mysql_fetch_array()的那些事
调试程序时出现这个问题:mysql_fetch_array() expects parameter 1 to be resource, boolean given in
请问是什么问题?
程序如下:
$result2=mysql_query("select sum(score) as sum from ask_score where qid=".$qid."and answerid=".$authid);
$author3 = mysql_fetch_array ( $result2, MYSQL_ASSOC );
$scoresum=$author3["sum"];
$result3=mysql_query("select count(*) as count from ask_score where qid=".$qid);
$author4 = mysql_fetch_array ( $result3, MYSQL_ASSOC );
$scorenum=$author4["count"];
ask_score表:
CREATE TABLE ask_socre(
qid int(10) unsigned NOT NULL default '0',
authorid mediumint(8) unsigned NOT NULL default '0',
answerid mediumint(8) unsigned NOT NULL default '0',
vote_id mediumint(8) unsigned NOT NULL default '0',
score int(2) unsigned NOT NULL default '0',
PRIMARY KEY (qid,authorid)
);
------解决方案--------------------
你的mysql_query返回了一个false,sql语句错误
改成mysql_query(...) or die(mysql_error()); 看sql语句有什么错误
------解决方案--------------------
1.表名
2.加点空格,最好加上单引号
where qid=".$qid."and answerid=".$
where qid=".$qid." and answerid=".$
- PHP code
<?php $qid = '1'; $authid = '1'; $link = mysql_connect('127.0.0.1', 'root', ''); mysql_select_db("test"); $sql2= " select sum(score) as sum from ask_socre where qid='".$qid."' and answerid='".$authid."' "; $result2=mysql_query($sql2); echo $sql2; if($author3 = mysql_fetch_array ( $result2, MYSQL_ASSOC )){ var_dump($author3); $scoresum=$author3["sum"]; } $sql3 = "select count(*) as count from ask_socre where qid='".$qid."' "; $result3=mysql_query($sql3); echo $sql3; if($author4 = mysql_fetch_array ( $result3, MYSQL_ASSOC )){ var_dump($author4); $scorenum=$author4["count"]; } <div class="clear">

APHPDependencyInjectionContainerisatoolthatmanagesclassdependencies,enhancingcodemodularity,testability,andmaintainability.Itactsasacentralhubforcreatingandinjectingdependencies,thusreducingtightcouplingandeasingunittesting.

Select DependencyInjection (DI) for large applications, ServiceLocator is suitable for small projects or prototypes. 1) DI improves the testability and modularity of the code through constructor injection. 2) ServiceLocator obtains services through center registration, which is convenient but may lead to an increase in code coupling.

PHPapplicationscanbeoptimizedforspeedandefficiencyby:1)enablingopcacheinphp.ini,2)usingpreparedstatementswithPDOfordatabasequeries,3)replacingloopswitharray_filterandarray_mapfordataprocessing,4)configuringNginxasareverseproxy,5)implementingcachingwi

PHPemailvalidationinvolvesthreesteps:1)Formatvalidationusingregularexpressionstochecktheemailformat;2)DNSvalidationtoensurethedomainhasavalidMXrecord;3)SMTPvalidation,themostthoroughmethod,whichchecksifthemailboxexistsbyconnectingtotheSMTPserver.Impl

TomakePHPapplicationsfaster,followthesesteps:1)UseOpcodeCachinglikeOPcachetostoreprecompiledscriptbytecode.2)MinimizeDatabaseQueriesbyusingquerycachingandefficientindexing.3)LeveragePHP7 Featuresforbettercodeefficiency.4)ImplementCachingStrategiessuc

ToimprovePHPapplicationspeed,followthesesteps:1)EnableopcodecachingwithAPCutoreducescriptexecutiontime.2)ImplementdatabasequerycachingusingPDOtominimizedatabasehits.3)UseHTTP/2tomultiplexrequestsandreduceconnectionoverhead.4)Limitsessionusagebyclosin

Dependency injection (DI) significantly improves the testability of PHP code by explicitly transitive dependencies. 1) DI decoupling classes and specific implementations make testing and maintenance more flexible. 2) Among the three types, the constructor injects explicit expression dependencies to keep the state consistent. 3) Use DI containers to manage complex dependencies to improve code quality and development efficiency.

DatabasequeryoptimizationinPHPinvolvesseveralstrategiestoenhanceperformance.1)Selectonlynecessarycolumnstoreducedatatransfer.2)Useindexingtospeedupdataretrieval.3)Implementquerycachingtostoreresultsoffrequentqueries.4)Utilizepreparedstatementsforeffi


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

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

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Dreamweaver CS6
Visual web development tools

WebStorm Mac version
Useful JavaScript development tools

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
