So I am attempting to connect to a database on an end device from one of my servers, however I'm getting the following error:
Can't connect to data source '<user>' because I can't work out what driver to use (it doesn't seem to contain a 'dbi:driver:' prefix and the DBI_DRIVER env var is not set) at <script> line 18
My lines of code are the following. I removed some private information of course.
my $sHDS = shift || "<host>";
my #rows;
my $cust = '<customer name>';
my $dsn = 'dbi:Sybase:' . $sHDS;
my $user = '<user>';
my $pass = '<password>';
my $hDb = DBI::connect($dsn, $user, $pass)
or die "Can not connect to ICM Database $DBI::errstr";
Anyone see where I am going wrong?
The correct call has the format
DBI->connect($dsn, $user, $password)
which is subtly but significantly different from
DBI::connect($dsn, $user, $password)
The first call is equivalent to the call
DBI::connect( 'DBI', $dsn, $user, $password )
and the connect function in DBI actually expects your dsn to be specified in the 2nd argument it receives.
Related
I have already connected MySQL to the database but the problem is that
I have some problems with inserting Data from Perl to Mysql.
The error that pops out is:
Use of uninitialized value in concatenation (.) or string at ./etl_server_info.pl line 204, (Which is the connection of the database )
DBD::mysql::st execute failed: called with 1 bind variables when 0 are needed at ($stmt->execute($sql);)
sub insert_record(){
my($data,$db_config)=#_;
my $result = -1; # -1 fail; 0 - succ
# connect to db
# connect to MySQL database
my $dsn = "DBI:mysql:database=".$db_config->{'Top_Data'}.";host=".$db_config->{'127.0.0.1'}.";port=".$db_config->{'3306'};
my $username = $db_config->{'username'};
my $password = $db_config->{'password'};
my %attr = (PrintError=>0,RaiseError=>1 );
my $dbh = DBI->connect($dsn,$username,$password,\%attr) or die $DBI::errstr;
print "We Have Successfully Connected To The Database \n";
# prepare sql statement
# execute insert
my $sql = 'insert into Top(Load_Average, CPU_us, CPU_id, CPU-wa, CPU_hi, CPU_si, CPU_st, Swap_Total, Swap_Free, Swap_Used, Memory_Total, Memeory_Free, Memory_Used, Memory_Buff, Date) values(float,float,float,float,float,float,float,float,varchar,varchar,varchar,varchar,varchar,varchar,date)';
my $stmt =$dbh->prepare($sql) or die "Its A Fail" . $dbh->errstr();
$stmt->execute($sql);
$stmt->finish();
$dbh->disconnect();
$result = 0;
return($result);
Your use of the $db_config variable looks suspicious to me. Either your config hash is strange, or you're using values instead of keys.
You haven't shown us where $db_config is set up, but I'd guess it looks something like this:
$db_config = {
name => 'Top_Data',
host => '127.0.0.1',
port => 3306,
username => 'someone',
password => 'a secret',
};
And then you would use it like this:
my $dsn = "DBI:mysql:database=".$db_config->{name}.";host=".$db_config->{host}.";port=".$db_config->{port};
Notice that I've used the key names (name, host and port) instead of the values (Top_Data, 127.0.0.1 and 3306).
I'll also point out that you can simplify this slightly by using Perl's ability to expand variables inside a double-quoted string.
my $dsn = "DBI:mysql:database=$db_config->{name};host=$db_config->{host};port=$db_config->{port}";
There's another problem later on, with your SQL statement.
my $sql = 'insert into Top(Load_Average, CPU_us, CPU_id, CPU-wa, CPU_hi,
CPU_si, CPU_st, Swap_Total, Swap_Free, Swap_Used, Memory_Total,
Memeory_Free, Memory_Used, Memory_Buff, Date)
values(float,float,float,float,float,float,float,float,
varchar,varchar,varchar,varchar,varchar,varchar,date)';
The values that you should be inserting are the actual data items. So where you have the strings "float", "varchar" or "date", you should actually have data items (a floating-point number, a string or a date).
Finally, having prepared your statement, you don't need to pass it to the execute() method. You should, however, look at using bind points in your SQL and passing your actual data items to the execute() call
I have connected to one MySQL database which have been hosted in a remote server in Perl. Now I am trying to execute a select statement on a table in subject.pl file using Perl command line. The code is
#!/usr/bin/perl
use DBI;
use strict;
# Connected to mysql audit database in dev server
my $dsn = 'DBI:mysql:Driver={mysql}';
my $host = 'dev-mysql.learn.local';
my $database = 'subject';
my $user = 'testUser';
my $auth = 'testPassword';
my $dbh = DBI->connect("$dsn;host=$host;Database=$database",$user,$auth) or die "Database connection not made: $DBI::errstr";
# Prepare query
my $sql = "SELECT
subject_id
,subject_value
FROM
subject";
my $sth = $dbh->prepare($sql);
#Execute the statement
$sth->execute() or die "Unable to execute".$sth->errstr;
while (my #row = $sth->fetchrow_array()) {
my ($subject_id, $subject_value ) = #row;
print "$subject_id,$subject_value,$subject_db_field\n";
}
$sth->finish();
I am getting error at line $sth->execute() or die "Unable to execute".$sth->errstr;
The error message is Unable to execute at D:\Demo\perl_demo\subject.pl line 24.
But when I am printing the $dbh variable, its giving the result like DBI::db=HASH(0x1ca7884). So I guess the connection is establishing properly.
Please help me to fix this issue as I am completely new in Perl scripting.
Check for errors on prepare,
my $sth = $dbh->prepare($sql) or die $dbh->errstr;
This question already has an answer here:
Win 64 Strawberry Perl DBI no error reporting bug still not fixed?
(1 answer)
Closed 9 years ago.
I'm executing a script similar to the following and when there is a failed operation, the execute function returns an undefined value, so I can detect that it failed, so that's good. However, I find that err() and errstr don't return anything. I was expecting to get an error code and an error message, respectively. What I am doing wrong? Thanks for any info.
use DBI;
$db="foobar";
$host="localhost";
$user="root";
$password="mypassword";
my $dbh = DBI->connect("DBI:mysql:database=$db:host=$host",
$user, $password) or die "Oops: $DBI::errstr\n";
my $sth = $dbh->prepare("invalid sql");
my $returnval = $sth->execute();
my $errcode = $sth->err();
my $errstring = $sth->errstr;
print "returnval=$returnval, errcode=$errcode, errstring=$errstring\n";
Output:
returnval=, errcode=, errstring=
I am working with Strawberry Perl (32-bit) on a 64-bit Windows 7 system. (I am working with 32-bit version because of another module I am using won't work with the 64-bit version.) perl.exe --version says: "This is perl 5, version 16, subversion 3 (v5.16.3) built for MSWin32-x86-multi-thread"
DBI->connect("DBI:mysql:database=$db:host=$host",
$user, $password) or die "Oops: $DBI::errstr\n";
it should be like, try this it may work
DBI->connect("DBI:mysql:$db:$host:$portNumber",
$user, $password) or die "Oops: $DBI::errstr\n";
I have used ActivePerl, we need to pass the mysql port number by default it will be 3306.
DBI->connect("DBI:mysql:$db:$host:3306",
$user, $password) or die "Oops:errstr $! \n";
err and errstr are methods of the DBI module, not the statement handles. You should say
my $errcode = $dbh->err();
my $errstring = $dbh->errstr; # or DBI->errstr or $DBI::errstr
Something is wrong with this code.
#!/use/bin/perl
use strict;
use warnings;
use Frontier::Daemon;
use DBI;
sub credentials {
my ($username, $password) = #_;
my $tablename = "users";
my $user = "db_user";
my $pw = "db_pass";
$dbh = DBI->connect('DBI:mysql:database;host=localhost', $user, $pw, {RaiseError => 1});
$sql = "SELECT username, password FROM $tablename";
$sth = $dbh->prepare($sql);
$sth->execute or die "SQL Error: $DBI::errstr\n";
if ($sth->rows > 0) {
$login_response = "Login Successful";
} else {
$login_response = "Invalid Credentials";
return {'login' => $login_response};
die();
}
}
$methods = {'login.credentials' => \&credentials,};
Frontier::Daemon->new(LocalPort => 8080, methods => $methods)
or die "Couldn't start HTTP server: $!";
This is another problem with your code - you're not doing anything with the supplied username and password. You need to add a where clause to your SQL statement, so:
my $sql = 'SELECT * FROM users WHERE username = ? AND password = ? ';
my $sth = $dbh->prepare($sql);
$sth->execute($username, $password);
However, given that your example is selecting all records from the 'users' table, I'd have thought that credentials() would at least be returning some rows. However, I'm afraid that I've not used Frontier::Daemon in the past, so I'm not able to help on that front.
I also can't see how this code would work given that you are using strictures. $dbh, $sql, $sth and $login_response haven't been declared. So make sure that you're using 'my' in the right places - as per my example above.
To fix the problems you mentioned with returning the correct string - the logic in your if statement isn't quite right. You are returning the string 'Login Successful' when there's a successful login and the hashref { login => $login_response } when no user could be found.
I think the confusion arose from the layout of the braces. I must stress that you try and indent you code properly, which will make it much more readable to yourself and other developers when debugging and maintaining the code in the future.
The following logic should do the job.
if($sth->rows > 0){
return "Login Successful";
}
return "Invalid Credentials";
How do I call MySQL stored procedures from Perl? Stored procedure functionality is fairly new to MySQL and the MySQL modules for Perl don't seem to have caught up yet.
MySQL stored procedures that produce datasets need you to use Perl DBD::mysql 4.001 or later. (http://www.perlmonks.org/?node_id=609098)
Below is a test program that will work in the newer version:
mysql> delimiter //
mysql> create procedure Foo(x int)
-> begin
-> select x*2;
-> end
-> //
perl -e 'use DBI; DBI->connect("dbi:mysql:database=bonk", "root", "")->prepare("call Foo(?)")->execute(21)'
But if you have too old a version of DBD::mysql, you get results like this:
DBD::mysql::st execute failed: PROCEDURE bonk.Foo can't return a result set in the given context at -e line 1.
You can install the newest DBD using CPAN.
There's an example in the section on Multiple result sets in the DBD::mysql docs.
#!/usr/bin/perl
# Stored Proc - Multiple Values In, Multiple Out
use strict;
use Data::Dumper;
use DBI;
my $dbh = DBI->connect('DBI:mysql:RTPC;host=db.server.com',
'user','password',{ RaiseError => 1 }) || die "$!\n";
my $sth = $dbh->prepare('CALL storedProcedure(?,?,?,?,#a,#b);');
$sth->bind_param(1, 2);
$sth->bind_param(2, 1003);
$sth->bind_param(3, 5000);
$sth->bind_param(4, 100);
$sth->execute();
my $response = $sth->fetchrow_hashref();
print Dumper $response . "\n";
It took me a while to figure it out, but I was able to get what I needed with the above. if you need to get multiple return "lines" I'm guessing you just...
while(my $response = $sth->fetchrow_hashref()) {
print Dumper $response . "\n";
}
I hope it helps.
First of all you should be probably connect through the DBI library and then you should use bind variables. E.g. something like:
#!/usr/bin/perl
#
use strict;
use DBI qw(:sql_types);
my $dbh = DBI->connect(
$ConnStr,
$User,
$Password,
{RaiseError => 1, AutoCommit => 0}
) || die "Database connection not made: $DBI::errstr";
my $sql = qq {CALL someProcedure(1);} }
my $sth = $dbh->prepare($sql);
eval {
$sth->bind_param(1, $argument, SQL_VARCHAR);
};
if ($#) {
warn "Database error: $DBI::errstr\n";
$dbh->rollback(); #just die if rollback is failing
}
$dbh->commit();
Mind you i haven't tested this, you'll have to lookup the exact syntax on CPAN.
Hi, similar to above but using SQL exec. I could not get the CALL command to work. You will need to fill in anything that is within square brackets and remove the square brackets.
use DBI;
#START: SET UP DATABASE AND CONNECT
my $host = '*[server]*\\*[database]*';
my $database = '*[table]*';
my $user = '*[user]*';
my $auth = '*[password]*';
my $dsn = "dbi:ODBC:Driver={SQL Server};Server=$host;Database=$database";
my $dbh = DBI->connect($dsn, $user, $auth, { RaiseError => 1 });
#END : SET UP DATABASE AND CONNECT
$sql = "exec *[stored procedure name]* *[param1]*,*[param2]*,*[param3]*;";
$sth = $dbh->prepare($sql);
$sth->execute or die "SQL Error: $DBI::errstr\n";