I have a oracle table where I have columns like Document (type BLOB), Extension ( VARCHAR2(10) with values like .pdf, .doc) and Document Description(VARCHAR2
(100)). I want to export this data and provide to my customer.
Can this be done in kettle ?
Thanks
I have a MSSQL database that stores images in a BLOB column, and found a way to export these to disk using a dynamic SQL step.
First, select only the columns necessary to build a file name and SQL statement (id, username, record date, etc.). Then, I use a Modified Javascript Value step to create both the output filename (minus the file extension):
outputPath = '/var/output/';
var filename = outputPath + username + '_' + record_date;
// --> '/var/output/joe_20181121'
and the dynamic SQL statement:
var blob_query = "SELECT blob_column FROM dbo.table WHERE id = '" + id + "'";
Then, after using a select to reduce the field count to just the filename and blob_query, I use a Dynamic SQL row step (with "Outer Join" selected) to retrieve the blob from the database.
The last step is to output to a file using Text file output step. It allows you to supply a file name from a field and give it a file extension to append. On the Content tab, all boxes are unchecked, the Format is "no new-line term" and the Compression is "None". The only field exported is the "blob_column" returned from the dynamic SQL step, and the type should be "binary".
Obviously, this is MUCH slower than other table/SQL operations due to the dynamic SQL step making individual database connections for each row... but it works.
Good luck!
Related
Below is how the data looks
Flight Number: SSSVAD123X Date: 2/8/2020 1:04:40 PM Page[s] Printed: 1 Document Name: DownloadAttachment Print Driver: printermodel (printer driver)
I need help creating an Athena SQL create table with in below format
Flight Number Date Pages Printed Document Name Print Driver
SSSVAD123X 2/8/2020 1:04:40 PM 1 DownloadAttachment printermodel
this is new to me, any direction towards solution will work
You may be able to use a regex serde to parse your files. It depends on the shape of your data. You only provide a single line so this assumes that every line in your data files look the same.
Here's the Athena documentation for the feature: https://docs.aws.amazon.com/athena/latest/ug/apache.html
You should be able to do something like the following:
CREATE EXTERNAL TABLE flights (
flight_number STRING,
`date` STRING,
pages_printed INT,
document_name STRING,
print_driver STRING
)
ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.RegexSerDe'
WITH SERDEPROPERTIES (
"input.regex" = "^Flight Number:\\s+(\\S+)\\s+Date:\\s+(\\S+)\\s+Page\\[s\\] Printed:\\s+(\\S+)\\s+Document Name:\\s+(\\S+)\\s+Print Driver:\\s+(\\S+)\\s+\\(printer driver\\)$"
) LOCATION 's3://example-bucket/some/prefix/'
Each capture group in the regex will map to a column, in order.
Since I don't have access to your data I can't test the regex, unfortunately, so there may be errors in it. Hopefully this example is enough to get you started.
First, make sure your data format uses tab spacing between columns because your sample doesn't seem to have a consistent separator.
Flight Number Date Pages Printed Document Name Print Driver
SSSVAD123X 2/8/2020 1:04:40 PM 1 DownloadAttachment printermodel
As per AWS documentation, use the LazySimpleSerDe for CSV, TSV, and Custom-Delimited Files if your data does not include values enclosed in quotes. You don't need to make it complicated using Regex.
Reference: https://docs.aws.amazon.com/athena/latest/ug/supported-serdes.html
As LazySimpleSerDe is the default used by AWS Athena, you don't even need to declare it, see the create table statement for your data sample:
CREATE EXTERNAL TABLE IF NOT EXISTS `mydb`.`mytable` (
`Flight Number` STRING,
`Date` STRING,
`Pages Printed` INT,
`Document Name` STRING,
`Print Driver` STRING)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY '\t'
ESCAPED BY '\\'
LINES TERMINATED BY '\n'
LOCATION
's3://awsexamplebucket1-logs/AWSLogs/'
You can use an online generator to help you in the future: https://www.hivetablegenerator.com/
From the generator page: "Easily convert any JSON (even complex Nested ones), CSV, TSV, or Log sample file to an Apache HiveQL DDL create table statement."
Below is the select query I am trying:
SELECT * from test WHERE doc = '/folder1/folder2-path/testfile.txt';
This query returns zero results.
If I change the query using like, it works omitting the special chars /-.
SELECT * from test WHERE doc LIKE '%folder1%folder2%path%testfile%txt';
This works
How can I fix this query to use eq or IN operator, as I am interested to run a batch select?
To test your situation, I created a text file containing:
hello
there
/folder1/folder2-path/testfile.txt
this/that
here.there
I uploaded the file to a directory on S3, then created an external table in Athena:
CREATE EXTERNAL TABLE stack (doc string)
ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.OpenCSVSerde'
WITH SERDEPROPERTIES ("separatorChar" = ",", "escapeChar" = "\\")
LOCATION 's3://my-bucket/my-folder/'
I then ran the command:
select * from stack WHERE doc = '/folder1/folder2-path/testfile.txt'
It returned:
1 /folder1/folder2-path/testfile.txt
So, it worked for me. Therefore, your problem would either be a result of the contents of the file, or the way that the external table is defined (eg using a different Serde).
I have a custom log format where the log entries vary by the request type. So certain rows have more fields.
Can we specify certain fields as optional so that in rows that they are missing, the values will be set to certain default (null, 0)?
Here are some hypothetical log entries:
{"data":"[2017-09-10 10:44:54.448998 -0000] info ip=773.555.557.445 cluster=\"production\" query=uris type=TXT class=IN rcode=NXDOMAIN cnt=0 offset=74","header":{"recvtime":"2017-09-10 10:45:02","server":"m0107481","refid":"ABC-123"}}
{"data":"[2017-09-10 10:44:54.457718 -0000] info ip=991.509.704.832 cluster=\"inbound\" query=dnsbl type=A class=IN rcode=NOERROR cnt=1 offset=90 score=400","header":{"recvtime":"2017-09-10 10:45:02","server":"m010748","refid":"ABC-123"}}
{"data":"[2017-09-10 10:44:54.457718 -0000] info ip=971.509.704.832 cluster=\"inbound\" query=dnsbl type=A class=IN rcode=REFUSED cnt=1","header":{"recvtime":"2017-09-10 10:45:02","server":"m010574","refid":"ABC-123"}}
Note that each row of the log data is in json format, and the header part is fixed. If query in data is dnsbl, then sometimes the row has a score field, but other times it is missing. And I am planning to use Athena to parse this type of data from S3 and query for some stats in the line of: what % of data are dns queries and what % have score above 300.
It looks like your data is JSON with embedded structured logging in the data field. As long as the data is well formed JSON with one object per line you should be able to create a JSON table and then use functions to extract the other pieces out of the data field. You can create a view that does the extraction so that you don't have to do that in every query.
I'm thinking something like this:
CREATE EXTERNAL TABLE raw_log_entries (
data string,
header struct<recvtime: string, server: string, refid: string>
)
ROW FORMAT SERDE 'org.apache.hive.hcatalog.data.JsonSerDe'
LOCATION 's3://some-bucket/and/path/';
CREATE VIEW log_entries AS
SELECT
header.recvtime,
header.server,
header.refid,
regexp_extract(data, 'query=(\S+)', 1) AS query,
regexp_extract(data, 'type=(\S+)', 1) AS type,
regexp_extract(data, 'score=(\S+)', 1) AS score,
-- and so on
FROM raw_log_entries
You'll have to experiment with the regexes, since I don't have your data I can't be sure if they will work for all cases, but I hope you get the idea.
I've a table "City" with more than 100k records.
The field "name" contains strings like "Roma", "La Valletta".
I receive a file with the city name, all in upper case as in "ROMA".
I need to get the id of the record that contains "Roma" when I search for "ROMA".
In SQL, I must do something like:
select id from city where upper(name) = upper(%name%)
How can I do this in kettle?
Note: if the city is not found, I use an Insert/update field to create it, so I must avoid duplicates generated by case-sensitive names.
You can make use of the String Operations steps in Pentaho Kettle. Set the Lower/Upper option to Y
Pass the city (name) from the City table to the String operations steps which will do the Upper case of your data stream i.e. city name. Join/lookup with the received file and get the required id.
More on String Operations step in pentaho wiki.
You can use a 'Database join' step. Here you can write the sql:
select id from city where upper(name) = upper(?)
and specify the city field name from the text file as parameter. With 'Number of rows to return' and 'Outer join?' you can control the join behaviour.
This solution doesn't work well with a large number of rows, as it will execute one query per row. In those cases Rishu's solution is better.
This is how I did:
First "Modified JavaScript value" step for create a query:
var queryDest="select coalesce( (select id as idcity from city where upper(name) = upper('"+replace(mycity,"'","\'\'")+"') and upper(cap) = upper('"+mycap+"') ), 0) as idcitydest";
Then I use this string as a query in a Dynamic SQL row.
After that,
IF idcitydest == 0 then
insert new city;
else
use the found record
This system make a query for file's row but it use few memory cache
I am writing a unit test for appending data to CSV file on a datalake. I want to test it by finding my test data appended to the same file and once I found it I want to delete the row I inserted. Basically once I found the test data My test will pass but as the tests are run in production so I have to search for my test data i.e to find the row I have inserted in a file and delete it after the test is run.
I want to do it without using usql inorder to avoid the cost factor involved in using usql. What are the other possible ways we can do it?
You cannot delete a row (or any part) from a file. Azure data lake store is an append-only file system. Data once committed cannot be erased or updated. If you're testing in production, your application needs to be aware of test rows and ignore them appropriately.
The other choice is to read all the rows in U-SQL and then write an output excluding the test rows.
Like other big data analytics platforms, ADLA / U-SQL does not support appending to files per se. What you can do is take an input file, append some content to it (eg via U-SQL) and write it out as another file, eg a simple example:
DECLARE #inputFilepath string = "input/input79.txt";
DECLARE #outputFilepath string = "output/output.txt";
#input =
EXTRACT col1 int,
col2 DateTime,
col3 string
FROM #inputFilepath
USING Extractors.Csv(skipFirstNRows : 1);
#output =
SELECT *
FROM #input
UNION ALL
SELECT *
FROM(
VALUES
(
2,
DateTime.Now,
"some string"
) ) AS x (col1, col2, col3);
OUTPUT #output
TO #outputFilepath
USING Outputters.Csv(quoting : false, outputHeader : true);
If you want further control, you can do some things via the Powershell SDK, eg test an item exists:
Test-AdlStoreItem -Account $adls -Path "/data.csv"
or move an item with Move-AzureRmDataLakeStoreItem. More details here:
Manage Azure Data Lake Analytics using Azure PowerShell