Table of Contents
回复讨论(解决方案)
Home Backend Development PHP Tutorial 用PDO查询数据库内容是这样查吗?

用PDO查询数据库内容是这样查吗?

Jun 20, 2016 pm 12:41 PM

为什么我显示这个这个错误?
( ! ) Parse error: syntax error, unexpected 'foreach' (T_FOREACH) in D:\wamp\www\cxblog.php on line 4
这个查询出来是个数组吗?我只想把数据库里面的值取出来 不要数组形式的  应该怎么写呢
 $pdo=new PDO("mysql:host=localhost;dbname=t1","root","");
 $sql=$pdo->query('select * from blog')
 foreach($sql as $row){ 
  print_r($row); 
  } 
?>


回复讨论(解决方案)

PDOStatement PDO::query ( string statement )
mixed PDOStatement::fetch ( [int fetch_style [, int cursor_orientation [, int cursor_offset]]] )
array PDOStatement::fetchAll ( [int fetch_style [, int column_index]] )


PDOStatement PDO::query ( string statement )
mixed PDOStatement::fetch ( [int fetch_style [, int cursor_orientation [, int cursor_offset]]] )
array PDOStatement::fetchAll ( [int fetch_style [, int column_index]] )


英文的看不懂

PDOStatement PDO::query ( string statement )
mixed PDOStatement::fetch ( [int fetch_style [, int cursor_orientation [, int cursor_offset]]] )
array PDOStatement::fetchAll ( [int fetch_style [, int column_index]] )


我知道问题了  我前面$sql没有加结束的分号  现在显示出来的是一个数组  但是我只想要数据

改成这样.

<?php $pdo=new PDO("mysql:host=localhost;dbname=t1","root",""); $sth=$pdo->query('select * from blog') $result = $sth->fetchall(PDO::FETCH_ASSOC); foreach($result as $k=>$v){    print_r($v);}?>
Copy after login
Copy after login
Copy after login

改成这样.

<?php $pdo=new PDO("mysql:host=localhost;dbname=t1","root",""); $sth=$pdo->query('select * from blog') $result = $sth->fetchall(PDO::FETCH_ASSOC); foreach($result as $k=>$v){    print_r($v);}?>
Copy after login
Copy after login
Copy after login


试了一下提示这个错误 怎么回事?
( ! ) Parse error: syntax error, unexpected '$result' (T_VARIABLE) in D:\wamp\www\cxblog2.php on line 4

改成这样.

<?php $pdo=new PDO("mysql:host=localhost;dbname=t1","root",""); $sth=$pdo->query('select * from blog') $result = $sth->fetchall(PDO::FETCH_ASSOC); foreach($result as $k=>$v){    print_r($v);}?>
Copy after login
Copy after login
Copy after login


这样得到的还是数组形式的 我只想得到值

当然是数组形式的!
你 select * from blog
这个 * 表示的是表中的所有字段,php 不可能越俎代庖的将他们链接成一个值
即便表中只有一个字段,但 php 也是不会知道的
因为所有的解释权在你,而不是在 php

当然是数组形式的!
你 select * from blog
这个 * 表示的是表中的所有字段,php 不可能越俎代庖的将他们链接成一个值
即便表中只有一个字段,但 php 也是不会知道的
因为所有的解释权在你,而不是在 php


我这个表只有一列就是content列 我改成select content from blog 还是不行啊

我已经说过了,php 对于数据库查询,总是返回数组的

$pdo=new PDO("mysql:host=localhost;dbname=t1","root",""); $sth=$pdo->query('select * from blog') $result = $sth->fetchall(PDO::FETCH_ASSOC); foreach($result as $k=>$v){    echo $v['content']; //这样不就是但值了吗?}
Copy after login
Copy after login

我已经说过了,php 对于数据库查询,总是返回数组的

$pdo=new PDO("mysql:host=localhost;dbname=t1","root",""); $sth=$pdo->query('select * from blog') $result = $sth->fetchall(PDO::FETCH_ASSOC); foreach($result as $k=>$v){    echo $v['content']; //这样不就是但值了吗?}
Copy after login
Copy after login


哦哦可以了 谢谢 我再好好看看
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How does session hijacking work and how can you mitigate it in PHP? How does session hijacking work and how can you mitigate it in PHP? Apr 06, 2025 am 12:02 AM

Session hijacking can be achieved through the following steps: 1. Obtain the session ID, 2. Use the session ID, 3. Keep the session active. The methods to prevent session hijacking in PHP include: 1. Use the session_regenerate_id() function to regenerate the session ID, 2. Store session data through the database, 3. Ensure that all session data is transmitted through HTTPS.

Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Apr 05, 2025 am 12:04 AM

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

Describe the SOLID principles and how they apply to PHP development. Describe the SOLID principles and how they apply to PHP development. Apr 03, 2025 am 12:04 AM

The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.

How to debug CLI mode in PHPStorm? How to debug CLI mode in PHPStorm? Apr 01, 2025 pm 02:57 PM

How to debug CLI mode in PHPStorm? When developing with PHPStorm, sometimes we need to debug PHP in command line interface (CLI) mode...

How to automatically set permissions of unixsocket after system restart? How to automatically set permissions of unixsocket after system restart? Mar 31, 2025 pm 11:54 PM

How to automatically set the permissions of unixsocket after the system restarts. Every time the system restarts, we need to execute the following command to modify the permissions of unixsocket: sudo...

Explain late static binding in PHP (static::). Explain late static binding in PHP (static::). Apr 03, 2025 am 12:04 AM

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

How to send a POST request containing JSON data using PHP's cURL library? How to send a POST request containing JSON data using PHP's cURL library? Apr 01, 2025 pm 03:12 PM

Sending JSON data using PHP's cURL library In PHP development, it is often necessary to interact with external APIs. One of the common ways is to use cURL library to send POST�...

See all articles