I have some sample data in Hive as
select "abc:def:ghi:jkl" as data
union all
select "jkl:mno:23ar:stu:abc:def:ghi:7345" as data
I want to extract the strings until 3rd colon so that I get the output as
abc:def:ghi
jkl:mno:23ar
I want to keep N as variable so that I can shrink the output text as needed. How do I do this in Hive?
SELECT regexp_replace(`data`, '^([^:]+:[^:]+:[^:]+).*$', "$1")
FROM
( SELECT "abc:def:ghi:jkl" AS `data`
UNION ALL SELECT "jkl:mno:23ar:stu:abc:def:ghi:7345" AS `data`) AS tmp
With using split and posexplode functions, you can combine again with filtering position
select t.dataId, concat_ws(":", collect_list(t.cell)) as firstN from (
SELECT x.dataId, pos as pos, cell
FROM (
select 1 as dataId, "jkl:mno:23ar:stu:abc:def:ghi:7345" as data
union all
select 2 as dataId, "abc:def:ghi:7345" as data
) x
LATERAL VIEW posexplode(split(x.data,':')) dataTable AS pos, cell
) t
where t.pos<3
group by t.dataId
With variable:
set hivevar:n=3; --variable, you can pass it to the script
with your_table as(
select stack(2,"abc:def:ghi:jkl", "jkl:mno:23ar:stu:abc:def:ghi:7345")as data
)
select regexp_replace(regexp_extract(data,'([^:]*:){1,${hivevar:n}}',0),':$','') from your_table;
Result:
OK
abc:def:ghi
jkl:mno:23ar
Time taken: 0.105 seconds, Fetched: 2 row(s)
Quantifier {1,${hivevar:n}} after variable substitution will become {1,3} which means 1 to 3 times, this allows to extract values shorter than 3. If you need not to extract shorter values, use {${hivevar:n}} quantifier. If there are < than N elements, it will extract empty string in this case.
Select substring_index('abc:def:ghi:jkl',':',3) as data
Union all
Select substring_index('jkl:mno:23ar:stu:abc:def:ghi:7345',':',3) as data;
Related
Would it be possible to construct SQL to concatenate column values from
multiple rows?
The following is an example:
Table A
PID
A
B
C
Table B
PID SEQ Desc
A 1 Have
A 2 a nice
A 3 day.
B 1 Nice Work.
C 1 Yes
C 2 we can
C 3 do
C 4 this work!
Output of the SQL should be -
PID Desc
A Have a nice day.
B Nice Work.
C Yes we can do this work!
So basically the Desc column for out put table is a concatenation of the SEQ values from Table B?
Any help with the SQL?
There are a few ways depending on what version you have - see the oracle documentation on string aggregation techniques. A very common one is to use LISTAGG:
SELECT pid, LISTAGG(Desc, ' ') WITHIN GROUP (ORDER BY seq) AS description
FROM B GROUP BY pid;
Then join to A to pick out the pids you want.
Note: Out of the box, LISTAGG only works correctly with VARCHAR2 columns.
There's also an XMLAGG function, which works on versions prior to 11.2. Because WM_CONCAT is undocumented and unsupported by Oracle, it's recommended not to use it in production system.
With XMLAGG you can do the following:
SELECT XMLAGG(XMLELEMENT(E,ename||',')).EXTRACT('//text()') "Result"
FROM employee_names
What this does is
put the values of the ename column (concatenated with a comma) from the employee_names table in an xml element (with tag E)
extract the text of this
aggregate the xml (concatenate it)
call the resulting column "Result"
With SQL model clause:
SQL> select pid
2 , ltrim(sentence) sentence
3 from ( select pid
4 , seq
5 , sentence
6 from b
7 model
8 partition by (pid)
9 dimension by (seq)
10 measures (descr,cast(null as varchar2(100)) as sentence)
11 ( sentence[any] order by seq desc
12 = descr[cv()] || ' ' || sentence[cv()+1]
13 )
14 )
15 where seq = 1
16 /
P SENTENCE
- ---------------------------------------------------------------------------
A Have a nice day
B Nice Work.
C Yes we can do this work!
3 rows selected.
I wrote about this here. And if you follow the link to the OTN-thread you will find some more, including a performance comparison.
The LISTAGG analytic function was introduced in Oracle 11g Release 2, making it very easy to aggregate strings.
If you are using 11g Release 2 you should use this function for string aggregation.
Please refer below url for more information about string concatenation.
http://www.oracle-base.com/articles/misc/StringAggregationTechniques.php
String Concatenation
As most of the answers suggest, LISTAGG is the obvious option. However, one annoying aspect with LISTAGG is that if the total length of concatenated string exceeds 4000 characters( limit for VARCHAR2 in SQL ), the below error is thrown, which is difficult to manage in Oracle versions upto 12.1
ORA-01489: result of string concatenation is too long
A new feature added in 12cR2 is the ON OVERFLOW clause of LISTAGG.
The query including this clause would look like:
SELECT pid, LISTAGG(Desc, ' ' on overflow truncate) WITHIN GROUP (ORDER BY seq) AS desc
FROM B GROUP BY pid;
The above will restrict the output to 4000 characters but will not throw the ORA-01489 error.
These are some of the additional options of ON OVERFLOW clause:
ON OVERFLOW TRUNCATE 'Contd..' : This will display 'Contd..' at
the end of string (Default is ... )
ON OVERFLOW TRUNCATE '' : This will display the 4000 characters
without any terminating string.
ON OVERFLOW TRUNCATE WITH COUNT : This will display the total
number of characters at the end after the terminating characters.
Eg:- '...(5512)'
ON OVERFLOW ERROR : If you expect the LISTAGG to fail with the
ORA-01489 error ( Which is default anyway ).
For those who must solve this problem using Oracle 9i (or earlier), you will probably need to use SYS_CONNECT_BY_PATH, since LISTAGG is not available.
To answer the OP, the following query will display the PID from Table A and concatenate all the DESC columns from Table B:
SELECT pid, SUBSTR (MAX (SYS_CONNECT_BY_PATH (description, ', ')), 3) all_descriptions
FROM (
SELECT ROW_NUMBER () OVER (PARTITION BY pid ORDER BY pid, seq) rnum, pid, description
FROM (
SELECT a.pid, seq, description
FROM table_a a, table_b b
WHERE a.pid = b.pid(+)
)
)
START WITH rnum = 1
CONNECT BY PRIOR rnum = rnum - 1 AND PRIOR pid = pid
GROUP BY pid
ORDER BY pid;
There may also be instances where keys and values are all contained in one table. The following query can be used where there is no Table A, and only Table B exists:
SELECT pid, SUBSTR (MAX (SYS_CONNECT_BY_PATH (description, ', ')), 3) all_descriptions
FROM (
SELECT ROW_NUMBER () OVER (PARTITION BY pid ORDER BY pid, seq) rnum, pid, description
FROM (
SELECT pid, seq, description
FROM table_b
)
)
START WITH rnum = 1
CONNECT BY PRIOR rnum = rnum - 1 AND PRIOR pid = pid
GROUP BY pid
ORDER BY pid;
All values can be reordered as desired. Individual concatenated descriptions can be reordered in the PARTITION BY clause, and the list of PIDs can be reordered in the final ORDER BY clause.
Alternately: there may be times when you want to concatenate all the values from an entire table into one row.
The key idea here is using an artificial value for the group of descriptions to be concatenated.
In the following query, the constant string '1' is used, but any value will work:
SELECT SUBSTR (MAX (SYS_CONNECT_BY_PATH (description, ', ')), 3) all_descriptions
FROM (
SELECT ROW_NUMBER () OVER (PARTITION BY unique_id ORDER BY pid, seq) rnum, description
FROM (
SELECT '1' unique_id, b.pid, b.seq, b.description
FROM table_b b
)
)
START WITH rnum = 1
CONNECT BY PRIOR rnum = rnum - 1;
Individual concatenated descriptions can be reordered in the PARTITION BY clause.
Several other answers on this page have also mentioned this extremely helpful reference:
https://oracle-base.com/articles/misc/string-aggregation-techniques
LISTAGG delivers the best performance if sorting is a must(00:00:05.85)
SELECT pid, LISTAGG(Desc, ' ') WITHIN GROUP (ORDER BY seq) AS description
FROM B GROUP BY pid;
COLLECT delivers the best performance if sorting is not needed(00:00:02.90):
SELECT pid, TO_STRING(CAST(COLLECT(Desc) AS varchar2_ntt)) AS Vals FROM B GROUP BY pid;
COLLECT with ordering is bit slower(00:00:07.08):
SELECT pid, TO_STRING(CAST(COLLECT(Desc ORDER BY Desc) AS varchar2_ntt)) AS Vals FROM B GROUP BY pid;
All other techniques were slower.
Before you run a select query, run this:
SET SERVEROUT ON SIZE 6000
SELECT XMLAGG(XMLELEMENT(E,SUPLR_SUPLR_ID||',')).EXTRACT('//text()') "SUPPLIER"
FROM SUPPLIERS;
Try this code:
SELECT XMLAGG(XMLELEMENT(E,fieldname||',')).EXTRACT('//text()') "FieldNames"
FROM FIELD_MASTER
WHERE FIELD_ID > 10 AND FIELD_AREA != 'NEBRASKA';
In the select where you want your concatenation, call a SQL function.
For example:
select PID, dbo.MyConcat(PID)
from TableA;
Then for the SQL function:
Function MyConcat(#PID varchar(10))
returns varchar(1000)
as
begin
declare #x varchar(1000);
select #x = isnull(#x +',', #x, #x +',') + Desc
from TableB
where PID = #PID;
return #x;
end
The Function Header syntax might be wrong, but the principle does work.
In Azure Synapse, I'd like to convert this table
id,list
0,'a:b'
1,'d:e'
2,'g:h'
into this one
id,col1,col2
0,a,b
1,d,e
2,g,h
I'm sure STRING_SPLIT comes into play, but it's return format confuses me.
If your data is as simple as shown then something like this will work:
;WITH cte AS (
SELECT *, CHARINDEX( ':', list ) AS xpos
FROM dbo.rawData
)
SELECT id, LEFT( list, xpos - 1 ) AS col1, SUBSTRING ( list, xpos + 1, 50 ) AS col2
FROM cte
If your data has the single quotes then use REPLACE function to clean them. If this does not work for you, please provide some more realistic sample data.
I am looking to extract parts of a string that follow specified letters, for example from the below string:
wc:275,nwc:267,c1.3:2,c12.1:25,c12.10:39,c12.12:21,c12.13:4
I am looking to extract 275 (for wc), 2 (for c1.3) and 25 (for c12.1).
I have tried the following but the fields anew, ridanxietycnt and wordcount just show "NULL".
SELECT substr(CAST((DATE) AS STRING),0,8) as daydate,
count(1) as count,
avg(CAST(REGEXP_REPLACE(V2Tone, r',.*', "")AS FLOAT64)) tone,
avg(CAST(REGEXP_EXTRACT(GCAM, r'c1.3:([-d.]+)')AS FLOAT64)) anew,
sum(CAST(REGEXP_EXTRACT(GCAM, r'c12.1:([-d.]+)')AS FLOAT64)) ridanxietycnt,
sum(CAST(REGEXP_EXTRACT(GCAM, r'wc:(d+)')AS FLOAT64)) wordcount
FROM `gdelt-bq.gdeltv2.gkg_partitioned` where _PARTITIONTIME BETWEEN TIMESTAMP('2019-02-02') AND TIMESTAMP('2019-02-02')
group by daydate
I would expect to see the aggregated number for each column.
I wonder if the issue is with the regex expression?
You can treat them as simple key/value pairs and then do the aggregation on top of it. Something like:
select
substr(CAST((DATE) AS STRING),0,8) as daydate,
split(x,':')[safe_offset(0)] as key,
cast(split(x,':')[safe_offset(1)] as float64) as value
from `gdelt-bq.gdeltv2.gkg_partitioned`,
unnest(split(GCAM, ',')) as x
where _PARTITIONTIME BETWEEN TIMESTAMP('2019-02-02') AND TIMESTAMP('2019-02-02')
Hope this helps.
This should get you 2 (anew), 25 (ridanxietycnt), 275 (wordcount), in this order
SELECT
SAFE_CAST(REGEXP_EXTRACT('wc:275,nwc:267,c1.3:2,c12.1:25,c12.10:39,c12.12:21,c12.13:4', r'c1.3:(\d+)') as FLOAT64) anew,
SAFE_CAST(REGEXP_EXTRACT('wc:275,nwc:267,c1.3:2,c12.1:25,c12.10:39,c12.12:21,c12.13:4', r'c12.1:(\d+)') as FLOAT64) ridanxietycnt,
SAFE_CAST(REGEXP_EXTRACT('wc:275,nwc:267,c1.3:2,c12.1:25,c12.10:39,c12.12:21,c12.13:4', r'wc:(\d+)') as FLOAT64) wordcount
I am writing a query where I need to perform a date format transformation to meet the specified requirements.
In the database which I have to search, the date format looks like the one in the example: 5y 6m 10d with spaces in between and with optional digits (10y 30d; 1m 23d; 6m are also valid) and they are always ordered (first years, then month and then days).
The format transformation should be the following:
10y 6m 10d => 100610
1y 10m 1d => 011001
6m 2d => 000602
So that the output is always a 6-digit number.
I tried writing regular expressions within REGEX_SUBSTR to isolate the tokens and then concatenate them together in the type of SELECT REGEXP_SUBSTR(text_source, '(\d+)*y') FROM database and I also tried using the REGEX_REPLACE function. Nevertheless, I am not able to perform the transformation to two digits per token without spaces, nor replace one pattern by another, I can only replace the pattern by another string.
Although I am able to output the token separation without spaces by writing the function above. I am not able to get the whole transformation. Is there any possibility of writing a RegEx and combining it with any of the PL/SQL functions in order to transform the dates stated on the list above ? I am also open to hear any other solutions not involving RegEx, I just thought it was sensible to make a proper use of them here.
Here is a simple solution in SQL.
you get the values for year, month and day e.g. with regexp_substr.
with nvl you set the value to 0 if there it is null.
lpad it with 0
with tab as(
select '10y 6m 10d' as str from dual union all
select '1y 10m 1d ' as str from dual union all
select '6m 2d ' as str from dual
)
select lpad(nvl(y,0), 2,'0') ||lpad(nvl(m,0), 2,'0')|| lpad(nvl(d,0), 2,'0')
from (
select rtrim(regexp_substr(str, '[0-9]{1,2}y', 1),'y') as y
,rtrim(regexp_substr(str, '[0-9]{1,2}m', 1),'m') as m
,rtrim(regexp_substr(str, '[0-9]{1,2}d', 1),'d') as d
from tab
)
;
LPAD(N
------
100610
011001
000602
I hope it works
declare
myDate_ varchar2(50) := REPLACE('1y 10m 81d',' ','');
year_ varchar2(50);
month_ varchar2(50);
day_ varchar2(50);
begin
if instrb(myDate_,'y',1,1)>0 then
year_ := lpad(regexp_substr(substr(myDate_,0,instrb(myDate_,'y',1,1)), '[^y]+',1 , 1),2,0);
end if;
if instrb(myDate_,'m',1,1)>0 then
month_ := lpad(regexp_substr(substr(myDate_,instrb(myDate_,'y',1,1)+1,instrb(myDate_,'m',1,1)), '[^m]+',1 , 1),2,0);
end if;
if instrb(myDate_,'d',1,1)>0 then
day_ := lpad(regexp_substr(substr(myDate_,instrb(myDate_,'m',1,1)+1,instrb(myDate_,'d',1,1)), '[^d]+',1 , 1),2,0);
end if;
dbms_output.put_line(year_||month_||day_);
end;
As updating my previous question,
I've a some newline separated strings.
I need to insert those each words into a table.
The new logic and its condition is that, it should be inserted if not exists, or update the corresponding count by 1. (as like using MERGE).
But my current query is just using insert, so I've used CONNECT BY LEVEL method without checking the value is existing or not.
it syntax is somewhat like:
if the word already EXISTS THEN
UPDATE my_table set w_count = w_count +1 where word = '...';
else
INSERT INTO my_table (word, w_count)
SELECT REGEXP_SUBSTR(i_words, '[^[:cntrl:]]+', 1 ,level),
1
FROM dual
CONNECT BY REGEXP_SUBSTR(i_words, '[^[:cntrl:]]+', 1 ,level) IS NOT NULL;
end if;
Try this
MERGE INTO my_table m
USING(WITH the_data AS (
SELECT 'a
bb
&
c' AS dat
FROM dual
)
SELECT regexp_substr(dat, '[^[:cntrl:]]+', 1 ,LEVEL) wrd
FROM the_data
CONNECT BY regexp_substr(dat, '[^[:cntrl:]]+', 1 ,LEVEL) IS NOT NULL) word_list
ON (word_list.wrd = m.word)
WHEN matched THEN UPDATE SET m.w_count = m.w_count + 1
WHEN NOT matched THEN insert(m.word,m.w_count) VALUES (word_list.wrd,1);
More details on MERGE here.
Sample fiddle