I have a string "May-20". Is it possible to use Carbon Library to convert the date as "2020-05"?
Any function can covert it?
$date = new DateTime('Aug-20');
echo $date->format('Y-m');
Use the native method of PHP createFromFormat():
Carbon::createFromFormat('!M-y', 'Aug-20')
See the list of available format here:
https://www.php.net/manual/fr/datetime.format.php
If your string can be in non-English languages, see the Carbon method translateTimeString
Try this:
$carbon_date = new Carbon('Aug-20');
echo $carbon_date->format("Y-m");
Same in one line
echo (new Carbon('Aug-20'))->format("Y-m");
Related
I use a config file (type .ini) to save my SQL queries, then i get a query by its key. All work fine, until creating a query with parameters, example :
;the ini file
product_by_cat = select * from products where cat =%s
I use :
config = configparser.ConfigParser()
args= ('cat1')
config.read(path_to_ini_file)
query= config.get(section_where_are_stored_thequeries,key_of_the_query)
complete_query= query%args
I get the error :
TypeError: not all arguments converted during string formatting
So it try to format the string at retrieving the value from the ini file.
Any proposition of my problem.
You can use format function like this
ini file
product_by_cat = select * from products where cat ={}
python:
complete_query= query.format(args)
depending on the versions of ConfigParser (Python 2 or Python 3) you may need to double the % like this or it throws an error:
product_by_cat = select * from products where cat =%%s
Although a better way would be to use the raw version of the config parser, so the % char isn't interpreted
config = configparser.RawConfigParser()
In bash shell, if you hit up or down arrows, the shell will show you your previous or next command that you entered, and you can edit those commands to be new shell commands.
In perl6, if you do
my $name = prompt("Enter name: ");
it will print "Enter name: " and then ask for input; is there a way to have perl6 give you a default value and then you just edit the default to be the new value. E.g.:
my $name = prompt("Your name:", "John Doe");
and it prints
Your name: John Doe
where the John Doe part is editable, and when you hit enter, the edited string is the value of $name.
https://docs.raku.org/routine/prompt does not show how to do it.
This is useful if you have to enter many long strings each of which is just a few chars different from others.
Thanks.
To get the editing part going, you could use the Linenoise module:
zef install Linenoise
(https://github.com/hoelzro/p6-linenoise)
Then, in your code, do:
use Linenoise;
sub prompt($p) {
my $l = linenoise $p;
linenoiseHistoryAdd($l);
$l
}
Then you can do your loop with prompt. Remember, basically all Perl 6 builtin functions can be overridden lexically. Now, how to fill in the original string, that I haven't figure out just yet. Perhaps the libreadline docs can help you with that.
Well by default, programs are completely unaware of their terminals.
You need your program to communicate with the terminal to do things like pre-fill an input line, and it's unreasonable to expect Perl 6 to handle something like this as part of the core language.
That said, your exact case is handled by the Readline library as long as you have a compatible terminal.
It doesn't look like the perl 6 Readline has pre-input hooks setup so you need to handle the callback and read loop yourself, unfortunately. Here's my rough attempt that does exactly what you want:
use v6;
use Readline;
sub prompt-prefill($question, $suggestion) {
my $rl = Readline.new;
my $answer;
my sub line-handler( Str $line ) {
rl_callback_handler_remove();
$answer = $line;
}
rl_callback_handler_install( "$question ", &line-handler );
$rl.insert-text($suggestion);
$rl.redisplay;
while (!$answer) {
$rl.callback-read-char();
}
return $answer;
}
my $name = prompt-prefill("What's your name?", "Bob");
say "Hi $name. Go away.";
If you are still set on using Linenoise, you might find the 'hints' feature good enough for your needs (it's used extensively by the redis-cli application if you want a demo). See the hint callback used with linenoiseSetHintsCallback in the linenoise example.c file. If that's not good enough you'll have to start digging into the guts of linenoise.
Another solution :
Use io-prompt
With that you can set a default value and even a default type:
my $a = ask( "Life, the universe and everything?", 42, type => Num );
Life, the universe and everything? [42]
Int $a = 42
You can install it with:
zef install IO::Prompt
However, if just a default value is not enough. Then it is better you use the approach Liz has suggested.
I am using Apache::Log::Parser to parse Apache log files.
I extracted the date from log file using the following code.
my $parser = Apache::Log::Parser->new(fast=>1);
my $log = $parser->parse($data);
$t = $log->{date};
Now,I tried to use Time::Piece to parse dates, but I'm unable to do it.
print "$t->day_of_month";
But, it's not working. How to use Time::Piece to parse date?
You cannot call methods on objects inside of string interpolation. It will probably output something like this:
Sat Feb 18 12:44:47 2017->day_of_month
Remove the double quotes "" to call the method.
print $t->day_of_month;
Now the output is:
18
Note that you need to create a Time::Piece object with localtime or gmtime if you have an epoch value in your log, or using strptime if the date is some kind of timestamp.
I've seen that there is a constructor which accepts header control parameter
CSVExcelStorage(String delimiter, String multilineTreatmentStr, String eolTreatmentStr, String headerTreatmentStr)
However I haven't found what is the value of "SKIP_INPUT_HEADER" constant.
I dont know why you want the constant value of SKIP_INPUT_HEADER but if your intention is to remove the header during load, then please check the below example
input.csv
Name,Age,Location
a,10,chennai
b,20,banglore
PigScript:(With SKIP_INPUT_HEADER)
REGISTER '/tmp/piggybank.jar';
A = LOAD 'input.csv' USING org.apache.pig.piggybank.storage.CSVExcelStorage(',', 'NO_MULTILINE', 'UNIX', 'SKIP_INPUT_HEADER');
DUMP A;
Output:
(a,10,chennai)
(b,20,banglore)
PigScript:(Without SKIP_INPUT_HEADER)
REGISTER '/tmp/piggybank.jar';
A = LOAD 'input.csv' USING org.apache.pig.piggybank.storage.CSVExcelStorage(',', 'NO_MULTILINE', 'UNIX');
DUMP A;
OutPut:
(Name,Age,Location)
(a,10,chennai)
(b,20,banglore)
I'm working with a legacy system and need to find a way to insert files into a pre-existing Postgres 8.2 bytea column using Perl.
So far my searching has lead me to believe the following:
there is no consensus best approach for this.
lo_import looks promising, but I'm apparently too perl-tarded to get it to work.
I was hoping to do something like the following
my $bind1 = "foo"
my $bind2 = "123"
my $file = "/path/to/file.ext"
my $q = q{
INSERT INTO generic_file_table
(column_1,
column_2,
bytea_column
)
VALUES
(?, ?, lo_import(?))
};
my $sth = $dbh->prepare($q);
$sth->execute($bind1, $bind2, $file);
$sth->finish();`
My script works w/o the lo_import/bytea part. But with it I get this error:
DBD::Pg::st execute failed: ERROR: column "contents" is of type bytea but expression is >of type oid at character 176
HINT: You will need to rewrite or cast the expression.
What I think I'm doing wrong is that I'm not passing the actual binary file to the DB properly. I think I'm passing the file path, but not the file itself. If that's true then what I need to figure out is how to open/read the file into a tmp buffer, and then use the buffer for the import.
Or am I way off base here? I'm open to any pointers, or alternative solutions as long as they work with Perl 5.8/DBI/PG 8.2.
Pg offers two ways to store binary files:
large objects, in the pg_largeobject table, which are referred to by an oid. Often used via the lo extension. May be loaded with lo_import.
bytea columns in regular tables. Represented as octal escapes like \000\001\002fred\004 in PostgreSQL 9.0 and below, or as hex escapes by default in Pg 9.1 and above eg \x0102. The bytea_output setting lets you select between escape (octal) and hex format in versions that have hex format.
You're trying to use lo_import to load data into a bytea column. That won't work.
What you need to do is send PostgreSQL correctly escaped bytea data. In a supported, current PostgreSQL version you'd just format it as hex, bang a \x in front, and you'd be done. In your version you'll have to escape it as octal backslash-sequences and (because you're on an old PostgreSQL that doesn't use standard_conforming_strings) probably have to double the backslashes too.
This mailing list post provides a nice example that will work on your version, and the follow-up message even explains how to fix it to work on less prehistoric PostgreSQL versions too. It shows how to use parameter binding to force bytea quoting.
Basically, you need to read the file data in. You can't just pass the file name as a parameter - how would the database server access the local file and read it? It'd be looking for a path on the server.
Once you've read the data in, you need to escape it as bytea and send that to the server as a parameter.
Update: Like this:
use strict;
use warnings;
use 5.16.3;
use DBI;
use DBD::Pg;
use DBD::Pg qw(:pg_types);
use File::Slurp;
die("Usage: $0 filename") unless defined($ARGV[0]);
die("File $ARGV[0] doesn't exist") unless (-e $ARGV[0]);
my $filename = $ARGV[0];
my $dbh = DBI->connect("dbi:Pg:dbname=regress","","", {AutoCommit=>0});
$dbh->do(q{
DROP TABLE IF EXISTS byteatest;
CREATE TABLE byteatest( blah bytea not null );
});
$dbh->commit();
my $filedata = read_file($filename);
my $sth = $dbh->prepare("INSERT INTO byteatest(blah) VALUES (?)");
# Note the need to specify bytea type. Otherwise the text won't be escaped,
# it'll be sent assuming it's text in client_encoding, so NULLs will cause the
# string to be truncated. If it isn't valid utf-8 you'll get an error. If it
# is, it might not be stored how you want.
#
# So specify {pg_type => DBD::Pg::PG_BYTEA} .
#
$sth->bind_param(1, $filedata, { pg_type => DBD::Pg::PG_BYTEA });
$sth->execute();
undef $filedata;
$dbh->commit();
Thank you to those who helped me out. It took a while to nail this one down. The solution was to open the file and store it. then specifically call out the bind variable that is type bytea. Here is the detailed solution:
.....
##some variables
my datum1 = "foo";
my datum2 = "123";
my file = "/path/to/file.dat";
my $contents;
##open the file and store it
open my $FH, $file or die "Could not open file: $!";
{
local $/ = undef;
$contents = <$FH>;
};
close $FH;
print "$contents\n";
##preparte SQL
my $q = q{
INSERT INTO generic_file_table
(column_1,
column_2,
bytea_column
)
VALUES
(?, ?, ?)
};
my $sth = $dbh->prepare($q);
##bind variables and specifically set #3 to bytea; then execute.
$sth->bind_param(1,$datum1);
$sth->bind_param(2,$datum2);
$sth->bind_param(3,$contents, { pg_type => DBD::Pg::PG_BYTEA });
$sth->execute();
$sth->finish();