I'm reading from a csv file and after grouping those datas I'm doing a count operation . Is there any way to store the datas into a folder name bad if the count is 0 and to good if the count is > 0 . I tried with the below code but it is not happening .
CODE :
STORE countVal INTO '/user/cloudera/good' IF countVal > 0 ;
USE function SPLIT. Refer :
https://pig.apache.org/docs/r0.7.0/piglatin_ref2.html#SPLIT
SPLIT A INTO X IF f1<7, Y IF f2==5, Z IF (f3<6 OR f3>6);
There are a couple of ways this :
1)Use the split function to perform the split based on the criteria.
SPLIT data into good if count>0, bad if (count==0);
2)Use a FOREACH loop to separate the data based on a criteria, using a BinCond operator.
X = FOREACH A GENERATE , data, (count>0?"good":"bad");
Related
I have multiple tables like as follows in BigQuery:
PROJECT_NAME.DATA_SET_NAME.TABLENAME0
PROJECT_NAME.DATA_SET_NAME.TABLENAME1
PROJECT_NAME.DATA_SET_NAME.TABLENAME2
PROJECT_NAME.DATA_SET_NAME.TABLENAME3
PROJECT_NAME.DATA_SET_NAME.TABLENAME4
...
I want to empty some of these tables via a loop but don't know how to call the CONCAT in FROM clause:
DECLARE count INT64 DEFAULT 0;
WHILE count < 1000 Do
DELETE FROM CONCAT('PROJECT_NAME.DATA_SET_NAME.TABLENAME' , count ) WHERE TRUE;
SET count = count + 1;
END WHILE
But it's not working, it says I cannot use CONCAT in FROM part.
Anyone knows how should I do it?
Thanks
This is not currently possible in BigQuery, unless you script it outside BigQuery.
There's an open feature request, that you should subscribe to - to indicate interest and follow any new developments:
https://issuetracker.google.com/issues/142531516
I am very new to Pig , so facing some issues while trying to perform very basic processing in Pig.
1- Load that file using Pig
2- Write a processing logic to filter records based on Date , for example the lines have 2 columns col_1 and col_2 ( assume the columns are chararray ) and I need to get only the records which are having 1 day difference between col_1 and col_2.
3- Finally store that filtered record in Hive table .
Input file ( tab separated ) :-
2016-01-01T16:31:40.000+01:00 2016-01-02T16:31:40.000+01:00
2017-01-01T16:31:40.000+01:00 2017-01-02T16:31:40.000+01:00
When I try
A = LOAD '/user/inp.txt' USING PigStorage('\t') as (col_1:chararray,col_2:chararray);
The result I am getting like below :-
DUMP A;
(,2016-01-03T19:28:58.000+01:00,2016-01-02T16:31:40.000+01:00)
(,2017-01-03T19:28:58.000+01:00,2017-01-02T16:31:40.000+01:00)
Not sure Why ?
Please can some one help me in this how to parse tab separated file and how to covert that chararray to Date and filter based on Day difference ?
Thanks
Convert the columns to datetime object using ToDate and use DaysBetween.This should give the difference and if the difference == 1 then filter.Finally load it hive.
A = LOAD '/user/inp.txt' USING PigStorage('\t') as (col_1:chararray,col_2:chararray);
B = FOREACH A GENERATE DaysBetween(ToDate(col_1,'yyyy-MM-dd HH:mm:ss'),ToDate(col_2,'yyyy-MM-dd HH:mm:ss')) as day_diff;
C = FILTER B BY (day_diff == 1);
STORE C INTO 'your_hive_partition' USING org.apache.hive.hcatalog.pig.HCatStorer();
I want to divide a single row into multiple row on the basis of a field in pig.
Example:
Consider one of the row in movie Data Set as follows:
(31807, Dot the I (2003), Drama|Film-Noir|Thriller)
each field is separated by ','.
Desired Output is as follows in 3 different rows:
31807,Dot the I (2003),Drama
31807,Dot the I (2003),Film-Noir
31807,Dot the I (2003),Thriller
Can anyone please help me to get the desired output in pig.
The below logic will help you .
/* Input
(31807,Dot the I (2003),Drama|Film-Noir|Thriller)
*/
list = LOAD '/user/cloudera/movies.txt' USING PigStorage(',') AS(id:int,name:chararray,generes:chararray);
list_each = FOREACH list GENERATE id,name, flatten(TOKENIZE(generes,'|'));
dump list_each;
/* Output
(31807,Dot the I (2003),Drama)
(31807,Dot the I (2003),Film-Noir)
(31807,Dot the I (2003),Thriller)
*/
I am new to Pig Latin.
I want to extract all lines that match a filter criteria (have a word "line_token" ) from log files and then from these matching lines extract two different fields meeting two separate field match criteria . Since the lines aren't structured well I am loading them as a char array.
When I try to run the following code - I get an error
"Invalid resource schema: bag schema must have tuple as its field"
I have tried to perform an explicit cast to a tuple but that does not work
input_lines = LOAD '/inputdir/' AS ( line:chararray);
filtered_lines = FILTER input_lines BY (line MATCHES '.*line_token1.*' );
tokenized_lines = FOREACH filtered_lines GENERATE FLATTEN(TOKENIZE(line)) AS tok_line;
my_wordbag = FOREACH tokenized_lines {
word1 = FILTER tok_line BY ( $0 MATCHES '.*word_token1.*' ) ;
word2 = FILTER tok_line BY ( $0 MATCHES '.*word_token1.*' ) ;
GENERATE word1 , word2 as my_tuple ;
-- I also tried --> GENERATE (word1 , word2) as my_tuple ;
}
dump my_wordbag;
I suppose I am taking a very wrong approach.
Please note - my logs aren't structured well - so I cant mend the way I load
Post loading and initial filtering for lines of interest ( which is straightforward) - I guess I need to do something different rather than tokenize line and iterate through fields trying to find fields.
Or maybe I should use joins ?
Also if I know the structure of line beforehand well as all text fields, then will loading it differently ( not as a chararray) make it an easier problem ?
For now I made a compromise - I added a extra filter clause in my original - line filter and settled for picking just one field from line. When I get back to it I will try with joins and post that code ... - here's my working code that gets me a useful output - but not all that I want.
-- read input lines from poorly structured log
input_lines = LOAD '/log-in-dir-in-hdfs' AS ( line:chararray) ;
-- Filter for line filter criteria and date interested in passed as arg
filtered_lines = FILTER input_lines BY (
( line MATCHES '.*line_filter1*' )
AND ( line MATCHES '.*line_filter2.*' )
AND ( line MATCHES '.*$forDate.*' )
) ;
-- Tokenize every line
tok_lines = FOREACH filtered_lines
GENERATE TOKENIZE(line) AS tok_line;
-- Pick up specific field frm tokenized line based on column filter criteria
fnames = FOREACH tok_lines {
fname = FILTER tok_line BY ( $0 MATCHES '.*field_selection.*' ) ;
GENERATE FLATTEN(fname) as nnfname;
}
-- Count occurances of that field and store it with field name
-- My original intent is to store another field name as well
-- I will do that once I figure how to put both of them in a tuple
flgroup = FOREACH fnames
GENERATE FLATTEN(TOKENIZE((chararray)$0)) as cfname;
grpfnames = group flgroup by cfname;
readcounts = FOREACH grpfnames GENERATE COUNT(flgroup), group ;
STORE readcounts INTO '/out-dir-in-hdfs';
As I understand, after the FLATTEN operation, you have single line (tok_line) in each row and you want to extract 2 words from each line. REGEX_EXTRACT will help you achieve this. I'm not a REGEX expert so will leave writing the REGEX part up to you.
data = FOREACH tokenized_lines
GENERATE
REGEX_EXTRACT(tok_line, <first word regex goes here>) as firstWord,
REGEX_EXTRACT(tok_line, <second word regex goes here>) as secondWord;
I hope this helps.
You must refer to the alias, not the column.
So:
word1 = FILTER tokenized_lines BY ( $0 MATCHES '.*word_token1.*' ) ;
word1 and word2 are going to be aliases as well, not columns.
How do you need the output to look like?
I am trying to convert the below Hive statement to Pig:
max(substr(case when url like 'http:%' then '' else url end,1,50))
My pig statement for the above is:
url_group = GROUP data by (uid);
max_substr_url= FOREACH url_group generate SUBSTRING(MAX(((Coalesce(data.url) matches '.*http:%.*') ? '' : Coalesce(data.url))), 0, 49);
For some of the data, the url can be null. So I have written a pig UDF called Coalesce(String) which returns an empty string if the data is either null or empty. If the data is not null or not empty it returns the string back.
The above pig statement is giving me lot of trouble and tried n different options/ways but nothing worked. Anyone got any ideas on how to implement this? Please help me.
Thanks in advance
You are going to want to use a nested FOREACH so that you can do the substring transformation on each tuple in the data bag then take the MAX of the transformed bag.
A = GROUP data by (uid);
B = FOREACH url_group {
-- MAX needs a one column bag
transformed = FOREACH data
GENERATE SUBSTRING((Coalesce(url) matches '.*http:.*' ? '' : Coalesce(url)), 0, 49);
GENERATE group AS uid, MAX(transformed) ;
}