mysql - perl fetchrow_array 只返回最后一列而不是所有列-6ren

mysql - perl fetchrow_array 只返回最后一列而不是所有列

转载作者：行者123 更新时间：2023-11-28 23:25:35

我正在编写一个名为“hlstats.pl”的脚本，它是来自 http://www.hlstats-community.org/ 的半条命游戏的统计服务器

我正在尝试使用 MySQL 在 Windows 上的 Strawberry perl 上运行它。

我已将问题隔离到 fetchrow_array，只返回查询中的最后一列。
这是我从 hlstats.pl 修改后的代码片段

# load the options from DB
my $result = &doQuery("SELECT keyname, value FROM `${db_prefix}_Options`");
my @row;
while (@row = $result->fetchrow_array()) {
  foreach $field (@row) {
    if (defined($field)) {
      print "$field\n";
    } else {    
      print "<NULL>\n";
    }
  }
} 
##my ($keyname, $value, %oHash);
##while( ($keyname, $value) = $result->fetchrow_array ) {
##  # $oHash{$keyname} = $value;
##  print $keyname;
##  print "\n";
##}
$result->finish();

如果它是最后一个，它会打印出“值”列中的所有值，我可以反转它，它会打印所有“键名”列中的值，如果我在查询中移动这些值。我不清楚为什么我们没有收到所有的专栏。

这是为 MSWin32-x86-多线程构建的 perl，v5.10.0

MySQL 版本 5.7.10

“perldoc perllocal”输出

  Thu Jan 29 21:17:27 2009: "Module" ExtUtils::MakeMaker
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 6.48"

    *   "EXE_FILES: bin/instmodsh"

  Thu Jan 29 21:17:32 2009: "Module" File::Path
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.07"

    *   "EXE_FILES: "

  Thu Jan 29 21:17:38 2009: "Module" ExtUtils::Command
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.16"

    *   "EXE_FILES: "

  Thu Jan 29 21:17:47 2009: "Module" Win32API::File
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.1101"

    *   "EXE_FILES: "

  Thu Jan 29 21:18:05 2009: "Module" ExtUtils::Install
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.52"

    *   "EXE_FILES: "

  Thu Jan 29 21:18:10 2009: "Module" ExtUtils::Manifest
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.56"

    *   "EXE_FILES: "

  Thu Jan 29 21:18:34 2009: "Module" Test::Harness
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 3.14"

    *   "EXE_FILES: bin/prove"

  Thu Jan 29 21:18:43 2009: "Module" Test::Simple
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.86"

    *   "EXE_FILES: "

  Thu Jan 29 21:18:48 2009: "Module" ExtUtils::CBuilder
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.24"

    *   "EXE_FILES: "

  Thu Jan 29 21:18:54 2009: "Module" ExtUtils::ParseXS
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.19"

    *   "EXE_FILES: "

  Thu Jan 29 21:19:05 2009: "Module" version
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.76"

    *   "EXE_FILES: "

  Thu Jan 29 21:19:11 2009: "Module" IO::Compress::Base
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.015"

    *   "EXE_FILES: "

  Thu Jan 29 21:19:23 2009: "Module" Compress::Raw::Zlib
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.015"

    *   "EXE_FILES: "

  Thu Jan 29 21:19:33 2009: "Module" Compress::Raw::Bzip2
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.015"

    *   "EXE_FILES: "

  Thu Jan 29 21:20:34 2009: "Module" IO::Compress::Zlib
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.015"

    *   "EXE_FILES: "

  Thu Jan 29 21:20:47 2009: "Module" IO::Compress::Bzip2
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.015"

    *   "EXE_FILES: "

  Thu Jan 29 21:20:55 2009: "Module" Compress::Zlib
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.015"

    *   "EXE_FILES: "

  Thu Jan 29 21:21:18 2009: "Module" Compress::Bzip2
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.09"

    *   "EXE_FILES: "

  Thu Jan 29 21:21:24 2009: "Module" IO::Zlib
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.09"

    *   "EXE_FILES: "

  Thu Jan 29 21:21:31 2009: "Module" Cwd
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 3.29"

    *   "EXE_FILES: "

  Thu Jan 29 21:21:53 2009: "Module" File::Temp
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.21"

    *   "EXE_FILES: "

  Thu Jan 29 21:22:03 2009: "Module" Win32::WinError
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.03"

    *   "EXE_FILES: "

  Thu Jan 29 21:22:14 2009: "Module" Win32API::Registry
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.30"

    *   "EXE_FILES: "

  Thu Jan 29 21:22:19 2009: "Module" Win32::TieRegistry
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.25"

    *   "EXE_FILES: "

  Thu Jan 29 21:22:24 2009: "Module" File::HomeDir
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.82"

    *   "EXE_FILES: "

  Thu Jan 29 21:22:29 2009: "Module" File::Which
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.05"

    *   "EXE_FILES: bin/pwhich"

  Thu Jan 29 21:22:42 2009: "Module" Archive::Zip
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.26"

    *   "EXE_FILES: bin/crc32"

  Thu Jan 29 21:22:46 2009: "Module" Package::Constants
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.02"

    *   "EXE_FILES: "

  Thu Jan 29 21:22:51 2009: "Module" IO::String
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.08"

    *   "EXE_FILES: "

  Thu Jan 29 21:22:59 2009: "Module" Archive::Tar
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.44"

    *   "EXE_FILES: bin/ptar bin/ptardiff"

  Thu Jan 29 21:23:04 2009: "Module" Parse::CPAN::Meta
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.04"

    *   "EXE_FILES: "

  Thu Jan 29 21:23:16 2009: "Module" YAML
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.68"

    *   "EXE_FILES: "

  Thu Jan 29 21:23:23 2009: "Module" Digest::MD5
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.38"

    *   "EXE_FILES: "

  Thu Jan 29 21:23:29 2009: "Module" Digest::SHA1
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.11"

    *   "EXE_FILES: "

  Thu Jan 29 21:23:38 2009: "Module" Digest::SHA
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 5.47"

    *   "EXE_FILES: shasum"

  Thu Jan 29 21:25:58 2009: "Module" CPAN
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.9301"

    *   "EXE_FILES: scripts/cpan"

  Thu Jan 29 21:26:05 2009: "Module" Term::ReadKey
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.30"

    *   "EXE_FILES: "

  Thu Jan 29 21:26:09 2009: "Module" Term::ReadLine
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.0302"

    *   "EXE_FILES: "

  Thu Jan 29 21:26:13 2009: "Module" Text::Glob
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.08"

    *   "EXE_FILES: "

  Thu Jan 29 21:26:24 2009: "Module" URI
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.37"

    *   "EXE_FILES: "

  Thu Jan 29 21:26:28 2009: "Module" HTML::Tagset
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 3.20"

    *   "EXE_FILES: "

  Thu Jan 29 21:26:41 2009: "Module" HTML::Parser
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 3.59"

    *   "EXE_FILES: "

  Thu Jan 29 21:27:18 2009: "Module" LWP
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 5.823"

    *   "EXE_FILES: bin/lwp-request bin/lwp-mirror bin/lwp-rget
        bin/lwp-download"

  Thu Jan 29 21:27:31 2009: "Module" LWP::Online
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.07"

    *   "EXE_FILES: "

  Thu Jan 29 21:27:56 2009: "Module" Win32::File
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.06"

    *   "EXE_FILES: "

  Thu Jan 29 21:28:17 2009: "Module" File::Remove
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.42"

    *   "EXE_FILES: "

  Thu Jan 29 21:28:21 2009: "Module" Win32::File::Object
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.01"

    *   "EXE_FILES: "

  Thu Jan 29 21:28:45 2009: "Module" Win32::API
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.58"

    *   "EXE_FILES: "

  Thu Jan 29 21:29:05 2009: "Module" Params::Util
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.35"

    *   "EXE_FILES: "

  Thu Jan 29 21:29:14 2009: "Module" IPC::Run3
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.042"

    *   "EXE_FILES: "

  Thu Jan 29 21:29:19 2009: "Module" Test::Script
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.03"

    *   "EXE_FILES: "

  Thu Jan 29 21:29:24 2009: "Module" Win32::Env::Path
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.01"

    *   "EXE_FILES: script/win32envpath"

  Thu Jan 29 21:29:46 2009: "Module" Parse::Binary
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.11"

    *   "EXE_FILES: "

  Thu Jan 29 21:29:51 2009: "Module" Win32::Exe
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.11"

    *   "EXE_FILES: script/exe_update.pl"

  Thu Jan 29 21:30:32 2009: "Module" Math::BigInt
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.89"

    *   "EXE_FILES: "

  Thu Jan 29 21:30:52 2009: "Module" Math::BigInt::FastCalc
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.19"

    *   "EXE_FILES: "

  Thu Jan 29 21:31:14 2009: "Module" Math::BigRat
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.22"

    *   "EXE_FILES: "

  Thu Jan 29 21:31:37 2009: "Module" Math::BigInt::GMP
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.24"

    *   "EXE_FILES: "

  Thu Jan 29 21:31:49 2009: "Module" XML::Parser
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.36"

    *   "EXE_FILES: "

  Thu Jan 29 21:32:18 2009: "Module" XML::NamespaceSupport
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.09"

    *   "EXE_FILES: "

  Thu Jan 29 21:32:28 2009: "Module" XML::SAX
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.96"

    *   "EXE_FILES: "

  Thu Jan 29 21:32:41 2009: "Module" XML::LibXML::Common
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.13"

    *   "EXE_FILES: "

  Thu Jan 29 21:33:01 2009: "Module" XML::LibXML
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.69"

    *   "EXE_FILES: "

  Thu Jan 29 21:33:30 2009: "Module" PAR::Dist
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.43"

    *   "EXE_FILES: "

  Thu Jan 29 21:33:37 2009: "Module" PAR::Dist::FromPPD
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.03"

    *   "EXE_FILES: bin/ppd2par"

  Thu Jan 29 21:33:42 2009: "Module" PAR::Dist::InstallPPD
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.02"

    *   "EXE_FILES: bin/parinstallppd"

  Thu Jan 29 21:34:18 2009: "Module" IO::Stringy
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.110"

    *   "EXE_FILES: "

  Thu Jan 29 21:34:41 2009: "Module" Tree::DAG_Node
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.06"

    *   "EXE_FILES: "

  Thu Jan 29 21:35:03 2009: "Module" Test::Warn
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.11"

    *   "EXE_FILES: "

  Thu Jan 29 21:35:21 2009: "Module" Test::Tester
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.107"

    *   "EXE_FILES: "

  Thu Jan 29 21:35:27 2009: "Module" Test::NoWarnings
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.084"

    *   "EXE_FILES: "

  Thu Jan 29 21:35:34 2009: "Module" Test::Deep
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.103"

    *   "EXE_FILES: "

  Thu Jan 29 21:35:39 2009: "Module" DBM::Deep
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.0013"

    *   "EXE_FILES: "

  Thu Jan 29 21:35:59 2009: "Module" YAML::Tiny
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.36"

    *   "EXE_FILES: "

  Thu Jan 29 21:36:23 2009: "Module" AutoLoader
*       "installed into: C:\strawberry\perl\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 5.68"

    *   "EXE_FILES: "

  Thu Jan 29 21:36:29 2009: "Module" PAR
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.984"

    *   "EXE_FILES: "

  Thu Jan 29 21:36:34 2009: "Module" PAR::Repository::Query
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.12"

    *   "EXE_FILES: "

  Thu Jan 29 21:36:39 2009: "Module" PAR::Repository::Client
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.21"

    *   "EXE_FILES: "

  Thu Jan 29 21:36:49 2009: "Module" PPM
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.01_01"

    *   "EXE_FILES: bin/ppm.pl"

  Thu Jan 29 21:37:09 2009: "Module" Number::Compare
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.01"

    *   "EXE_FILES: "

  Thu Jan 29 21:37:19 2009: "Module" pler
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.34"

    *   "EXE_FILES: script/pler"

  Thu Jan 29 21:37:44 2009: "Module" Data::Compare
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.21"

    *   "EXE_FILES: "

  Thu Jan 29 21:37:50 2009: "Module" CPAN::Checksums
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 2.02"

    *   "EXE_FILES: "

  Thu Jan 29 21:37:56 2009: "Module" File::chmod
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.32"

    *   "EXE_FILES: "

  Thu Jan 29 21:38:01 2009: "Module" CPAN::Inject
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.11"

    *   "EXE_FILES: script/cpaninject"

  Thu Jan 29 21:38:15 2009: "Module" pip
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.13"

    *   "EXE_FILES: script/pip"

  Thu Jan 29 21:39:33 2009: "Module" DBI
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.607"

    *   "EXE_FILES: dbiproxy dbiprof dbilogstrip"

  Thu Jan 29 21:40:00 2009: "Module" DBD::SQLite
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 1.14"

    *   "EXE_FILES: "

  Thu Jan 29 21:40:20 2009: "Module" CPAN::DistnameInfo
*       "installed into: C:\strawberry\perl\site\lib"

    *   "LINKTYPE: dynamic"

    *   "VERSION: 0.07"

    *   "EXE_FILES: "

use strict;
use warnings;

use DBI;

print map "$_\n",
      DBI->available_drivers;

输出是:

数据库管理
例子P
文件
打野
多路复用
代理
SQLite
海绵
数据库

最佳答案

很有可能你的真实代码有这个

while ( $row = $result->fetchrow_array() ) {

    foreach $field ( $row ) {

        if ( defined($field) ) {
            print "$field\n";
        }
        else {    
            print "<NULL>\n";
        }
    }
}

documentation for fetchrow_array说这个

If called in a scalar context for a statement handle that has more than one column, it is undefined whether the driver will return the value of the first column or the last. So don't do that.

我会写这个

while ( my @row = $result->fetchrow_array ) {
    print "$_\n" for map { $_ // '<NULL>' } @row;
}

或者你可以像这样使用fetchrow_arrayref

while ( my $row = $result->fetchrow_arrayref ) {
    print "$_\n" for map { $_ // '<NULL>' } @$row;
}

当我们看不到您所看到的内容时，可能很难发现错误。请小心显示真正的源代码，或者您已经测试并产生相同症状的东西。

关于mysql - perl fetchrow_array 只返回最后一列而不是所有列，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39536826/

文章推荐： MySQL order by before group by DAY(timestamp)

文章推荐： mysql - 获取文件名记录

文章推荐： mysql - 存在公式减慢查询。需要优化

php - 返回 1 返回 0 VS 返回 true 返回 false
按照目前的情况，这个问题不适合我们的问答形式。我们希望答案得到事实、引用或专业知识的支持，但这个问题可能会引发辩论、争论、投票或扩展讨论。如果您觉得这个问题可以改进并可能重新打开，visit the
php - 什么更快？如果()返回；否则返回；或者如果()返回；返回;
在编码时，我问了自己这个问题: 这样更快吗: if(false) return true; else return false; 比这个？ if(false) return true; return
javascript - 以逻辑运算符返回(&& 返回、|| 返回)
如何在逻辑条件下进行“返回”？在这样的情况下这会很有用 checkConfig() || return false; var iNeedThis=doSomething() || return fa
正则表达式 - 如果第一个数字是 1 返回 1 但如果它是 145 返回 145 但如果它的 133 返回 133
这是我的正则表达式 demo 如问题所述: 如果第一个数字是 1 则返回 1 但如果是 145 则返回 145 但如果是 133 则返回 133 样本数据a: K'8134567 K'81345678
c - 返回-返回!在 C
在代码高尔夫问答部分查看谜题和答案时，我遇到了 this solution返回 1 的最长和最晦涩的方法引用答案， int foo(void) { return! 0; } int bar(
java - springboot 返回 responseentity 返回 JSON
我想在下面返回 JSON。 { "name": "jackie" } postman 给我错误。说明 Unexpected 'n' 这里是 Spring Boot 的新手。 1日龄。有没有正确的方法来
python "is"返回 True 但 "=="返回 False
只要“is”返回 True，“==”不应该返回 True 吗？ In [101]: np.NAN is np.nan is np.NaN Out[101]: True In [102]: np.NAN
Mysql 返回 1 如果找到或根本不存在值，如果存在其他值，返回 0
我需要获取所有在 6 号或 7 号房间或根本不在任何房间的学生的详细信息。如果他们在其他房间，简单地说，我不希望有那个记录。我的架构是: students(roll_no, name,class,.
javascript - ajax 返回 true，但 == 返回 false
我有一个表单，我将它发送到 php 以通过 ajax 插入到 mysql 数据库中。一切顺利，php 返回 "true" 值，但在 ajax 中它显示 false 消息。在这里你可以查看php代码:
android - Kotlin 中的奇怪值比较问题， "==="返回 true 但 "=="返回 false
我在 Kotlin 中遇到了一个非常奇怪的无法解释的值比较问题，以下代码打印假 data class Foo ( val a: Byte ) fun main() { val NUM
angular - testability.whenStable() 返回， testability.isStable() 返回 false
请注意，这并非特定于 Protractor。问题在于 Angular 2 的内置 Testability service Protractor 碰巧使用。 Protractor 调用 Testabil
vba - CountA 返回 0，WorksheetFunction.CountA 返回 1
在调试窗口中，以下表达式均返回 1。 Application.WorksheetFunction.CountA(Cells(4 + (i - 1) * rows_per_record, 28) & "
json - OPTIONS 返回 204，POST 返回 200 但数据库中没有输入数据
我在本地使用 jsonplaceholder ( http://jsonplaceholder.typicode.com/)。我正在通过 extjs rest 代理测试我的 GET 和 POST 调用
c# - Restsharp 返回 403 而 Postman 返回 200
这是 Postman 为成功调用我的页面而提供的(修改后的)代码段。 var client = new RestClient("http://sub.example.com/wp-json/wp/v2
php - Mysqli_query 返回 false 而 Mysqli_error 返回 NULL？
这个问题在这里已经有了答案: What to do with mysqli problems? Errors like mysqli_fetch_array(): Argument #1 must
c - Argc 返回 1，argv 返回 NULL，尽管输入了命令行参数
我想我对 C 命令行参数有点生疏。我查看了我的一些旧代码，但无论这个版本是什么，都会出现段错误。运行方式是 ./foo -n num(其中 num 是用户在命令行中输入的数字) 但不知何故它不起作用
c++ - 命名管道 CreateFile() 返回 INVALID_HANDLE_VALUE，GetLastError() 返回 ERROR_PIPE_BUSY
我已经编写了一个类来处理命名管道连接，如果我创建了一个实例，关闭它，然后尝试创建另一个实例，调用 CreateFile() 返回 INVALID_HANDLE_VALUE，并且 GetLastErro
PHP is_writable() 返回 true 但 file_put_contents() 返回 false
即使 is_writable() 返回 true，我也无法写入文件。当然，该文件存在并且显然是可读的。这是代码: $file = "data"; echo file_get_contents($fil
php - SoapClient 返回 "NULL"，但 __getLastResponse() 返回 XML
下面代码中的变量 $response 为 NULL，尽管它应该是 SOAP 请求的值。 (潮汐列表)。当我调用 $client->__getLastResponse() 时，我从 SOAP 服务获得了
c - LoadImage() 返回 NULL 和 GetLastError() 返回 0
我一直在网上的不同论坛上搜索答案，但似乎没有与我的情况相符的... 我正在使用 Windows 7，VS2010。我有一个使用定时器来调用任务栏刷新功能的应用程序。在该任务栏函数中包含对 LoadI

行者123

个人简介

我是一名优秀的程序员,十分优秀！

作者热门文章

滴滴打车优惠券免费领取

全站热门文章

首页

博学

6Ren·AI

商城

mysql - perl fetchrow_array 只返回最后一列而不是所有列