从数据库中删除和更新数据 [英] Deleting and updating data from database

问题描述

我创建了一个连接到数据库的代码，并且我想使用同样的更新按钮从数据库中删除数据。但我只能在表中显示数据并且不能删除。

  my $ q = new CGI; 
 print $ q-> header; 
 print $ q-> start_html（
 -title =>，
）; 
 
＃print $ q-> start_form; 
 ## mysql用户数据库名称
 my $ db =people; 
 ## mysql数据库用户名
 my $ user =root; 
 ## mysql数据库密码
 my $ pass =; 
 
 ##用户主机名：这应该是本地主机，但它也可以是不同的
 my $ host =127.0.0.1; 
 
 ## SQL查询
 my $ query =select ID，Name，Surname，Gender from person; 
 $ b $ my $ dbh = DBI-> connect（DBI：mysql：$ db：$ host，$ user，$ pass）; 
 my $ sqlQuery = $ dbh->准备（$查询）
或死无法准备$ sqlQuery：$ dbh-> errstr\\\
; 
 my $ rv = $ sqlQuery->执行
或死亡无法执行查询：$ sqlQuery-> errstr; 
 
 print start_form（-method =>'post'，-action =>modify.pl）; 
 
我的@aRows; 
 
 while（my @data = $ sqlQuery-> fetchrow_array（））{
 my $ cRowId = hidden（'ID'，$ data [0]）; 
 
 my $ bt1 = submit（'action'，'delete'）; 
 my $ bt2 = submit（'action'，'update'）; 
 
 push @aRows，（$ cRowId，$ q-> Tr（$ q-> td（[$ data [1]，$ data [2]，$ data [3]，$ BT1，BT2 $）））; 
} 
 
 print $ q-> table（{ -  border =>'1'，-align =>'center'，-width =>'100％'} （['Name'，'Surname'，'Gender'，'Delete'，'Update'，]）]），
（$ b $ q-> Tr @aRows，
）; 
 
 print $ q-> input（{ -  type =>'button'，-class =>'button'，-onclick =>window.location.href ='insert。 pl';， -  value =>'Shto'}）; 
 
 print $ q-> end_form; 
 print $ q-> end_html; 
  

delete.pl

 使用CGI; 
使用CGI qw（标准）; 
使用DBI; 
使用CGI :: Carp qw（set_die_handler）; 
使用CGI qw /：all /; 
 BEGIN {
 sub handle_errors {
 my $ msg = shift; 
打印content-type：text / html\\\
\\\
; 
 #proceed发送电子邮件给系统管理员，
＃向浏览器和/或日志写入详细消息，
 #etc .... 
} 
 
 set_die_handler（\& handle_errors）; 
} 
 
 my $ q = CGI-> new（）; 
 
 
 
 my $ db =people; 
 my $ user =root; 
 my $ pass =; 
 my $ host =127.0.0.1; 
 my $ dbh = DBI-> connect（DBI：mysql：$ db：$ host，$ user，$ pass）; （'delete'）{
 my $ row_id = $（$ action $）$（$ action $） Q-> PARAM（ 'ID'）; 
 my $ sth = $ dbh-> prepare（DELETE FROM person WHERE ID = $ row_id）or dieCan not prepare $ query：$ dbh-> errstr\\\
; 
 my $ rv = $ sth-> execute（）或者$ DBI :: errstr; 
打印已删除; 
 my $ sth-> finish（）; 
 my $ dbh->提交或者死亡$ DBI :: errstr; 
 
}} 
  

我不知道问题出在哪里 p>

解决方案

绝大多数Perl CGI问题都可以通过以下方法来解决：

• 在您的代码中添加 use strict 和使用警告
  
• 修复现在出现在错误日志中的所有错误

I have created a code that connects to database and i want to delete data from database using a button the same for update. but i just can display data in a table and cant delete.

  my $q= new CGI;
    print $q->header;
    print $q-> start_html(
       -title   => "",
    );

    # print $q->start_form;
    ## mysql user database name
    my $db = "people";
    ## mysql database user name
    my $user = "root"; 
    ## mysql database password
    my $pass = "";

    ## user hostname : This should be "localhost" but it can be diffrent too
    my $host="127.0.0.1";

    ## SQL query
    my $query = "select ID,Name,Surname,Gender from person";

    my $dbh = DBI->connect("DBI:mysql:$db:$host", $user, $pass);
    my $sqlQuery  = $dbh->prepare($query)
    or die "Can't prepare $sqlQuery: $dbh->errstr\n";
    my $rv = $sqlQuery->execute
    or die "can't execute the query: $sqlQuery->errstr";

    print start_form (-method => 'post', -action => "modify.pl" );

    my @aRows;

    while (my @data = $sqlQuery->fetchrow_array()) {      
       my $cRowId = hidden('ID', $data[0]);

       my $bt1 = submit('action','delete');
       my $bt2 = submit('action','update');

       push @aRows, ($cRowId, $q->Tr($q->td([$data[1], $data[2], $data[3],$bt1,$bt2])));
    }

    print $q->table({-border =>'1', -align =>'center',  -width => '100%'},
       $q->Tr([$q->th([ 'Name', 'Surname', 'Gender', 'Delete', 'Update', ])]),
       @aRows,
    );

    print $q->input({-type => 'button', -class => 'button', -onclick => "window.location.href='insert.pl';", -value => 'Shto'});

    print $q->end_form;  
    print $q->end_html;

delete.pl

use CGI;
use CGI qw(standard);
use DBI;
use CGI::Carp qw(set_die_handler);
use CGI qw/:all/;
    BEGIN {
       sub handle_errors {
          my $msg = shift;
          print "content-type: text/html\n\n";
          #proceed to send an email to a system administrator,
          #write a detailed message to the browser and/or a log,
          #etc....
      }

      set_die_handler(\&handle_errors);
}

my $q = CGI->new();



my $db = "people";
my $user = "root"; 
my $pass = "";
my $host="127.0.0.1";
my $dbh = DBI->connect("DBI:mysql:$db:$host", $user, $pass);
my $action = $q->param('action'){
given ($action){
           when('delete'){
               my $row_id = $q->param('ID');
               my $sth = $dbh->prepare("DELETE FROM person WHERE ID = $row_id ") or die "Can't prepare $query: $dbh->errstr\n";
               my $rv = $sth->execute() or die $DBI::errstr;               
               print "deleted";
my $sth->finish();           
my $dbh->commit or die $DBI::errstr;
          }
    } }

I dont know where may be the problem

解决方案

The vast majority of Perl CGI problems can be solved by:

• Adding use strict and use warnings to your code
• Fixing all of the errors that now appear in your error log

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