I'm trying to analyze how postgreSQL parse a query, and after some postgreSQL source code tracing with embedding printf() here and there, I've known that the query will be parsed into raw parse tree with raw_parser, which located in file parser.c.
The strange thing is, I've already embedded a printf() dummy in the raw_parser, and after re-installing the postgreSQL and execute a query, my printf() dummy is not printed to the screen!
Can anybody please help me, where I went wrong?
Thanks in advance :D
if you use printf(stderr, "...."), then you can find result in server log. Don't forget - you are not work with server directly. For debugging purposes there are a elog function - it's like printf for client application:
elog(NOTICE, "some text");
a format string is same like printf's format - but you must to remember, PostgreSQL uses a different formats than glibc - so you can to show only integer or float variables. String variables uses different format than is C zero finished string.
Related
I've got a dataflow with a csv file as source. The column NewPositive is a string and it contains numbers formatted in European style with a dot as thousand seperator e.g 1.019 meaning 1019
If I use the function toInteger to convert my NewPositive column to an int via toInteger(NewPositive,'#.###','de'), I only get the thousand cipher e.g 1 for 1.019 and not the rest. Why? For testing I tried creating a constant column: toInteger('1.019','#.###','de') and it gives 1019 as expected. So why does the function not work for my column? The column is trimmed and if I compare the first value with equality function: equals('1.019',NewPositive) returns true.
Please note: I know it's very easy to create a workaround by toInteger(replace(NewPositive,'.','')), but I want to learn how to use the toInteger function with the locale and format parameters.
Here is sample data:
Dato;NewPositive
2021-08-20;1.234
2021-08-21;1.789
I was able to repro this and probably looks to be a bug to me . I have reported this to the ADF team , will let you know once I hear back from them . You already have a work around please go ahead that to unblock yourself .
I'm trying to find a possible way to convert PSS/E native .raw files to Pandapower format.
My objective is to take advantage of the network plotting capabilities that are available in Pandapower.
For that, I have to first be able to load my grid data into Pandapower.
For that, I have to somehow bridge the gap between PSSE .raw to Pandapower.
Literature says that a possible way of doing this is by using the 'psse2mpc' function available in Matpower.
I've tried to use it but I get the following error message:
(quote)
>> psse2mpc('RED1523.raw')
Reading file 'RED1523.raw' ............................................. done.
Splitting into individual lines ...error: regexp: the input string is invalid UTF-8
error: called from
psse_read at line 60 column 9
psse2mpc at line 68 column 21
(unquote)
I'was informed that maybe I should save my .raw file (natively generated with a PSSE/E v33 version) into an older .raw format (corresponding to previous PSS/E versions).
I've tried this as well but still have the same error message.
Apart from getting this error which so far impedes to reach my objective, I've been unable to guess the Pandapower "equivalent .raw" structure. Does anybody know how this input structure looks like in Pandapower?
If I would know how Pandapower needs to get the input data, I could even try to code a taylor-made python script that converts my .raw file into whatever is required from Pandapower.
If somebody could help me to get out of this labyrinth I would be most gratefull !!!
Thanks.
Eneko.
You need to check your .raw file to enter the other Inputs of the psse2mpc function. For instance, if I have the case39.raw file and I want to convert it to matpower format like case39mpc.m, then I must enter something like this:
psse2mpc ('case39.raw', 'case39mpc.m', '1', '29')
I have a Python script that runs a pgSQL file through SQLAlchemy's connection.execute function. Here's the block of code in Python:
results = pg_conn.execute(sql_cmd, beg_date = datetime.date(2015,4,1), end_date = datetime.date(2015,4,30))
And here's one of the areas where the variable gets inputted in my SQL:
WHERE
( dv.date >= %(beg_date)s AND
dv.date <= %(end_date)s)
When I run this, I get a cryptic python error:
sqlalchemy.exc.ProgrammingError: (psycopg2.ProgrammingError) argument formats can't be mixed
…followed by a huge dump of the offending SQL query. I've run this exact code with the same variable convention before. Why isn't it working this time?
I encountered a similar issue as Nikhil. I have a query with LIKE clauses which worked until I modified it to include a bind variable, at which point I received the following error:
DatabaseError: Execution failed on sql '...': argument formats can't be mixed
The solution is not to give up on the LIKE clause. That would be pretty crazy if psycopg2 simply didn't permit LIKE clauses. Rather, we can escape the literal % with %%. For example, the following query:
SELECT *
FROM people
WHERE start_date > %(beg_date)s
AND name LIKE 'John%';
would need to be modified to:
SELECT *
FROM people
WHERE start_date > %(beg_date)s
AND name LIKE 'John%%';
More details in the pscopg2 docs: http://initd.org/psycopg/docs/usage.html#passing-parameters-to-sql-queries
As it turned out, I had used a SQL LIKE operator in the new SQL query, and the % operand was messing with Python's escaping capability. For instance:
dv.device LIKE 'iPhone%' or
dv.device LIKE '%Phone'
Another answer offered a way to un-escape and re-escape, which I felt would add unnecessary complexity to otherwise simple code. Instead, I used pgSQL's ability to handle regex to modify the SQL query itself. This changed the above portion of the query to:
dv.device ~ E'iPhone.*' or
dv.device ~ E'.*Phone$'
So for others: you may need to change your LIKE operators to regex '~' to get it to work. Just remember that it'll be WAY slower for large queries. (More info here.)
For me it's turn out I have % in sql comment
/* Any future change in the testing size will not require
a change here... even if we do a 100% test
*/
This works fine:
/* Any future change in the testing size will not require
a change here... even if we do a 100pct test
*/
I have an MS SQL Server 2008 Database, from which I am fetching data using perl DBD::Sybase module. But there are some special characters in the DB, like the Copyright symbol, Trademark symbol etc., which are not getting imported properly. Perl seems to change all of these special characters to a Question mark character. Is there a way to fix this?
I have tried specifying charset=utf8 in the connection string. The doc mentions a syb_enable_utf8 (bool) setting, but whenever I try that, I get an error:
Can't locate object method "syb_enable_utf8" via package "DBI::db"
One solution I found was this:
use Encode qw(encode_utf8);
Then, wherever you are writing data to a file or anywhere else, use Encode::encode_utf8($data);
where $data is the column/value which you have fetched from MSSQL.
I don't use DBD::Sybase but a) I use a lot of other DBDs and b) I am currently collecting information about unicode support in DBDs. According to the pod you need at least OpenClient 15.x when using syb_enable_utf8. Are you using 15.x or later? Perhaps syb_enable_utf8 is not defined if your client is less than 15.x or perhaps you have too old a version of DBD::Sybase. Unfortunately I cannot see from the Changes file when syb_enable_utf8 was added.
However, when you say "can't locate method" I think that is a clue as syb_enable_utf8 is not a method, it is an attribute (it is under Sybase Specific Attributes) in the pod. So you need to add it to your connect call or set it via a connection handle like this:
my $h = DBI->connect("dbi:Sybase:something","user","password", {syb_enable_utf8 => 1});
or
$h->{syb_enable_utf8} = 1;
You should also read the bits in the pod describing what happens when syb_enable_utf8 is set as it appears from the documents it only applies to UNIVARCHAR, UNICHAR, and UNITEXT columns.
Lastly, you need to ensure you insert the data correctly in the first place. I'd guess if it is not inserted from Perl with syb_enable_utf8 and charset=utf8 and your data is not proper unicode characters in Perl before you insert you'll get garbage back.
The comment Raze2dust made had nothing to do with your issue but is worth heeding if you are going to write the data retrieved from your database elsewhere. Just remember to decode any data input to your script and encode any data output.
I'm in a web scripting class, and honestly and unfortunately, it has come second to my networking and design and analysis classes. Because of this I find I encounter problems that may be mundane but can't find the solution to it easily.
I am writing a CGI form that is supposed to work with a MySQL DB. I can insert and delete into the DB just fine. My problem comes when querying the DB.
My code compiles fine and I don't get errors when trying to "display" the info in the DB through the browser but the data and text doesn't in fact display. The code in question is here:
print br, 'test';
my $dbh = DBI->connect("DBI:mysql:austinc4", "*******", "*******", {RaiseError => 1} );
my $usersstatement = "select * from users";
my $projstatment = "select * from projects";
# Get the handle
my $userinfo = $dbh->query($usersstatement);
my $projinfo = $dbh->query($projstatement);
# Fetch rows
while (#userrow = $userinfo->fetchrow()) {
print $userrow[0], br;
}
print 'end';
This code is in an if statement that is surrounded by the print header, start_html, form, /form, end_html. I was just trying to debug and find out what was happening and printed the statements test and end. It prints out test but doesn't print out end. It also doesn't print out the data in my DB, which happens to come before I print out end.
What I believe I am doing is:
Connecting to my DB
Forming a string the contains the command/request to the DB
Getting a handle for my query I perform on the DB
Fetching a row from my handle
Printing the first field in the row I fetched from my table
But I don't see why my data wouldn't print out as well as the end text. I looked in DB and it does in fact contain data in the DB and the table that I am trying to get data from.
This one has got me stumped, so I appreciate any help. Thanks again. =)
Solution:
I was using a that wasn't supported by the modules I was including. This leads me to another question. How can I detect errors like this? My program does in fact compile correctly and the webpage doesn't "break". Aside from me double checking that all the methods I do use are valid, do I just see something like text not being displayed and assume that an error like this occurred?
Upon reading the comments, the reason your program is broken is because query() does not execute an SQL query. Therefore you are probably calling an undefined subroutine unless this is a wrapper you have defined elsewhere.
Here is my original posting of helpful hints, which still apply:
I hope you have use CGI, use DBI, etc... and use CGI::Carp and use strict;
Look in /var/log/apache2/access.log or error.log for the bugs
Realize that the first thing a CGI script prints MUST be a valid header or the web server and browser become unhappy and often nothing else displays.
Because of #3 print the header first BEFORE you do anything, especially before you connect to the database where the script may die or print something else because otherwise the errors or other messages will be emitted before the header.
If you still don't see an error go back to #2.
CGIs that use CGI.pm can be run from a command line in a terminal session without going through the webserver. This is also a good way to debug.