I am able to query over HBase using Drill & convert data into the text from bytes.
Sample data in HBase table "table1":
row1 column=cf:a, timestamp=1447829041294, value=value1
Query I tried:
SELECT CONVERT_FROM(t.row_key, 'UTF8') AS id, CONVERT_FROM(t.`cf`.`a`, 'UTF8') AS col1 from hbase.`table1` t;
Using CONVERT_FROM for every field is not that good.
Is there any other way for this so that I don't need to use this function for every field?
Related
I'm inserting into a Postgres table with a JSON document and I want to generate a unique ID for the document. I can do that on my own, of course, but I was wondering if there was a way to have PG do it.
INSERT INTO test3 (data) VALUES ('{"key": "value", "unique": ????}')
The docs seem to indicate that JSON records fit into various SQL data types, but I don't see how that actually works.
How about just concatenating? Assuming your column is of type json/jsonb, something like the following should work:
INSERT INTO test3 (data) VALUES (('{"key": "value", "unique": "' || uuid_generate_v4() || '"}')::jsonb)
If you're looking to generate a UUID and store it at the same time as a value within a JSON data field, here is something some may find to be a little more sane:
WITH
-- Create a temporary view named "new_entry" containing your data
new_entry
-- This is how you name the view's columns
("key", "unique")
AS (
VALUES
-- This is the actual row returned by the view
(
'value',
uuid_generate_v4()
)
)
INSERT INTO
test3(
data
)
SELECT
-- Convert row to JSON. Column name = key, column value = value.
ROW_TO_JSON(new_entry.*)
FROM
new_entry
First, we're creating a temporary view named new_entry, which containing all of the data want to store in a JSON data field.
Second, we're grabbing that entry and passing it to the ROW_TO_JSON function which converts it to a valid JSON data type. Once converted, it's then inserting the row into the test3 table.
My reasoning for the "sanity" is that more than likely, your JSON object will end up containing more than just two key/value pairs... Rather, you'll end up with a hand full of keys and values, in which it'll be up to you to ensure you don't miss any quotes and escape user input appropriately. Why glue all of this together manually when you can have Postgres do it for you (with the help of ROW_TO_JSON()) while at the same time, making it easier to read and debug?
I have a bunch of MySQL which I need to manually convert to HIVE tables.
Most of the MySQL column types, such as bigint(#), INT(#), varchar(#), ... Have straight forward conversiona.
However, I have a table with column:
' columnName SET( 'v1', 'v2', ... , 'vn')'
I'm not sure how to convert this column. I did some reading and it doesn't look like HIVE supports sets. Should I just name the hive type type('v#')?
Below are Complex Datatype supported by Hive:
arrays
maps
structs
union
You can create struct depending upon your datatype need.
Hey im creating an Hive external table over my flat file data.
The data in my flat file is something like this :
'abc',3,'xyz'
When I load it into the Hive table it shows me the result with the single quotes.
But I want it to be something like this :
abc,3,xyz
Is there any way to do this?
I can think of two ways to get desired result.
Use existing String functions available in hive - SUBSTR and LENGTH.
select SUBSTR("\'abc\'",2,length("\'abc\'")-2) , SUBSTR("\'3\'",2,length("\'3\'")-2) , SUBSTR("\'xyz\'",2,length("\'xyz\'")-2)
Generalized query
select SUBSTR(col1,2,length(col1)-2) , SUBSTR(col2,2,length(col2)-2) , SUBSTR(col3,2,length(col3)-2)
NOTE: Hive SUBSTR method expect string index to start from "1" not "0"
Write your own UDF to chop first and last letter of every string.
How to convert million rows?
Lets assume you have a table (named "staging") with 3 columns and 1million record.
if you run below query, you will have new table "final" which will not have any single quotes at the start or end.
INSERT INTO final SELECT SUBSTR(col1,2,length(col1)-2) , SUBSTR(col2,2,length(col2)-2) , SUBSTR(col3,2,length(col3)-2) from staging
Once the above query finish job , you will have your desired result in "final" table
how to return value of a row if data found(fingerprint template verify)
I'm making a time attendance monitoring system. NOW I can save data to MYSQL and verify it from mysql, but I don't know how to retrieve it from mysql,
I want to return the value of a row where the FPT is verified. I'm using VB.net.
i do not have any idea for that.
any help will be awesome.
First you will have to convert the Fpt into blob file and then access that blob file to select the row that you intend to do..
select row_id from table_name where field_name like %blob_string%
Working with a MS Access database, using one particular table, and scattered throughout the table at varying positions in date columns (which themselves can be in varying orders as a result of the data import) is the text "Not known". I want to replace occurrences of that text string across the whole data table.
The only way I can think of doing it is export to a csv format, and do a REReplace then import the data again, but I would like to know if there is a 'slicker' way?
The columns contain data which is a data import from a csv file so all the columns are text, they can contain a mix of "date string", text, numbers (as string) and null.
You can use replace, it follows basic TSQL implementation :
http://msdn.microsoft.com/en-us/library/ms186862.aspx
Here is an example I did updating the customers table of the Northwind sample database:
update customers set Customers.[Job Title] = replace( Customers.[Job Title], 'Purchasing', 'Manufacturing');
So to distill it into a generic example :
update TABLENAME set FIELD =
replace( FIELD, 'STRING_TO_REPLACE', 'STRING_TO_REPLACE_WITH' )
That updates the entire table in one statement. Be careful ;)
You can do this using Access, running edit-replace command. If you need to do this in code - you can open recordset, loop through records and for each field run:
rst.fields(i)=replace(rst.fields(i),"Not known","Something")
this is how it works in VBA, beleive you can do something similar in coldfusion
Why not just open the CSV file in Notepad++ (or similar) and do a Find/Replace?