At 10:30 AM -0700 6/29/01, Rajanath Tadikonda wrote:
>Hi,
>I executed the code in Windows environment and it is returning number of
>rows with the help of
>$sth->rows
>or
>$rv=$sth->execute;
>These two statements are returning number of rows returned without any
>problem in Windows Enviroment but in the case of Unix (Sun OS 5.8 we are
>using) it is returning number of rows as 0E0 and there are rows in the Table
>that is very annoying .
perldoc DBI says, first:
For `SELECT' statements, execute simply "starts" the
query within the database engine. Use one of the fetch
methods to retreive the data after calling `execute'.
The `execute' method does not return the number of
rows that will be returned by the query (because most
databases can't tell in advance), it simply returns a
true value.
And, second:
`rows'
$rv = $sth->rows;
Returns the number of rows affected by the last row
affecting command, or -1 if the number of rows is not
known or not available.
Generally, you can only rely on a row count after a
non-`SELECT' `execute' (for some specific operations
like `UPDATE' and `DELETE'), or after fetching all the
rows of a `SELECT' statement.
For `SELECT' statements, it is generally not possible
to know how many rows will be returned except by
fetching them all. Some drivers will return the
number of rows the application has fetched so far, but
others may return -1 until all rows have been fetched.
So use of the `rows' method or `$DBI::rows' with
`SELECT' statements is not recommended.
So I'd say that according to the documentation, you're taking
your chances by writing your code as you are. Count the rows
yourself, or perhaps use a method such as selectall_arrayref()
that returns a result from which you can determine the number of
rows, or else perhaps issue a select COUNT(*) query...
>
>Rajanath
>----- Original Message -----
>From: "Mark Thornber" <[EMAIL PROTECTED]>
>To: "Rajanath Tadikonda" <[EMAIL PROTECTED]>
>Cc: "DBI USERS" <[EMAIL PROTECTED]>
>Sent: Friday, June 29, 2001 1:24 AM
>Subject: Re: Returned value error
>
>
>> Rajanath,
>>
>> Look in the fine perldoc for DBI. "0E0" is TRUE and no error but zero
>> rows.
>>
>>
>> --MarkT
>>
>> Rajanath Tadikonda wrote:
>> >
>> > Hi all ,
>> > I am trying to get a returned value in $rv and based on query using
>oracle
>> > ..
>> > This query is returning properly the number of records retr'ved
>without
>> > any problem
>> > but if I try the same code in Unix it is returning "0E0";
>> >
>> > I will appreciate if any one with similar experiance
>> >
>> > Thank
>> > Rajanath
>> > #!/usr/bin/perl
>> > use DBI qw(:sql_types);
>> >
>> > my %dbx=getDetails();
>> > my %attr = (PrintError => 0,RaiseError =>0,AutoCommit=>0);
>> > my $rv=0;
>> > $xctr++;
>> >
>> > my($usr,$pass,$drv,$connect_string) =
>> > ($dbx{DB_USERNAME},$dbx{DB_PASSWD},$dbx{
>> >
>> > my ($dbh,$status1,$err)=&oraon($usr,$pass,$drv,$connect_string);
>> >
>> > if(!$status1)
>> > {
>> > &beta_error_page($err);
>> >
>> > exit(0);
>> > }
>> >
>> > $dbh->{LongReadLen}=4096*1024;
>> >
>> > my $sql2="select req_id,user_id,prog_id,file_data,status from
>> > fms_contact_impo
>> >
>> > my $sth=$dbh->prepare($sql2);
>> >
>> > if(!$sth)
>> > {
>> > &beta_error_page($DBI::errstr);
>> >
>> > exit(0);
>> > }
>> >
>> > my $rv=$sth->execute();
>> > print " Returned values is $rv \n";
>> > exit(0);
>>
--
Paul DuBois, [EMAIL PROTECTED]
