Warning: mysqli_connect(): (HY000/2002): 由于目标计算机积极拒绝,无法连接。 in C:\web\Apache\httpd-2.4.41-win64-VS16\Apache24\htdocs\PHP\php_mysql_student\conn.php on line 3

Warning: mysqli_set_charset() expects parameter 1 to be mysqli, boolean given in C:\web\Apache\httpd-2.4.41-win64-VS16\Apache24\htdocs\PHP\php_mysql_student\conn.php on line 4

Warning: mysqli_query() expects parameter 1 to be mysqli, boolean given in C:\web\Apache\httpd-2.4.41-win64-VS16\Apache24\htdocs\PHP\php_mysql_student\index.php on line 8

Warning: mysqli_error() expects parameter 1 to be mysqli, boolean given in C:\web\Apache\httpd-2.4.41-win64-VS16\Apache24\htdocs\PHP\php_mysql_student\index.php on line 10
查询sql语句执行失败。错误信息: