RegEx in the select for DB2 - regex

I have a table with one column having a large json object in the format below. The column datatype is VARCHAR
column1
--------
{"key":"value",....}
I'm interested in the first value of the column data
in regex I can do it by .*?:(.*),.* with group(1) giving me the value
How can i use it in the select query

Don't do that, it's bad database design. Shred the keys and values to their own table as columns, or use the XML data type. XML would work fine because you can index the structure well, and you can use XPATH queries on the data. XPATH supports regexp natively.

You can use regular expression with xQuery, you just need to call the function matches from a SQL query or a FLORW query.
This is an example of how to use regular expressions from SQL:
db2 "with val as (
select t.text
from texts t
where xmlcast(xmlquery('fn:matches(\$TEXT,''^[A-Za-z 0-9]*$'')') as integer) = 0
)
select * from val"
For more information:
http://pic.dhe.ibm.com/infocenter/db2luw/v10r5/topic/com.ibm.db2.luw.xml.doc/doc/xqrfnmat.html
http://angocadb2.blogspot.fr/2014/04/regular-expressions-in-db2.html

DB2 doesn't have any built in regex functionality, unfortunately. I did find an article about how to add this with libraries:
http://www.ibm.com/developerworks/data/library/techarticle/0301stolze/0301stolze.html
Without regexes, this operation would be a mess. You could make a function that goes through the string character by character to find the first value. Or, if you will need to do more than this one operation, you could make a procedure that parses the json and throws it into a table of keys/values. Neither one sounds fun, though.

In DB2 for z/OS you will have to pass the variable to XMLQUERY with the PASSING option
db2 "with val as (
select t.text
from texts t
where xmlcast(xmlquery('fn:matches($TEXT,''^[A-Za-z 0-9]*$'')'
PASSING t.text as "TEXT") as integer) = 0
)
select * from val"

Related

REGEXP_EXTRACT in Google BigQuery returns no results

I am using REGEXP_EXTRACT function in Google BigQuery to extract a specific word from a string. While regexp works good when tested, function REGEXP_EXTRACT returns null in Google BigQuery.
For example, there is string "RR_SM_Brand_A_Additive_Clean_jun2020", and I want to extract a value from the list (Brand_A, Brand_B, Brand_C, etc.)
When I test RegExp, I receive correct value Brand_A: https://regexr.com/5tecm
RegExp Code: Brand_A|Brand_B (thanks to #Barmar)
But when I run it in Google BigQuery:
SELECT distinct utm_campaign, -- REGEXP_EXTRACT(utm_campaign, r"(?:Brand_A|Brand_B)") REGEXP_EXTRACT(utm_campaign, r"Brand_A|Brand_B") FROM project.dataset.table WHERE utm_campaign = "RB_Display_Brand_A_Botanica_2020"
I receive "This query returned no results.", and not expected Brand_A value.
Note: BigQuery does not return "Cannot parse regular expression: invalid perl operator: (?<"." like in question "duplicate"
I'd suggest that your WHERE clause may be at issue. Both forms you use extract the brand string you appear to be asking for. If the REGEXP_EXTRACT was not matching you'd still get rows, but the value would be NULL.
Converting this to just use the literal from your existing where clause:
SELECT
val,
REGEXP_EXTRACT(val, r"(?:Brand_A|Brand_B)"),
REGEXP_EXTRACT(val, r"Brand_A|Brand_B")
FROM
(
SELECT "RB_Display_Brand_A_Botanica_2020" as val
)

How to precompile regular expressions?

The PostgreSQL's regular expressions are expressed as strings (text datatype),
SELECT regexp_matches('foobarbequebaz', '(bar)(beque)'::text);
so is natural to imagine it as a dynamic parameter... But no, is not possible to be dynamic... This query "failed to find conversion function from unknown to text",
SELECT regexp_matches('foobarbequebaz', (SELECT '(bar)(beque)') );
... So, we can imagine something intermediary to reuse regular expressions, as pre-compile it. It is possible with PostgreSQL v10?
The error message has nothing to do with "dynamic" values or "precompiled" values. It simply tells you that the result of (SELECT '(bar)(beque)') has an unknown data type, but regexp_matches() expects text
So you need to cast that result to text:
SELECT regexp_matches('foobarbequebaz', (SELECT '(bar)(beque)')::text );
If you want to pass the expressions from somewhere else, you can do it like this:
with list_of_expressions (expression) as (
values
('(bar)(beque)'),
('(foo)')
)
SELECT regexp_matches('foobarbequebaz', expression)
from list_of_expressions;
Of course list_of_expressions could also be a table in your database.

How to Extract Numeric Range from Text in SQL

I am fairly new to SQL and I'm trying to extract some data from an ORACLE DB. My goal is to return rows where the query value lies in the range speicified by the "AA_SYNTAX" column in a table.
For example:
If the "AA_SYNTAX" column is 'p.G12_V14insR' and my search value is 13, I want to return that row. This column is organized as p.%number_%number%. So basically I want to return the two numerical values from this column and see if my query value is between them.
I have all the tables I need joined together and everything, just not sure how to construct a query like this. I know in regex I would do something like "\d+" but im not sure how to translate this into SQL.
Thanks
Using Oracle, you can use Regular Expressions to extract a number from the string.
More specifically, I would look into REGEXP_SUBSTR.
Using the date given in your example above, you could use:
with cte as
(
select 'p.G12_V14insR' as AA_SYNTAX from dual
)
select
REGEXP_SUBSTR(AA_SYNTAX,'p\.[[:alpha:]]+([[:digit:]]+)', 1, 1, NULL, 1) as Bottom
,REGEXP_SUBSTR(AA_SYNTAX,'\_[[:alpha:]]+([[:digit:]]+)', 1, 1, NULL, 1) as Top
from cte
I'm sure you could clean up the Regular Expression quite a bit, but, given this, you get the value of 14 for Top and 12 for Bottom.
Hope this helps move you in the right direction.

Matching number sequences in SQLite with random character separators

I have an sqlite database which has number sequences with random separators. For example
_id data
0 123-45/678>90
1 11*11-22-333
2 4-4-5-67891
I want to be able to query the database "intelligently" with and without the separators. For example, both these queries returning _id=0
SELECT _id FROM myTable WHERE data LIKE '%123-45%'
SELECT _id FROM myTable WHERE data LIKE '%12345%'
The 1st query works as is, but the 2nd query is the problem. Because the separators appear randomly in the database there are too many combinations to loop through in the search term.
I could create two columns, one with separators and one without, running each query against each column, but the database is huge so I want to avoid this if possible.
Is there some way to structure the 2nd query to achieve this as is ? Something like a regex on each row during the query ? Pseudo code
SELECT _id
FROM myTable
WHERE REPLACEALL(data,'(?<=\\d)[-/>*](?=\\d)','') LIKE '%12345%'
Ok this is far from being nice, but you could straightforwardly nest the REPLACE function. Example:
SELECT _id FROM myTable
WHERE REPLACE(..... REPLACE(REPLACE(data,'-',''),'_',''), .... '<all other separators>','') = '12345'
When using this in practice (--not that I would recommend it, but at least its simple), you surely might wrap it inside a function.
EDIT: for a small doc on the REPLACE function, see here, for example.
If I get it right, is this what you want?
SELECT _id
FROM myTable
WHERE Replace(Replace(Replace(data, '?', ''), '/', ''), '-', '') LIKE '%12345%'

Bulk inserts with Sitecore Rocks

Is it possible to do a bulk insert with Sitecore Rocks? Something along the lines of SQL's
INSERT INTO TABLE1 SELECT COL1, COL2 FROM TABLE2
If so, what is the syntax? I'd like to add an item under any other item of a given template type.
I've tried using this syntax:
insert into (
##itemname,
##templateitem,
##path,
[etc.]
)
select
'Bulk-Add-Item',
//*[##id='{B2477E15-F54E-4DA1-B09D-825FF4D13F1D}'],
Path + '/Item',
[etc.]
To this, Query Analyzer responds:
"values" expected at position 440.
Please note that I have not found a working concatenation operator. For example,
Select ##item + '/value' from //sitecore/content/home/*
just returns '/value'. I've also tried ||, &&, and CONCATENATE without success.
There is apparently a way of doing bulk updates with CSV, but doing bulk updates directly from Sitecore Query Analyzer would be very useful
Currently you cannot do bulk inserts, but it is a really nice idea. I'll see what I can do.
Regarding the concatenation operator, this following works in the Query Analyzer:
select #Text + "/Value" from /sitecore/content/Home
This returns "Welcome to Sitecore/Value".
The ##item just returns empty, because it is not a valid system attribute.