


This article summarizes and shares some solutions to some problems that may often be encountered in PHP development when PHP cannot connect to the MySQL database. Friends in need can refer to it.
Question 1
I installed mysql and php on my notebook today, and everything was installed normally (php@IIS7.5-fastCGI). However, when using phpmyadmin to connect and test, an error of "#2002 Unable to connect" appears. The same problem occurs when using other programs.
After checking, the mysql extension of php is installed correctly and the mysql service starts normally--that's strange. I used navicat to connect again and it was connected. . It seems that there is a problem with the communication between php and mysql.
After searching on Baidu, the problem was found:
The mysql_connect() function database server parameter is currently set to localhost, but it can be accessed normally after it is changed to 127.0.0.1.
The system hosts file does not provide resolution from 127.0.0.1 to localhost.
Solution (taking win7 system as an example): Find the C:\Windows\System32\drivers\etc\hosts file. The default is read-only. You need to copy a copy to another path such as the desktop. Open the file (Open with: Notepad) and add:
at the end of the file127.0.0.1 localhost
If it already exists, remove the "#" in front of it.
Question 2
PHP scripts can run normally, such as phpinfo().
As soon as the "mysql_connect" function appears, there will be no response and no error will be reported.
Such as $conn = mysql_connect("127.0.0.1","root","xxxx") or die("MYSQL database connection failed:".mysql_error());
appears in the apache log directory error.log
PHP Warning: PHP Startup: Unable to load dynamic library 'c:\\php\\ext\\php_mysql.dll'
Solution
Copy "libmysql.dll" to the bin directory of apache. Then restart and observe the error.log. If the error disappears, congratulations.
Another: Online information also says to copy ""libmysql.dll"" and "php_mysql.dll" to windows/system32.
Question 3
The code is as follows
|
Copy code
|
||||
//The above code is omitted
$link_id=@mysql_connect( "localhost ", "sampadm ", "secret "); //The following code is omitted ?> The following prompt appears when running: fatal error: call to undefined function mysql_connect() in var/www/html/mytest.php Solution
A) Click the "Start" menu-> "mysql"-> "mysql5 server"-> "MySQL Command Line Client"
B) Enter password |
LoadModule php5_module "D:/ccopen/php5/php5apache2_2.dll"

php把负数转为正整数的方法:1、使用abs()函数将负数转为正数,使用intval()函数对正数取整,转为正整数,语法“intval(abs($number))”;2、利用“~”位运算符将负数取反加一,语法“~$number + 1”。

实现方法:1、使用“sleep(延迟秒数)”语句,可延迟执行函数若干秒;2、使用“time_nanosleep(延迟秒数,延迟纳秒数)”语句,可延迟执行函数若干秒和纳秒;3、使用“time_sleep_until(time()+7)”语句。

php字符串有下标。在PHP中,下标不仅可以应用于数组和对象,还可应用于字符串,利用字符串的下标和中括号“[]”可以访问指定索引位置的字符,并对该字符进行读写,语法“字符串名[下标值]”;字符串的下标值(索引值)只能是整数类型,起始值为0。

php除以100保留两位小数的方法:1、利用“/”运算符进行除法运算,语法“数值 / 100”;2、使用“number_format(除法结果, 2)”或“sprintf("%.2f",除法结果)”语句进行四舍五入的处理值,并保留两位小数。

在php中,可以使用substr()函数来读取字符串后几个字符,只需要将该函数的第二个参数设置为负值,第三个参数省略即可;语法为“substr(字符串,-n)”,表示读取从字符串结尾处向前数第n个字符开始,直到字符串结尾的全部字符。

判断方法:1、使用“strtotime("年-月-日")”语句将给定的年月日转换为时间戳格式;2、用“date("z",时间戳)+1”语句计算指定时间戳是一年的第几天。date()返回的天数是从0开始计算的,因此真实天数需要在此基础上加1。

方法:1、用“str_replace(" ","其他字符",$str)”语句,可将nbsp符替换为其他字符;2、用“preg_replace("/(\s|\ \;||\xc2\xa0)/","其他字符",$str)”语句。

查找方法:1、用strpos(),语法“strpos("字符串值","查找子串")+1”;2、用stripos(),语法“strpos("字符串值","查找子串")+1”。因为字符串是从0开始计数的,因此两个函数获取的位置需要进行加1处理。


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