INSERT INTO `book_members` (`no`,`userid`,`password`,`username`,`email`,`phone`,`photo`) VALUES (NULL, 'info','info','컴퓨터정보','info@ansan.ac.kr','+82314006971',NULL);<br />
<b>Fatal error</b>:  Uncaught mysqli_sql_exception: Duplicate entry 'info' for key 'userid' in /users/2021/i2151008/public_html/2022/WebDB/mysql_test.php:9
Stack trace:
#0 /users/2021/i2151008/public_html/2022/WebDB/mysql_test.php(9): mysqli_query()
#1 {main}
  thrown in <b>/users/2021/i2151008/public_html/2022/WebDB/mysql_test.php</b> on line <b>9</b><br />