判断HASH VALUE的未定义值出错（已解决）

jjqing

#!/usr/bin/perl
use strict;
use warnings;
use diagnostics;
use Smart::Comments '###';

my (%hash,$result);

%hash = (
    cluster_name => undef,
    column_name => 'OBJ#',
    column_position => '1',
    extents => '102',
    index_name => 'I_IDL_UB11',
    index_size => 2097152,
    index_tablespace_name => 'SYSTEM',
    index_type => 'NORMAL',
    iot_type => undef,
    nested => 'NO',
    owner => 'SYS',
    table_name => 'IDL_UB1$',
    table_size => 260046848,
    tablespace_name => 'SYSTEM',
    temporary => 'N'
);
### %hash
push ( @$result, { %hash } );
### $result

foreach my $a ( @{ $result } ) {
    my $hash;
    ### $a
    if ( defined $a->{cluster_name} ) { #此处为何老是报"Use of uninitialized value"
        $hash->{table_type} = 'CLUSTER';
    }
    elsif ( defined $a->{iot_type} ) {
        $hash->{table_type} = $a->{iot_type};
    }
    elsif ( $a->{nested} ne "NO" ) {
        $hash->{table_type} = '嵌套表';
    }
    elsif ( $a->{temporary} ne "N") {
        $hash->{table_type} = "临时表";
    }
    elsif ( $a->{partitioned} eq "YES") {
        $hash->{table_type} = "分区表";
    }
    else {
        $hash->{table_type} = "堆表";
    }
}

=d 以下是运行屏幕显示
[teamsun@TeamWorks tmp]$ perl 8
### $a: {
###       cluster_name => undef,
###       column_name => 'OBJ#',
###       column_position => '1',
###       extents => '102',
###       index_name => 'I_IDL_UB11',
###       index_size => 2097152,
###       index_tablespace_name => 'SYSTEM',
###       index_type => 'NORMAL',
###       iot_type => undef,
###       nested => 'NO',
###       owner => 'SYS',
###       table_name => 'IDL_UB1$',
###       table_size => 260046848,
###       tablespace_name => 'SYSTEM',
###       temporary => 'N'
###     }
Use of uninitialized value in string eq at 1 line 35 (#1)
    (W uninitialized) An undefined value was used as if it were already
    defined.  It was interpreted as a "" or a 0, but maybe it was a mistake.
    To suppress this warning assign a defined value to your variables.
    To help you figure out what was undefined, perl tells you what operation
    you used the undefined value in.  Note, however, that perl optimizes your
    program and the operation displayed in the warning may not necessarily
    appear literally in your program.  For example, "that $foo" is
    usually optimized into "that " . $foo, and the warning will refer to
    the concatenation (.) operator, even though there is no . in your
    program.
=cut

请问各位，为什么对这个HASH VALUE判断老是出错呢？谢谢！

jjqing

很感谢，原来就是因为%hash里面没有'partitioned‘这个KEY，所以才导致这段报错，现在已经修改，使%hash包含了partition，运行已经不报错了。

谢谢！

jjqing

回复 2# q1208c

不好意思，%hash里面没有partitioned这个KEY，所以测试脚本改成如下，我的PERL版本是：This is perl, v5.8.9 built for x86_64-linux

1. #!/usr/bin/perl
   
2. use strict;
   
3. use warnings;
   
4. use diagnostics;
   
5. use Smart::Comments '###';
   
6. 
   
7. my (%hash,$result);
   
8. 
   
9. %hash = (
   
10.     cluster_name => undef,
    
11.     column_name => 'OBJ#',
    
12.     column_position => '1',
    
13.     extents => '102',
    
14.     index_name => 'I_IDL_UB11',
    
15.     index_size => 2097152,
    
16.     index_tablespace_name => 'SYSTEM',
    
17.     index_type => 'NORMAL',
    
18.     iot_type => undef,
    
19.     nested => 'NO',
    
20.     owner => 'SYS',
    
21.     table_name => 'IDL_UB1,
    
22.     table_size => 260046848,
    
23.     tablespace_name => 'SYSTEM',
    
24.     temporary => 'N'
    
25. );
    
26. 
    
27. ### %hash
    
28. push ( @$result, { %hash } );
    
29. ### $result
    
30. 
    
31. 
    
32. foreach my $a ( @{ $result } ) {
    
33.     my $hash;
    
34.     ### $a
    
35.     if ( defined $a->{cluster_name} ) {
    
36.         $hash->{table_type} = 'CLUSTER';
    
37.     }
    
38.     elsif ( defined $a->{iot_type} ) {
    
39.         $hash->{table_type} = $a->{iot_type};
    
40.     }
    
41.     elsif ( $a->{nested} ne "NO" ) {
    
42.         $hash->{table_type} = '嵌套表';
    
43.     }
    
44.     elsif ( $a->{temporary} ne "N") {
    
45.         $hash->{table_type} = "临时表";
    
46.     }
    
47.     else {
    
48.         $hash->{table_type} = "堆表";
    
49.     }
    
50. 
    
51. }
    

复制代码

q1208c

1.    elsif ( $a->{partitioned} eq "YES") {
   
2.         $hash1->{table_type} = "分区表";
   

复制代码

我这里是这段报错.