use*_*982 1 mysql arrays perl loops if-statement
我试图在两个单独的数据库中采用两个单独的表,并将这些字段相互比较.我写了下面的代码来演示我遇到的问题,因为我无法复制我正在使用的代码.在下面的示例中,我使用的是一个数据库.在代码示例下面,我将提供每个表的转储.在任何情况下都有更好的描述.
reference_table保存original_table中列出的记录.我无法控制original_table的内容.获取这些记录后,在original_table中编辑信息的人员可以更新任何字段,或者他们可以彻底删除该条目.
我的目标是,当回到original_table时,将字段状态更新为禁用,其中original_table中的任何字段不再与我在reference_table中的记录匹配.查看转储时,您会注意到一个名为unique_id的字段.这是original_table的id.
我遇到的两个主要问题是使用reference_table的ident来更新reference_table中的状态,并正确地看到表的相似性.
#!/usr/bin/perl
use strict;
use DBI;
use Data::Dumper;
my $dbh = DBI->connect('dbi:mysql:test','user','password',
{
RaiseError => 1,
AutoCommit => 0
}
) || die "Database connection not made: $DBI::errstr";
my $sql = "SELECT * FROM original_table";
my $sth = $dbh->prepare( $sql ) or die $dbh->errstr;
$sth->execute() or die $sth->errstr;
my @original;
while (my $data = $sth->fetchrow_hashref()){
push(@original, $data);
}
my $sql = "SELECT * FROM reference_table";
my $sth = $dbh->prepare( $sql ) or die $dbh->errstr;
$sth->execute() or die $sth->errstr;
my @reference;
while (my $data = $sth->fetchrow_hashref()){
push(@reference, $data);
}
foreach (sort keys @reference){
unless (exists $original[$_]){
my $sql = "UPDATE reference_table SET status = 'd' WHERE ident $reference[ident]";
my $sth = $dbh->prepare( $sql ) or die $dbh->errstr;
$sth->execute() or die $sth->errstr;
print "$_: not found in Remote Group\n";
next;
}
if ($reference[$_] eq $original[$_]){
print "$_: values are equal\n"
}else{
print "$_: values are not equal\n";
}
}
$dbh->disconnect();
该代码产生以下结果:
0: values are not equal
1: values are not equal
10: values are not equal
11: not found in Remote Group
2: values are not equal
3: values are not equal
4: values are not equal
5: values are not equal
6: values are not equal
7: values are not equal
8: values are not equal
9: values are not equal
每个表的转储:
@原版的
$VAR1 = [
{
'timezone' => 'tz_001',
'status' => 'a',
'full_name' => 'name_001',
'ident' => '1'
},
{
'timezone' => 'tz_002',
'status' => 'a',
'full_name' => 'name_002',
'ident' => '2'
},
{
'timezone' => 'tz_003',
'status' => 'a',
'full_name' => 'name_003',
'ident' => '3'
},
{
'timezone' => 'tz_004',
'status' => 'a',
'full_name' => 'name_004',
'ident' => '4'
},
{
'timezone' => 'tz_005',
'status' => 'a',
'full_name' => 'name_005',
'ident' => '5'
},
{
'timezone' => 'tz_006',
'status' => 'a',
'full_name' => 'name_006',
'ident' => '6'
},
{
'timezone' => 'tz_007',
'status' => 'a',
'full_name' => 'name_007',
'ident' => '7'
},
{
'timezone' => 'tz_008',
'status' => 'a',
'full_name' => 'name_008',
'ident' => '8'
},
{
'timezone' => 'tz_009',
'status' => 'a',
'full_name' => 'name_009',
'ident' => '9'
},
{
'timezone' => 'tz_010',
'status' => 'a',
'full_name' => 'name_010',
'ident' => '10'
},
{
'timezone' => 'tz_011',
'status' => 'a',
'full_name' => 'name_011',
'ident' => '11'
}
];
@参考
$VAR1 = [
{
'timezone' => 'tz_001',
'status' => 'a',
'full_name' => 'name_001',
'ident' => '1',
'unique_id' => '1'
},
{
'timezone' => 'tz_002',
'status' => 'a',
'full_name' => 'name_002',
'ident' => '2',
'unique_id' => '2'
},
{
'timezone' => 'tz_003',
'status' => 'a',
'full_name' => 'name_003',
'ident' => '3',
'unique_id' => '3'
},
{
'timezone' => 'tz_004',
'status' => 'a',
'full_name' => 'name_004',
'ident' => '4',
'unique_id' => '4'
},
{
'timezone' => 'tz_005',
'status' => 'a',
'full_name' => 'name_122',
'ident' => '5',
'unique_id' => '5'
},
{
'timezone' => 'tz_006',
'status' => 'a',
'full_name' => 'name_006',
'ident' => '6',
'unique_id' => '6'
},
{
'timezone' => 'tz_007',
'status' => 'a',
'full_name' => 'name_007',
'ident' => '7',
'unique_id' => '7'
},
{
'timezone' => 'tz_008',
'status' => 'a',
'full_name' => 'name_008',
'ident' => '8',
'unique_id' => '8'
},
{
'timezone' => 'tz_009',
'status' => 'a',
'full_name' => 'name_009',
'ident' => '9',
'unique_id' => '9'
},
{
'timezone' => 'tz_010',
'status' => 'a',
'full_name' => 'name_010',
'ident' => '10',
'unique_id' => '10'
},
{
'timezone' => 'tz_011',
'status' => 'a',
'full_name' => 'name_011',
'ident' => '11',
'unique_id' => '11'
},
{
'timezone' => 'tz_012',
'status' => 'a',
'full_name' => 'name_012',
'ident' => '12',
'unique_id' => '12'
}
];
如果您有其他问题,请告诉我.任何帮助是极大的赞赏.
"UPDATE reference_table SET status = 'd' WHERE ident $reference[ident]"
问题是这个$reference[ident].您正在尝试访问由裸字索引的数组元素ident,但这不起作用.
要纠正此问题,请使用适当的索引$_.下一个问题是@referencehashrefs数组.我假设你想ident在hashref中使用该字段.然后:$reference[$_]{ident}.
我还建议您使用占位符来避免转义时可能出现的问题:
my $sql = "UPDATE reference_table SET status = 'd' WHERE ident ?";
my $sth = $dbh->prepare($sql) or die $dbh->errstr;
$sth->execute($reference[$_]{ident}) or die $sth->errstr;
您的代码存在一些剩余的样式问题,但这应该可以帮到您.