Loading data using Hive Sed command - hadoop

I Have my data in this format.
"123";"mybook1";"2002";"publisher1";
"456";"mybook2;the best seller";"2004";"publisher2";
"789";"mybook3";"2002";"publisher1";
the fields are enclosed in "" and are delimited by ; Also the book name may contain ';' in between.
Can you tell me how to load this data from file to hive table
the below query which i am using now obviously not working ;
create table books (isbn string,title string,year string,publisher string) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\;'
if possible i want the userid and year fields to be stored as Int. Please help
Also i dont want to use regexserde command.
how can i use sed command from unix to clean the data and get my output.
i tried to learn about sed command and found the replace option. So i can remove the " double quotations. But how can i handle the extra ; semi colon which comes in the middle of the data
Please help

I think you can preprocess with sed and then use the MetadataTypedColumnsetSerDe WITH SERDEPROPERTIES
sed -r ':a; s/^([^"]*("[^"]*"[^"]*)*);/\1XXXXX/g; t a; s/;/ /g; s/XXXXX/;/g' file
This sed matches the quote pairs to avoid processing what is between quotes putting a placeholder for the semicolons outside of quoted text. Afterward it removes the ;'s from the book title text and replaces them w/a space and puts back the semicolons that are outside quotes.
See here for more how to load data using Hive including an example of MetadataTypedColumnsetSerDe WITH SERDEPROPERTIES:
https://svn.apache.org/repos/asf/hive/trunk/serde/README.txt

create external table books (isbn int,title string,year int,publisher string)
row format SERDE 'org.apache.hadoop.hive.serde2.OpenCSVSerde' WITH
SERDEPROPERTIES ('separatorChar' = '\;' , 'quoteChar' = '\"' ) location 'S3
path/HDFS path for the file';

Related

How to insert text starting with double quotes in a column delimited with | in a import command in db2

Table contains 3 columns
ID -integer
Name-varchar
Description-varchar
A file with .FILE extension has data with delimiter as |
Eg: 12|Ramu|"Ramu" is an architect
Command I am using to load data to db2:
db2 "Load CLIENT FROM ABC.FILE of DEL MODIFIED BY coldel0x7x keepblanks REPLACE INTO tablename(ID,Name,Description) nonrecoverable"
Data is loaded as follows:
12 Ramu Ramu
but I want it as:
12 Ramu "Ramu" is an architect
Take a look at how the format of delimited ASCII files is defined. The double quote (") is an optional delimited for character data. You would need to escape it. I have not tested it, but I would assume that you double the quote as you would do in SQL:
|12|Ramu|"""Ramu"" is an architect"
Delimited files (CSV) are defined in RFC 4180. You need to either use quotes for the entire field or none at all. Only in fields beginning and ending with a quote, other quotes can be used. They need to be escaped as shown.
Use the nochardel modifier.
If you use '|' as a column delimiter, you must use 0x7C and not 0x7x:
MODIFIED BY coldel0x7C keepblanks nochardel

How to use current timestamp as filename for Hive output

I'm using this code to write the results of a Hive query to the specified file:
INSERT OVERWRITE DIRECTORY '/user/test.user/test.csv'
ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t' ESCAPED BY '"' STORED AS TEXTFILE
SELECT
...
I don't want the filename to be test.csv however but the unix timestamp, that is 1517213651.csv or something like that.
I understand I can't use the concat function to manipulate the filename, but that is as far as I got.
How do I get the timestamp of the moment of query execution to be the filename of my output?
EDIT: We're using Cloudera.
Another option is to put the Hive insert inside of a Shell Script. Define a Date variable in the script and then use the Date Variable to define the output file.
TIMESTAMP_VAR=date +"%Y-%m-%d-%H-%M-%S"
FILENAME_VAR=/user/test/${TIMESTAMP_VAR}.csv
You can manipulate the timestamp layout in numerous ways.
you have to add TalendDate.getDate("CCYYMMDD") in file path.
"/File1/Output_File_" + TalendDate.getDate("CCYYMMDD") + ".csv"

Apache Pig store delimiters

I'm using Pig Latin to store values from an alias into the HDFS. The alias contains a semicolon in one of its fields.
dump A;
(Richard & John, 1993)
(Albert, 1994)
A table that shows the data in the HDFS, but the semicolon makes John go to the next column.
| Name | Year |
|--------------|------|
| Richard &amp | John |
| Albert | 1994 |
Trying to use store like this is also not working as expected:
STORE A INTO '/user/hive/warehouse/test.db/names' using PigStorage('\t');
but even when telling PigStore to use tab as delimiter the semicolon breaks the table data. How can I fix it?
I just locally create a file suppose a.txt and copy your data into this file.
(Richard & John, 1993)
(Albert, 1994)
Now I see that your data is not in tab delimiter form and that's why it split after semicolon part.So to solve this problem i just right a query like this
data = load '/home/hduser/Desktop/a.txt' using PigStorage(',');
dump data;
and my output result is this
((Richard & John, 1993))
((Albert, 1994))
I split it using this
,
because your data looks like this delimiter.
Note: I run it my local file system.So to run it locally you must start your pig using this command pig -x local and give your relevant path.
It seems there was a bug in the create table.
create table test.names
(
name varchar(40),
year varchar(40)
)
row format delimited fields terminated by '\073'
lines terminated by '\n';
The delimiter I used was \073 (semicolon), so changing the PigStorage delimiter had no effect.
I'm using \072 (double colon) and it is now working. I think any other delimiter would work as long as it is not a common or possible character in the input data.

Remove spaces and UTF while writing hive table into HDFS files

I am trying to write the hive table into hdfs file using following queries
insert overwrite directory '<HDFS Location>' select customerid,'\t' ,f1,',', f2,',', f3,',', f4,',', f5 from sd_cust_product_recomm_all_emailid_model2 WHERE EMAILID IS NOT NULL;
I am getting the UTF and spaces in the file . The output is somthing like this :
customer1\t^Af1^A,^Af2^A,^Af3^A,^Af4^A,^Af5^A,
I desired output in following format
customer1/tf1,f2,f3,f4,f5
customer2/tf1,f2,f3,f4,f5
with no spaces and UTF
Thanks for the help
The default delimiter is the issue. Data written to the filesystem is serialized as text with columns separated by ^A.
By explicitly mentioning the Field delimiter(Comma) and Row delimiter(\n) you can overcome the issue.
insert overwrite directory '[HDFS Location]' ROW FORMAT DELIMITED
FIELDS TERMINATED BY ',' LINES TERMINATED BY '\n' select
customerid,'\t',f1,f2,f3,f4,f5 from
sd_cust_product_recomm_all_emailid_model2 WHERE EMAILID IS NOT NULL;

How to handle a delimiter in Hive

How do we handle a data in Hive when the \t is in the value and the delimiter is also \t. Suppose for example there is a column as Street, data type as String and value as XXX\tYYY and while creating a table we have used the field delimiter as \t. How will the delimiter work? In this case will the \t in the value will also be delimited?
If your columns with \t values are enclosed by quote character like " the you could use csv-serde to parse the data like this:
Here is a sample dataset that I have loaded:
R1Col1 R1Col2 "R1Col3 MoreData" R1Col4
R2Col2 R2Col2 "R2Col3 MoreData" R2Col4
Register the jar from hive console
hive> add jar /path/to/csv-serde-1.1.2-0.11.0-all.jar;
Create a table with the specified serde and custom properties
hive> create table test_table(c1 string, c2 string, c3 string, c4 string)
> row format serde 'com.bizo.hive.serde.csv.CSVSerde'
> with serdeproperties(
> "separatorChar" = "\t",
> "quoteChar" = "\"",
> "escapeChar" = "\\"
> )
> stored as textfile;
Load your dataset into the table:
hive> load data inpath '/path/to/file/in/hdfs' into table test_table;
Do a select * from test_table to check the results
You could download the csv-serde from here.
It will treat it as a delimiter, yes, same as if you had a semicolon ; in the value and told it to split on semicolon - when the text is scanned, it will see the character and interpret it as the edge of the field.
To get around this, I used sed to find-and-replace characters before loading it into Hive, or I created the Hive table with different delimiters, or left it at the default ^A, or \001, and then, when I extracted it, used sed on the output to replace the \001 with commas or tabs or whatever I needed. Running sed -i 's/oldval/newval/g' file on the command line will replace the characters in your file in place.
Is there a reason you chose to make the table with \t as the delimiter, instead of the default Hive field delimiter of ^A? Since tab is a fairly common character in text, and Hadoop/Hive is used a lot for handling text, it is tough to find a good character for delimiting.
We have faced the same in our data load into hadoop clusters. What we did, added \\t whenever we saw the delimiter is included within a data fields and added the below in the table definition.
Row format delimited fields terminated by \t escaped by \\ lines terminated by \n

Resources