Get Comma Separated Ids in variable plsql [duplicate] - sql

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SQL Query to concatenate column values from multiple rows in Oracle
(10 answers)
Closed 4 years ago.
I have a table like this
id | Name
===========
1 | A
2 | A
3 | A
4 | B
5 | B
6 | C
i am writing select id from tbl where name = "A", i want to get all three ids (1,2,3) like this separated by comma in a single variable and then I want to use that variable in another select query having IN clause, any help please?


As others have pointed out, using listagg() should do the trick:
SELECT listagg(id, ',') WITHIN GROUP (ORDER BY id) as concatenation
FROM mytable
WHERE name = 'A'


this is working:
create table ns_1111(col1 number,col2 varchar(20));
insert into ns_1111 values(1,'A');
insert into ns_1111 values(2,'A');
insert into ns_1111 values(3,'A');
insert into ns_1111 values(4,'B');
insert into ns_1111 values(5,'B');
insert into ns_1111 values(6,'C');
SELECT * FROM ns_1111;
select * from (SELECT LISTAGG(col1, ', ') WITHIN GROUP (ORDER BY col1)
FROM ns_1111 group by col2) where rownum<=1 ;
output:
1, 2, 3

Related

Possible to un-anonymize VALUES clause?

Let's say I have the following as a starting point:
select * from (values (1,'a'),(2,'b'))
Is it possible to provide column names to the value columns up-stream, for example something like:
select
col1 AS id,
col2 AS letter
from (
<anonymous values>
)
Or is it basically once you have an anonymous values clause you cannot name it.

You can use a table alias that also specifies column names:
select *
from (
values (1,'a'),(2,'b')
) as v(id, letter);

use an alias:
select * from (values (1,'a'),(2,'b')) as foo(id,txt);
id | txt
----+-----
1 | a
2 | b
(2 rows)

Absolutely
Just add the column names to the query alias
select q.id, q.col
from (values
(1,'a'),
(2,'b')
) q(id, col)

SQL grouping by distinct values in a multi-value string column

(I want to perform a group-by based on the distinct values in a string column that has multiple values
The said column has a list of strings in a standard format separated by commas. The potential values are only a,b,c,d.
For example the column collection (type: String) contains:
Row 1: ["a","b"]
Row 2: ["b","c"]
Row 3: ["b","c","a"]
Row 4: ["d"]`
The expected output is a count of unique values:
collection | count
a | 2
b | 3
c | 2
d | 1

For all the below i used this table:
create table tmp (
id INT auto_increment,
test VARCHAR(255),
PRIMARY KEY (id)
);
insert into tmp (test) values
("a,b"),
("b,c"),
("b,c,a"),
("d")
;
If the possible values are only a,b,c,d you can try one of this:
Tke note that this will only works if you have not so similar values like test and test_new, because then the test would be joined also with all test_new rows and the count would not match
select collection, COUNT(*) as count from tmp JOIN (
select CONCAT("%", tb.collection, "%") as like_collection, collection from (
select "a" COLLATE utf8_general_ci as collection
union select "b" COLLATE utf8_general_ci as collection
union select "c" COLLATE utf8_general_ci as collection
union select "d" COLLATE utf8_general_ci as collection
) tb
) tb1
ON tmp.test LIKE tb1.like_collection
GROUP BY tb1.collection;
Which will give you the result you want
collection | count
a | 2
b | 3
c | 2
d | 1
or you can try this one
SELECT
(SELECT COUNT(*) FROM tmp WHERE test LIKE '%a%') as a_count,
(SELECT COUNT(*) FROM tmp WHERE test LIKE '%b%') as b_count,
(SELECT COUNT(*) FROM tmp WHERE test LIKE '%c%') as c_count,
(SELECT COUNT(*) FROM tmp WHERE test LIKE '%d%') as d_count
;
The result would be like this
a_count | b_count | c_count | d_count
2 | 3 | 2 | 1

What you need to do is to first explode the collection column into separate rows (like a flatMap operation). In redshift the only way to generate new rows is to JOIN - so let's CROSS JOIN your input table with a static table having consecutive numbers, and take only ones having id less or equal to number of elements in the collection. Then we'll use split_part function to read the item at correct index. Once we have the exploaded table, we'll do a simple GROUP BY.
If your items are stored as JSON array strings ('["a", "b", "c"]') then you can use JSON_ARRAY_LENGTH and JSON_EXTRACT_ARRAY_ELEMENT_TEXT instead of REGEXP_COUNT and SPLIT_PART respectively.
with
index as (
select 1 as i
union all select 2
union all select 3
union all select 4 -- could be substituted with 'select row_number() over () as i from arbitrary_table limit 4'
),
agg as (
select 'a,b' as collection
union all select 'b,c'
union all select 'b,c,a'
union all select 'd'
)
select
split_part(collection, ',', i) as item,
count(*)
from index,agg
where regexp_count(agg.collection, ',') + 1 >= index.i -- only get rows where number of items matches
group by 1

sql query db2 9.7 [duplicate]

Is there a built in function for comma separated column values in DB2 SQL?
Example: If there are columns with an ID and it has 3 rows with the same ID but have three different roles, the data should be concatenated with a comma.
ID | Role
------------
4555 | 2
4555 | 3
4555 | 4
The output should look like the following, per row:
4555 2,3,4

LISTAGG function is new function in DB2 LUW 9.7
see example:
create table myTable (id int, category int);
insert into myTable values (1, 1);
insert into myTable values (2, 2);
insert into myTable values (5, 1);
insert into myTable values (3, 1);
insert into myTable values (4, 2);
example: select without any order in grouped column
select category, LISTAGG(id, ', ') as ids from myTable group by category;
result:
CATEGORY IDS
--------- -----
1 1, 5, 3
2 2, 4
example: select with order by clause in grouped column
select
category,
LISTAGG(id, ', ') WITHIN GROUP(ORDER BY id ASC) as ids
from myTable
group by category;
result:
CATEGORY IDS
--------- -----
1 1, 3, 5
2 2, 4

I think with this smaller query, you can do what you want.
This is equivalent of MySQL's GROUP_CONCAT in DB2.
SELECT
NUM,
SUBSTR(xmlserialize(xmlagg(xmltext(CONCAT( ', ',ROLES))) as VARCHAR(1024)), 3) as ROLES
FROM mytable
GROUP BY NUM;
This will output something like:
NUM ROLES
---- -------------
1 111, 333, 555
2 222, 444
assumming your original result was something like that:
NUM ROLES
---- ---------
1 111
2 222
1 333
2 444
1 555

Depending of the DB2 version you have, you can use XML functions to achieve this.
Example table with some data
create table myTable (id int, category int);
insert into myTable values (1, 1);
insert into myTable values (2, 2);
insert into myTable values (3, 1);
insert into myTable values (4, 2);
insert into myTable values (5, 1);
Aggregate results using xml functions
select category,
xmlserialize(XMLAGG(XMLELEMENT(NAME "x", id) ) as varchar(1000)) as ids
from myTable
group by category;
results:
CATEGORY IDS
-------- ------------------------
1 <x>1</x><x>3</x><x>5</x>
2 <x>2</x><x>4</x>
Use replace to make the result look better
select category,
replace(
replace(
replace(
xmlserialize(XMLAGG(XMLELEMENT(NAME "x", id) ) as varchar(1000))
, '</x><x>', ',')
, '<x>', '')
, '</x>', '') as ids
from myTable
group by category;
Cleaned result
CATEGORY IDS
-------- -----
1 1,3,5
2 2,4
Just saw a better solution using XMLTEXT instead of XMLELEMENT here.

Since DB2 9.7.5 there is a function for that:
LISTAGG(colname, separator)
check this for more information: Using LISTAGG to Turn Rows of Data into a Comma Separated List

My problem was to transpose row fields(CLOB) to column(VARCHAR) with a CSV and use the transposed table for reporting. Because transposing on report layer slows down the report.
One way to go is to use recursive SQL. You can find many articles about that but its difficult and resource consuming if you want to join all your recursive transposed columns.
I created multiple global temp tables where I stored single transposed columns with one key identifier. Eventually, I had 6 temp tables for joining 6 columns but due to limited resource allocation I wasnt able to bring all columns together. I opted to below 3 formulas and then I just had to run 1 query which gave me output in 10 seconds.
I found various articles on using XML2CLOB functions and have found 3 different ways.
REPLACE(VARCHAR(XML2CLOB(XMLAGG(XMLELEMENT(NAME "A",ALIASNAME.ATTRIBUTENAME)))),'', ',') AS TRANSPOSED_OUTPUT
NVL(TRIM(',' FROM REPLACE(REPLACE(REPLACE(CAST(XML2CLOB(XMLAGG(XMLELEMENT(NAME "E", ALIASNAME.ATTRIBUTENAME))) AS VARCHAR(100)),'',' '),'',','), '', 'Nothing')), 'Nothing') as TRANSPOSED_OUTPUT
RTRIM(REPLACE(REPLACE(REPLACE(VARCHAR(XMLSERIALIZE(XMLAGG(XMLELEMENT(NAME "A",ALIASNAME.ATTRIBUTENAME) ORDER BY ALIASNAME.ATTRIBUTENAME) AS CLOB)), '',','),'',''),'','')) AS TRANSPOSED_OUTPUT
Make sure you are casting your "ATTRIBUTENAME" to varchar in a subquery and then calling it here.

other possibility, with recursive cte
with tablewithrank as (
select id, category, rownumber() over(partition by category order by id) as rangid , (select count(*) from myTable f2 where f1.category=f2.category) nbidbycategory
from myTable f1
),
cte (id, category, rangid, nbidbycategory, rangconcat) as (
select id, category, rangid, nbidbycategory, cast(id as varchar(500)) from tablewithrank where rangid=1
union all
select f2.id, f2.category, f2.rangid, f2.nbidbycategory, cast(f1.rangconcat as varchar(500)) || ',' || cast(f2.id as varchar(500)) from cte f1 inner join tablewithrank f2 on f1.rangid=f2.rangid -1 and f1.category=f2.category
)
select category, rangconcat as IDS from cte
where rangid=nbidbycategory

Try this:
SELECT GROUP_CONCAT( field1, field2, field3 ,field4 SEPARATOR ', ')

DB2 Comma Separated Output by Groups

Is there a built in function for comma separated column values in DB2 SQL?
Example: If there are columns with an ID and it has 3 rows with the same ID but have three different roles, the data should be concatenated with a comma.
ID | Role
------------
4555 | 2
4555 | 3
4555 | 4
The output should look like the following, per row:
4555 2,3,4

LISTAGG function is new function in DB2 LUW 9.7
see example:
create table myTable (id int, category int);
insert into myTable values (1, 1);
insert into myTable values (2, 2);
insert into myTable values (5, 1);
insert into myTable values (3, 1);
insert into myTable values (4, 2);
example: select without any order in grouped column
select category, LISTAGG(id, ', ') as ids from myTable group by category;
result:
CATEGORY IDS
--------- -----
1 1, 5, 3
2 2, 4
example: select with order by clause in grouped column
select
category,
LISTAGG(id, ', ') WITHIN GROUP(ORDER BY id ASC) as ids
from myTable
group by category;
result:
CATEGORY IDS
--------- -----
1 1, 3, 5
2 2, 4

I think with this smaller query, you can do what you want.
This is equivalent of MySQL's GROUP_CONCAT in DB2.
SELECT
NUM,
SUBSTR(xmlserialize(xmlagg(xmltext(CONCAT( ', ',ROLES))) as VARCHAR(1024)), 3) as ROLES
FROM mytable
GROUP BY NUM;
This will output something like:
NUM ROLES
---- -------------
1 111, 333, 555
2 222, 444
assumming your original result was something like that:
NUM ROLES
---- ---------
1 111
2 222
1 333
2 444
1 555

Depending of the DB2 version you have, you can use XML functions to achieve this.
Example table with some data
create table myTable (id int, category int);
insert into myTable values (1, 1);
insert into myTable values (2, 2);
insert into myTable values (3, 1);
insert into myTable values (4, 2);
insert into myTable values (5, 1);
Aggregate results using xml functions
select category,
xmlserialize(XMLAGG(XMLELEMENT(NAME "x", id) ) as varchar(1000)) as ids
from myTable
group by category;
results:
CATEGORY IDS
-------- ------------------------
1 <x>1</x><x>3</x><x>5</x>
2 <x>2</x><x>4</x>
Use replace to make the result look better
select category,
replace(
replace(
replace(
xmlserialize(XMLAGG(XMLELEMENT(NAME "x", id) ) as varchar(1000))
, '</x><x>', ',')
, '<x>', '')
, '</x>', '') as ids
from myTable
group by category;
Cleaned result
CATEGORY IDS
-------- -----
1 1,3,5
2 2,4
Just saw a better solution using XMLTEXT instead of XMLELEMENT here.

Since DB2 9.7.5 there is a function for that:
LISTAGG(colname, separator)
check this for more information: Using LISTAGG to Turn Rows of Data into a Comma Separated List

My problem was to transpose row fields(CLOB) to column(VARCHAR) with a CSV and use the transposed table for reporting. Because transposing on report layer slows down the report.
One way to go is to use recursive SQL. You can find many articles about that but its difficult and resource consuming if you want to join all your recursive transposed columns.
I created multiple global temp tables where I stored single transposed columns with one key identifier. Eventually, I had 6 temp tables for joining 6 columns but due to limited resource allocation I wasnt able to bring all columns together. I opted to below 3 formulas and then I just had to run 1 query which gave me output in 10 seconds.
I found various articles on using XML2CLOB functions and have found 3 different ways.
REPLACE(VARCHAR(XML2CLOB(XMLAGG(XMLELEMENT(NAME "A",ALIASNAME.ATTRIBUTENAME)))),'', ',') AS TRANSPOSED_OUTPUT
NVL(TRIM(',' FROM REPLACE(REPLACE(REPLACE(CAST(XML2CLOB(XMLAGG(XMLELEMENT(NAME "E", ALIASNAME.ATTRIBUTENAME))) AS VARCHAR(100)),'',' '),'',','), '', 'Nothing')), 'Nothing') as TRANSPOSED_OUTPUT
RTRIM(REPLACE(REPLACE(REPLACE(VARCHAR(XMLSERIALIZE(XMLAGG(XMLELEMENT(NAME "A",ALIASNAME.ATTRIBUTENAME) ORDER BY ALIASNAME.ATTRIBUTENAME) AS CLOB)), '',','),'',''),'','')) AS TRANSPOSED_OUTPUT
Make sure you are casting your "ATTRIBUTENAME" to varchar in a subquery and then calling it here.

other possibility, with recursive cte
with tablewithrank as (
select id, category, rownumber() over(partition by category order by id) as rangid , (select count(*) from myTable f2 where f1.category=f2.category) nbidbycategory
from myTable f1
),
cte (id, category, rangid, nbidbycategory, rangconcat) as (
select id, category, rangid, nbidbycategory, cast(id as varchar(500)) from tablewithrank where rangid=1
union all
select f2.id, f2.category, f2.rangid, f2.nbidbycategory, cast(f1.rangconcat as varchar(500)) || ',' || cast(f2.id as varchar(500)) from cte f1 inner join tablewithrank f2 on f1.rangid=f2.rangid -1 and f1.category=f2.category
)
select category, rangconcat as IDS from cte
where rangid=nbidbycategory

Try this:
SELECT GROUP_CONCAT( field1, field2, field3 ,field4 SEPARATOR ', ')

Adding Row Numbers To a SELECT Query Result in SQL Server Without use Row_Number() function

i need Add Row Numbers To a SELECT Query without using Row_Number() function.
and without using user defined functions or stored procedures.
Select (obtain the row number) as [Row], field1, field2, fieldn from aTable
UPDATE
i am using SAP B1 DIAPI, to make a query , this system does not allow the use of rownumber() function in the select statement.
Bye.

I'm not sure if this will work for your particular situation or not, but can you execute this query with a stored procedure? If so, you can:
A) Create a temp table with all your normal result columns, plus a Row column as an auto-incremented identity.
B) Select-Insert your original query, sans the row column (SQL will fill this in automatically for you)
C) Select * on the temp table for your result set.
Not the most elegant solution, but will accomplish the row numbering you are wanting.

This query will give you the row_number,
SELECT
(SELECT COUNT(*) FROM #table t2 WHERE t2.field <= t1.field) AS row_number,
field,
otherField
FROM #table t1
but there are some restrictions when you want to use it. You have to have one column in your table (in the example it is field) which is unique and numeric and you can use it as a reference. For example:
DECLARE #table TABLE
(
field INT,
otherField VARCHAR(10)
)
INSERT INTO #table(field,otherField) VALUES (1,'a')
INSERT INTO #table(field,otherField) VALUES (4,'b')
INSERT INTO #table(field,otherField) VALUES (6,'c')
INSERT INTO #table(field,otherField) VALUES (7,'d')
SELECT * FROM #table
returns
field | otherField
------------------
1 | a
4 | b
6 | c
7 | d
and
SELECT
(SELECT COUNT(*) FROM #table t2 WHERE t2.field <= t1.field) AS row_number,
field,
otherField
FROM #table t1
returns
row_number | field | otherField
-------------------------------
1 | 1 | a
2 | 4 | b
3 | 6 | c
4 | 7 | d
This is the solution without functions and stored procedures, but as I said there are the restrictions. But anyway, maybe it is enough for you.

RRUZ, you might be able to hide the use of a function by wrapping your query in a View. It would be transparent to the caller. I don't see any other options, besides the ones already mentioned.