


PHP's PDO connection database is very important in data operations. This article will explain its related content in detail.
PHP’s PDO connection database is an object-oriented database data object
The reason why I choose PDO to connect the database is because PDO is suitable for any database
And mysqli, only Suitable for mysql, there is no one that is good or bad, just use whichever one is easy to use.
First of all, of course we have to connect to the database. Then PDO has a specific statement to connect to the database:
$link= new PDO("mysql:host=$servername;dbname=myDB", $username, $password); 通常$servername,myDB,$username,$password都是变量,为了安全,我们可以在conf.php文件下define(定义)他们 define("DB_HOST", "localhost"); define("DB_USER", "root"); define("DB_PWD", "123456"); define("DB_DBNAME", "blog"); define("DB_CHARSET","utf8");
Then use them:
$link = new PDO("mysql:host=".DB_HOST.";dbname=".DB_DBNAME."", DB_USER, DB_PWD);
Usually, we have to connect to the database again when adding, deleting, modifying, and querying, so we usually return $link; to return the result, call connect()
function connect(){ try { $link = new PDO("mysql:host=".DB_HOST.";dbname=".DB_DBNAME."", DB_USER, DB_PWD); //设置PDO错误模式,用于抛出异常 $link->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); } catch (PDOException $e) { echo "数据库连接失败".$e->getMessage(); } return $link; }
every time you use it. In this way, the connect() method is completed.
After that we want to insert data, let’s read on
First think about, what is needed to insert data?
insert into {$table}($key) values {$values};
This is a sql statement, and it is also the sql statement I will use.
I use variables to represent what our sql statement needs, $table, $key, $values
$table seems to be easier for us to find, just get a variable, but What about $key and $values? Can they be obtained at the same time?
At this time we can use $array:
array_key() and array_values() these two functions can obtain $key and $values at the same time
Then this It’s simple, we only need two variables $table and $array
So, we should add two variables to our insert($table,$array) method
Then we have to consider the splicing of data, so I won’t go into details one by one, because you can understand it at a glance
Go directly to the code:
function insert($table,$array){ try { $conn = connect(); $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); $key = join(",", array_keys($array)); $values = "'".join("','", array_values($array))."'"; $sql = "insert into {$table}($key) values {$values}"; $result = $conn->exec($sql); return $conn->lastInsertId(); } catch (PDOException $e) { echo "插入失败".$e->getMessage(); } }
Okay, there are a lot of code words Feeling, so I will do this today, and then there will be update(), delete() and other methods to share with you
Although these are old things, I think I should write them down in a solid way. Come out
This article explains the relevant content of php's PDO connection to the database. For more related content, please pay attention to the php Chinese website.
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The above is the detailed content of Interpret the relevant content of php's PDO connection to the database. For more information, please follow other related articles on the PHP Chinese website!

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。

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。

php判断有没有小数点的方法:1、使用“strpos(数字字符串,'.')”语法,如果返回小数点在字符串中第一次出现的位置,则有小数点;2、使用“strrpos(数字字符串,'.')”语句,如果返回小数点在字符串中最后一次出现的位置,则有。

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。

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。

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。


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