAYOFYEAR(CURDATE()),0,1) AS age  
FROM users u 
ORDER BY ABS(DATEDIFF(birthday,'1978-11-02')) 
LIMIT 5;