Backend Development
PHP Tutorial
Interpret the relevant content of php's PDO connection to the database
Interpret the relevant content of php's PDO connection to the database
Jun 08, 2018 pm 02:41 PM
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都是變量，為了安全，我們可以在conf.php文件下define（定義）他們
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);
//設(shè)置PDO錯誤模式，用于拋出異常
$link->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
echo "數(shù)據(jù)庫連接失敗".$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 $e) {
echo "插入失敗".$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.
Related recommendations:
How to use code to recursively obtain the value of a specified key in an array through PHP
Through PHP Realize reading a file size of 1G
Explain the PHP class initialization function code
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!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
How do I stay up-to-date with the latest PHP developments and best practices?
Jun 23, 2025 am 12:56 AM
TostaycurrentwithPHPdevelopmentsandbestpractices,followkeynewssourceslikePHP.netandPHPWeekly,engagewithcommunitiesonforumsandconferences,keeptoolingupdatedandgraduallyadoptnewfeatures,andreadorcontributetoopensourceprojects.First,followreliablesource
How to set PHP time zone?
Jun 25, 2025 am 01:00 AM
TosettherighttimezoneinPHP,usedate_default_timezone_set()functionatthestartofyourscriptwithavalididentifiersuchas'America/New_York'.1.Usedate_default_timezone_set()beforeanydate/timefunctions.2.Alternatively,configurethephp.inifilebysettingdate.timez
What are the best practices for writing clean and maintainable PHP code?
Jun 24, 2025 am 12:53 AM
The key to writing clean and easy-to-maintain PHP code lies in clear naming, following standards, reasonable structure, making good use of comments and testability. 1. Use clear variables, functions and class names, such as $userData and calculateTotalPrice(); 2. Follow the PSR-12 standard unified code style; 3. Split the code structure according to responsibilities, and organize it using MVC or Laravel-style catalogs; 4. Avoid noodles-style code and split the logic into small functions with a single responsibility; 5. Add comments at key points and write interface documents to clarify parameters, return values ??and exceptions; 6. Improve testability, adopt dependency injection, reduce global state and static methods. These practices improve code quality, collaboration efficiency and post-maintenance ease.
How do I execute SQL queries using PHP?
Jun 24, 2025 am 12:54 AM
Yes,youcanrunSQLqueriesusingPHP,andtheprocessinvolveschoosingadatabaseextension,connectingtothedatabase,executingqueriessafely,andclosingconnectionswhendone.Todothis,firstchoosebetweenMySQLiorPDO,withPDObeingmoreflexibleduetosupportingmultipledatabas
How do I use page caching in PHP?
Jun 24, 2025 am 12:50 AM
PHP page caching improves website performance by reducing server load and speeding up page loading. 1. Basic file cache avoids repeated generation of dynamic content by generating static HTML files and providing services during the validity period; 2. Enable OPcache to compile PHP scripts into bytecode and store them in memory, improving execution efficiency; 3. For dynamic pages with parameters, they should be cached separately according to URL parameters, and avoid cached user-specific content; 4. Lightweight cache libraries such as PHPFastCache can be used to simplify development and support multiple storage drivers. Combining these methods can effectively optimize the caching strategy of PHP projects.
How to quickly test PHP code snippets?
Jun 25, 2025 am 12:58 AM
ToquicklytestaPHPcodesnippet,useanonlinePHPsandboxlike3v4l.orgorPHPize.onlineforinstantexecutionwithoutsetup;runcodelocallywithPHPCLIbycreatinga.phpfileandexecutingitviatheterminal;optionallyusephp-rforone-liners;setupalocaldevelopmentenvironmentwith
How do I use logical operators in PHP (&&, ||, !, and, or, xor)?
Jun 23, 2025 am 12:56 AM
In PHP, logical operators are used to combine or evaluate conditions, and the main operators include &&, and, ||, or, !, and xor. 1. The difference between && and is in priority. && is higher than the assignment operator, while and is lower than the assignment operator, so the behavior is different when combining assignment; 2.|| and or also have similar priority differences, || takes precedence over assignment, while or is processed after assignment; 3.! operator is used to invert Boolean values, often used to check whether the condition is false, and it is recommended to wrap complex expressions in brackets to ensure correct application; 4.xor returns true only when exactly one of the two values ??is true, suitable for mutex condition judgment
How to upgrade PHP version?
Jun 27, 2025 am 02:14 AM
Upgrading the PHP version is actually not difficult, but the key lies in the operation steps and precautions. The following are the specific methods: 1. Confirm the current PHP version and running environment, use the command line or phpinfo.php file to view; 2. Select the suitable new version and install it. It is recommended to install it with 8.2 or 8.1. Linux users use package manager, and macOS users use Homebrew; 3. Migrate configuration files and extensions, update php.ini and install necessary extensions; 4. Test whether the website is running normally, check the error log to ensure that there is no compatibility problem. Follow these steps and you can successfully complete the upgrade in most situations.
