my $file = '/var/tmp/temp_data.txt'; ##################### File for reading
open(FILE, '<:encoding(UTF-8)', $file) || die("Unable to open file");
my @fieldss = <FILE>;
close(FILE);
chomp @fieldss;
my @fields = split(':', @fieldss);####################### Splitting the lines in file ##############
####################################### Dereference ############################
my $names = $fields[0];
my $rate = $fields[1];
my $no_of_days = $fields[2];
my $total_salary = $fields[3];
my $total = $fields[4];
my $basic = $fields[5];
my $da = $fields[6];
my $hra = $fields[7];
my $ot_hallowance = $fields[8];
my $gross = $fields[9];
my $epf = $fields[10];
my $nett = $fields[11];
print "$names\n $rate\n";
foreach $names (@fields) {
my $dbh = "DBI:$platform:$database:$host:$port";
my $connect = DBI->connect($dbh, $user, $pw) || die $DBI::errstr;
$query = "SELECT * FROM salary WHERE name IN('sssss', 'ffffff', 'dddddd', 'ddededed', 'garaead', 'adgfdfg', 'gadfredg')";
my $sth = $connect->prepare($query);
$sth->execute() || die $DBI::errstr;
my @data2;
while (@data2 = $sth->fetchrow_array()) {
my $name = $data2[0];
my $email = $data2[1];
if ($names eq $name) { ######################### Comparing names in file and database ########################
上面的代码是使用split函数读取文本文件和数据。我的问题是我在阅读和分割文件时犯了错误。我在运行代码时遇到504错误，我认为这是因为为文本文件中的每一行调用数据库。谢谢你的帮助。
答案 0 :(得分：2)
查看输入文件中的数据是什么样子会很有帮助。但是你的代码肯定会发生一些奇怪的事情。主要问题似乎是这一行：
my @fields = split(':', @fieldss);
split()有两个标量参数 - 要拆分的正则表达式和要拆分的字符串。因此，它在标量上下文中评估@fieldss并获取数组中的元素数。当然，这将是一个整数，不包含冒号。这会导致@fields包含单个元素，即@fieldss中元素的数量。这个例子说明了：
use Data::Dumper;
my @arr = qw[1:foo 2:bar 3:baz];
my @arr2 = split /:/, @arr;
say Dumper @arr2;
我得到的输出是：
$VAR1 = '3';
您设置@fields的代码应该更像这样：
my $file = '/var/tmp/temp_data.txt';
open(my $fh, '<:encoding(UTF-8)', $file)
# Note: Added filename and error code to output.
|| die("Unable to open $file: $!");
my @fields;
while (<$fh>) {
chomp;
push @fields, split /:/;
}
close $fh;
我没有详细查看其余代码，但肯定会提出一些问题。将数组复制到单个变量可能毫无意义，但可以在一个语句中实现：
my ($names, $rate, $no_of_days, $total_salary, $total,
$basic, $da, $hra, $ot_hallowance, $gross, $epf,
$nett) = @fields;
然后你迭代@fields，似乎假设每个元素都是一个名字。也许你需要更详细地解释你正在做的事情。
然而，这些都没有解释您获得的504状态代码。您提到您正在为文本文件中的每一行运行数据库查询。你在循环的每次迭代中都是完全相同的查询，这当然是真的 - 这似乎是非常浪费的（只运行一次并将结果存储在一个变量中），但是，我们已经确定{{1}只能包含一个元素，你的循环只运行一次而你只查询一次数据库。
严格地说，这可能不是你问题的答案。但是你的问题让很多事情无法解释，以至于无法回答。希望这能让您深入了解如何改善您的计划，以便我们能够开始解决当前隐藏的实际问题。
更新：我刚刚意识到输入文件的结构是什么。您可能希望使用以下代码将其读入哈希数组：
@fields答案 1 :(得分：0)
我甚至不知道你的档案是什么样的。但是我之前在将蛋白质数据库（PDB）文件读入一个数组时，已经完成了这种类型的事情，然后将它们分隔成我的空白分隔的列。我无法保证我的代码能够正常工作，因为我甚至没有你的文件，但无论如何问题是你如何读取文件然后将其拆分成列是问题，是的...
您的拆分无法正常工作，因为您没有拆分，但是您的列是分开的，可能是逗号或至少一个空格。但我从未见过像你所说的用冒号分隔的文件中的列。此外，是的，您可以将文件读入数组，但是要将所有列作为每行的标量，我认为您需要在循环中继续这样做，否则您对每个列都有一个单独的值，不会延伸到整个所有文件。好的，你真的分裂了一个冒号。我很抱歉这个麻烦。请原谅我。
#!/usr/bin/env perl
# Program Description: _________
use strict;
use warnings;
use feature 'say'; # say is like print, but you don't need to type \n.
my $file = '/var/tmp/temp_data.txt'; ##################### File for reading
my $filehandle; # Just like your bareword filehandle FILE.
my @fields = (); # My use of fields is the same as yours.
open($filehandle, '<', $file) or die "Could not open file $_ because $!";
my @All_Lines = <$filehandle>; # This is just everything in the file ... all lines.
my $line; # Our current line which will be useful for the split.
close $filehandle;
# We will declare all of our variables outside of a loop
# That we split all the columns of the file on on colon.
# ... declaring our variables now so they don't get locked in our loop.
my $names;
my $rate;
my $no_of_days;
my $total_salary;
my $total;
my $basic;
my $da;
my $hra;
my $ot_hallowance;
my $gross;
my $epf;
my $nett;
# Iterating over ever line of the file in a foreach loop.
foreach $line (@All_Lines)
{
@fields = split(':', $line); # splitting on a colon.
$names = $fields[0];
$rate = $fields[1];
$no_of_days = $fields[2];
$total_salary = $fields[3];
$total = $fields[4];
$basic = $fields[5];
$da = $fields[6];
$hra = $fields[7];
$ot_hallowance = $fields[8];
$gross = $fields[9];
$epf = $fields[10];
$nett = $fields[11];
say "$names $rate";
# Then I'm pretty sure that I can dump the rest of your code here
# And you should because @fields is now within this foreach loop. It doesn't exist anywhere else.
# I'm pretty sure I'm justified in removing your foreach loop here
# Because in mine, the column of names will be read and operated on line by line.
# Also, your goal was to iterate over $names with a foreach loop
# which I'm doing right now, but where are you operating on it?
# Perhaps you should declare these variables with "my" before we start looping through all the lines of the file one line at a time.
# But I think you will be okay having them here.
my $dbh = "DBI:$platform:$database:$host:$port";
my $connect = DBI->connect($dbh, $user, $pw) || die $DBI::errstr;
# You didn't declare query with "my $query". I think you should, especially since I classically enabled "use strict".
$query = "SELECT * FROM salary WHERE name IN('sssss', 'ffffff', 'dddddd', 'ddededed', 'garaead', 'adgfdfg', 'gadfredg')";
my $sth = $connect->prepare($query);
$sth->execute() || die $DBI::errstr;
my @data2;
# So @data2 gets formed when you start the while loop, right?
while (@data2 = $sth->fetchrow_array())
{
my $name = $data2[0];
my $email = $data2[1];
if ($names eq $name)
{
######################### Comparing names in file and database ########################
} # This bracket ends your if conditional
} # This bracket ends your while loop.
} # This bracket ends my foreach loop that you want to stay within.
# Note: Commenting where brackets begin and end can be really useful when you are trying to stay within a loop.
注意：我根据文件中的一个或多个空格测试了拆分 这是一个看起来像这个由一个或多个空格分隔的PDB文件，PDB文件的每一行可以逐行隔离，所以我很确定这将对你的文件起作用。
ATOM 38 CB PHE A 7 15.240 41.685 54.772 1.00 10.03 C
ATOM 39 CG PHE A 7 15.740 42.936 54.063 1.00 12.39 C
ATOM 40 CD1 PHE A 7 15.096 44.166 54.328 1.00 11.59 C
ATOM 41 CD2 PHE A 7 16.851 42.864 53.189 1.00 10.59 C
ATOM 42 CE1 PHE A 7 15.540 45.310 53.626 1.00 12.79 C
ATOM 43 CE2 PHE A 7 17.329 44.058 52.581 1.00 13.07 C
ATOM 44 CZ PHE A 7 16.651 45.259 52.776 1.00 12.33 C
ATOM 156 CG GLU A 20 14.635 48.596 50.249 1.00 9.28 C
ATOM 157 CD GLU A 20 15.173 49.229 51.481 1.00 10.96 C
ATOM 158 OE1 GLU A 20 15.790 50.279 51.395 1.00 11.04 O
ATOM 159 OE2 GLU A 20 14.851 48.625 52.550 1.00 13.31 O
现在，我通常会在程序中稍后关闭文件，但是你是对的。您可以将其保存到数组中，即使在关闭文件后也可以逐行操作该数组。