I am trying to create a delimitted string from the results of a query in DB2 on the iSeries (AS/400). I've done this in T-SQL, but can't find a way to do it here.
Here is my code in T-SQL. I'm looking for an equivelant in DB2.
DECLARE #a VARCHAR(1000)
SELECT #a = COALESCE(#a + ', ' + [Description], [Description])
FROM AP.Checkbooks
SELECT #a
If the descriptions in my table look like this:
Desc 1
Desc 2
Desc 3
Then it will return this:
Desc 1, Desc 2, Desc 3
Essentially you're looking for the equivalent of MySQL's GROUP_CONCAT aggregate function in DB2. According to one thread I found, you can mimic this behaviour by going through the XMLAGG function:
create table t1 (num int, color varchar(10));
insert into t1 values (1,'red'), (1,'black'), (2,'red'), (2,'yellow'), (2,'green');
select num,
substr( xmlserialize( xmlagg( xmltext( concat( ', ', color ) ) ) as varchar( 1024 ) ), 3 )
from t1
group by num;
This would return
1 red,black
2 red,yellow,green
(or should, if I'm reading things correctly)
You can do this using common table expressions (CTEs) and recursion.
with
cte1 as
(select description, row_number() over() as row_nbr from checkbooks),
cte2 (list, cnt, cnt_max) AS
(SELECT VARCHAR('', 32000), 0, count(description) FROM cte1
UNION ALL
SELECT
-- No comma before the first description
case when cte2.list = '' THEN RTRIM(CHAR(cte1.description))
else cte2.list || ', ' || RTRIM(CHAR(cte1.description)) end,
cte2.cnt + 1,
cte2.cnt_max
FROM cte1,cte2
WHERE cte1.row_nbr = cte2.cnt + 1 AND cte2.cnt < cte2.cnt_max ),
cte3 as
(select list from cte2
where cte2.cnt = cte2.cnt_max fetch first 1 row only)
select list from cte3;
I'm trying to do this in OLEDB and from what I understand you can't do this because you can't do anything fancy in SQL for OLEDB like declare variables or create a table. So I guess there is no way.
If you are running DB2 9.7 or higher, you can use LISTAGG function. Have a look here:
http://pic.dhe.ibm.com/infocenter/db2luw/v9r7/index.jsp?topic=%2Fcom.ibm.db2.luw.sql.ref.doc%2Fdoc%2Fr0058709.html
Related
We have this column in the table named "pricehistory"
1634913730;48.38,1634916509;48.38,1635162352;37.96,1635177904;49.14,1635337722;1219.98,1635340811;27.17
that is an example data.
first is the timestamp than after ; is the price at this timestamp
But i want the average price from every timestamp in a select... is that possible?
I dont find any similiar examples somewhere and my tries to select doesnt work... i am not so good with sql
so i want average of all prices behind that ; and before ,
The , split the timestamp and prices
Some test data :
create table test ( id int not null, pricehistory text not null );
insert into test values ( 1, '1634913730;48.38,1634916509;48.38,1635162352;37.96,1635177904;49.14,1635337722;1219.98,1635340811;27.17' );
insert into test values ( 2, '1634913731;42.42,1634916609;21.21' );
If your RDBMS has some splitting function
Then it's quite easy, just split and use AVG. Here is an example using PostgreSQL :
SELECT id, AVG(SUBSTRING(v, 12, 42)::decimal) AS average
FROM test
INNER JOIN LATERAL regexp_split_to_table(pricehistory, E',') t(v) ON TRUE
GROUP BY id;
Then you get:
id | average
----+----------------------
2 | 31.8150000000000000
1 | 238.5016666666666667
(2 rows)
Otherwise
You can use a CTE to split the values manually. This is a bit more involved. Here is an example using PostgreSQL again :
WITH RECURSIVE T AS (
SELECT id,
-- We get the last value ...
SUBSTRING(pricehistory, LENGTH(pricehistory) - STRPOS(REVERSE(pricehistory), ',') + 2) AS oneprice,
pricehistory AS remaining
FROM test
UNION ALL
-- ... as we get the other values from the recursive CTE.
SELECT id,
LEFT(remaining, STRPOS(remaining, ',') - 1),
SUBSTRING(remaining, STRPOS(remaining, ',') + 1)
FROM T
WHERE STRPOS(remaining, ',') > 0
)
SELECT id, AVG(SUBSTRING(oneprice, 12)::decimal) AS average
FROM T
GROUP BY id;
Then you get:
id | average
----+----------------------
2 | 31.8150000000000000
1 | 238.5016666666666667
(2 rows)
MySql >= 8.0
I used Recursive Common Table Expressions (cte) to split pricehistory string by ','. Then I split price from timestamp by ';', cast price as decimal(10,2) and group by id to get average price by id.
WITH RECURSIVE
cte AS (SELECT id,
SUBSTRING_INDEX(pricehistory, ',', 1) AS price,
CASE WHEN POSITION(',' IN pricehistory) > 0
THEN SUBSTR(pricehistory, POSITION(',' IN pricehistory) + 1)
ELSE NULL END AS rest
FROM t
UNION ALL
SELECT id,
SUBSTRING_INDEX(rest, ',', 1) AS price,
CASE WHEN POSITION(',' IN rest) > 0
THEN SUBSTR(rest, POSITION(',' IN rest) + 1)
ELSE NULL END AS rest
FROM cte
WHERE rest IS NOT NULL)
SELECT id, AVG(CAST(SUBSTR(price, POSITION(';' IN price) + 1) AS decimal(10,2))) AS price_average
FROM cte
GROUP BY id;
A similar way to do the same (using regular expressions functions):
WITH RECURSIVE
cte AS (SELECT Id, concat(pricehistory, ',') AS pricehistory FROM t),
unnest AS (SELECT id,
pricehistory,
1 AS i,
REGEXP_SUBSTR(pricehistory, ';[0-9.]*,', 1, 1) AS price
FROM cte
UNION ALL
SELECT id,
pricehistory,
i + 1,
REGEXP_SUBSTR(pricehistory, ';[0-9.]*,', 1, i + 1)
FROM unnest
WHERE REGEXP_SUBSTR(pricehistory, ';[0-9.]*,', 1, i + 1) IS NOT NULL)
SELECT id, AVG(CAST(SUBSTR(price, 2, LENGTH(price) - 2) AS decimal(10,2))) AS price_average
FROM unnest
GROUP BY id;
you don't write what DBMS you are using.
In MS SQL-SERVER you can write something like this.
Create a function to convert string to multiple rows, and then use that in the query.
CREATE or ALTER FUNCTION dbo.BreakStringIntoRows (#CommadelimitedString varchar(1000), #Separator VARCHAR(1))
RETURNS #Result TABLE (Column1 VARCHAR(max))
AS
BEGIN
DECLARE #IntLocation INT
WHILE (CHARINDEX(#Separator, #CommadelimitedString, 0) > 0)
BEGIN
SET #IntLocation = CHARINDEX(#Separator, #CommadelimitedString, 0)
INSERT INTO #Result (Column1)
--LTRIM and RTRIM to ensure blank spaces are removed
SELECT RTRIM(LTRIM(SUBSTRING(#CommadelimitedString, 0, #IntLocation)))
SET #CommadelimitedString = STUFF(#CommadelimitedString, 1, #IntLocation, '')
END
INSERT INTO #Result (Column1)
SELECT RTRIM(LTRIM(#CommadelimitedString))--LTRIM and RTRIM to ensure blank spaces are removed
RETURN
END
create table test1 ( id int not null, pricehistory varchar(max) not null );
insert into test1 values ( 1, '1634913730;48.38,1634916509;48.38,1635162352;37.96,1635177904;49.14,1635337722;1219.98,1635340811;27.17' );
insert into test1 values ( 2, '1634913731;42.42,1634916609;21.21' );
Select *,
(
Select avg(CAST(RTRIM(LTRIM(SUBSTRING(column1, 0, CHARINDEX(';', column1, 0)))) as decimal)) From dbo.BreakStringIntoRows(pricehistory, ',')
) as AVG
FRom test1
sample output:
Is there a way to generate a comma-separated string of a series of numbers where the "begin" and "end" numbers are provided?
For example, provide the numbers 1 and 10 and the output would be a single value of: 1,2,3,4,5,6,7,8,9,10
10/10/2019 edit explaining why I'm interested in this:
My workplace writes queries with several columns in the SELECT statement plus aggregate functions. Then a GROUP BY clause using the column numbers. I figured using a macro that creates a comma-separated list to copy/paste in would save some time.
SELECT t.colA
, t.colB
, t.colC
, t.colD
, t.colE
, t.colF
, t.colG
, t.colH
, t.colI
, t.colJ
, sum(t.colK) as sumK
, sum(t.colL) as sumL
, sum(t.colM) as sumM
FROM t
GROUP BY 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
;
You can use a recursive CTE to generate your numbers, and xml_agg to generate your string:
with recursive nums (counter) as
( select * from (select cast(1 as bigint) as counter) t
union all
select
counter + 1
from nums
where counter between 1 and 9
)
select
trim(trailing ',' from cast(xmlagg(cast(counter as varchar(2)) || ',' order by counter) as varchar(100)))
from nums
Check these methods in SQL Server-
IF OBJECT_ID('TEMPDB..#Sample') IS NOT NULL
DROP TABLE #Sample
Create table #Sample
(
NUM int
)
declare #n int
select #n=10
insert into #Sample(NUM)
SELECT NUM FROM (select row_number() over (order by (select null)) AS NUM from sys.columns) A WHERE NUM<=#N
--Method 1 (For SQL SERVER -NEW VERSION Support)
SELECT STRING_AGG(NUM,',') AS EXPECTED_RESULT FROM #Sample
--Method 1 (For SQL SERVER -OLD VERSION Support)
select DISTINCT STUFF(CAST((
SELECT ' ,' +CAST(c.num AS VARCHAR(MAX))
FROM (
SELECT num
FROM #Sample
) c
FOR XML PATH(''), TYPE) AS VARCHAR(MAX)), 1, 2, '') AS EXPECTED_RESULT
from #Sample t
While loop seems appropriate
declare #begin int=1
declare #end int=11
declare #list varchar(500)
if #begin > #end
begin
select 'error, beginning number ' + convert(varchar(500),#begin)
+ ' must not be greater than ending number '
+ convert(varchar(500),#end) + '.' err
return
end
else
set #list = convert(varchar(500),#begin)
;
while #begin < #end
begin
set #begin += 1
set #list = #list + ',' + convert(varchar(500),#begin)
end
select #list
You might want to use varchar(5000) or something depending on how big you want it to get.
disclaimer -- I don't know if this works with teradata
I'm not sure there is a good direct way to generate a series in Teradata. You can fake it a few different ways though. Here's a comma separated list of numbers from 5 to 15, for example:
SELECT TRIM(TRAILING ',' FROM (XMLAGG(TRIM(rn)|| ',' ) (VARCHAR(10000))))
FROM (SELECT 4 + ROW_NUMBER() OVER (ORDER BY Sys_Calendar."CALENDAR".day_of_calendar) as rn FROM Sys_Calendar."CALENDAR" QUALIFY rn <= 15) t
I've only used sys_calendar.calendar here because it's a big table. Any big table would do here though.
Here's one way to do it in Teradata:
SELECT ARRAY_AGG(src.RowNum)
FROM (
SELECT ROW_NUMBER() OVER() AS RowNum
FROM sys_calendar.calendar
QUALIFY RowNum BETWEEN <begin_num> AND <end_num>
) src
This will give you the output as an ARRAY data type, which you can probably cast as a VARCHAR. It also assumes begin_num > 0 and <end_num> is less than the number of rows in the sys_calendar.calendar view. You can always fiddle with this to fit your required range of values.
There are also DelimitedBuild UDFs out there (if you can find one) that can be used to convert row values into delimited strings.
The cheapest way to achieve your goal is this one (no functions, or joins to tables required):
WITH RECURSIVE NumberRanges(TheNumber,TheString) AS
(
SELECT 1 AS TheNumber,casT(1 as VARCHAR(500)) as TheString
FROM
(
SELECT * FROM (SELECT NULL AS X) X
) DUMMYTABLE
UNION ALL
SELECT
TheNumber + 1 AS TheNumber,
TheString ||',' || TRIM(TheNumber+1)
FROM NumberRanges
WHERE
TheNumber < 10
)
SELECT TheString
FROM NumberRanges
QUALIFY ROW_NUMBER() OVER ( ORDER BY TheNumber DESC) = 1;
Result String: 1,2,3,4,5,6,7,8,9,10
I have two columns in a table. I want to merge them into a single column, but the merge should be done taking alternate characters from each columns.
For example:
Column A --> value (1,2,3)
Column B --> value (A,B,C)
Required result - (1,A,2,B,3,C)
It should be done without loops.
You need to make use of the UNION and get a little creative with how you choose to alternate. My solution ended up looking like this.
SELECT ColumnA
FROM Table
WHERE ColumnA%2=1
UNION
SELECT ColumnB
FROM TABLE
WHERE ColumnA%2=0
If you have an ID/PK column that could just as easily be used, I just didn't want to assume anything about your table.
EDIT:
If your table contains duplicates that you wish to keep, use UNION ALL instead of UNION
Try This;
SELECT [value]
FROM [Table]
UNPIVOT
(
[value] FOR [Column] IN ([Column_A], [Column_B])
) UNPVT
If you have SQL 2016 or higher you can use:
SELECT QUOTENAME(STRING_AGG (cast(a as varchar(1)) + ',' + b, ','), '()')
FROM test;
In older versions, depending on how much data you have in your tables you can also try:
SELECT QUOTENAME(STUFF(
(SELECT ',' + cast(a as varchar(1)) + ',' + b
FROM test
FOR XML PATH('')), 1, 1,''), '()')
Here you can try a sample
http://sqlfiddle.com/#!18/6c9af/5
with data as (
select *, row_number() over order by colA) as rn
from t
)
select rn,
case rn % 2 when 1 then colA else colB end as alternating
from data;
The following SQL uses undocumented aggregate concatenation technique. This is described in Inside Microsoft SQL Server 2008 T-SQL Programming on page 33.
declare #x varchar(max) = '';
declare #t table (a varchar(10), b varchar(10));
insert into #t values (1,'A'), (2,'B'),(3,'C');
select #x = #x + a + ',' + b + ','
from #t;
select '(' + LEFT(#x, LEN(#x) - 1) + ')';
It's my data and every ThroughRouteSid record has the same pattern.
six number and five comma. then I just want to get three and five
number into two record to template Table and get the same Count()
value to these two record.
For example: First record in the picture.
ThroughRouteSid(3730,2428,2428,3935,3935,3938,) Count(32).
I want a result like this:
2428 32 3935 32
I get What number I want.become two record and both have same Count value into template table
you can use XML to get your result, please refer below sample code -
create table #t1( ThroughRouteSid varchar(500) , Cnt int)
insert into #t1
select '3730,2428,2428,3935,3935,3938,' , len('3730,2428,2428,3935,3935,3938,')
union all select '1111,2222,3333,4444,5555,6666,' , len('1111,2222,3333,4444,5555,6666,')
select cast( '<xml><td>' + REPLACE( SUBSTRING(ThroughRouteSid ,1 , len(ThroughRouteSid)-1),',','</td><td>') + '</td></xml>' as xml) XmlData , Cnt
into #t2 from #t1
select XmlData.value('(xml/td)[3]' ,'int' ), Cnt ,XmlData.value('(xml/td)[5]' ,'int' ), Cnt
from #t2
First create the function referring How to Split a string by delimited char in SQL Server. Then try Querying the following
select (SELECT CONVERT(varchar,splitdata) + ' '+ Convert(varchar, [Count])+' ' FROM (select splitdata, ROW_NUMBER() over (ORDER BY (SELECT 100)) row_no
from [dbo].[fnSplitString](ThroughRouteSid,',')
where splitdata != '') as temp where row_no in (2,5)
for xml path('')) as col1 from [yourtable]
If you are using SQL Server 2016 you can do something like this:
create table #temp (ThroughRouteSid varchar(1024),[Count] int)
insert into #temp values
('3730,2428,2428,3935,3935,3938,',32),
('730,428,428,335,935,938,',28)
select
spt.value,
t.[Count]
from #temp t
cross apply (
select value from STRING_SPLIT(t.ThroughRouteSid,',') where LEN(value) > 0
)spt
I'm converting a stored procedure from MySql to SQL Server. The procedure has one input parameter nvarchar/varchar which is a comma-separated string, e.g.
'1,2,5,456,454,343,3464'
I need to write a query that will retrieve the relevant rows, in MySql I'm using FIND_IN_SET and I wonder what the equivalent is in SQL Server.
I also need to order the ids as in the string.
The original query is:
SELECT *
FROM table_name t
WHERE FIND_IN_SET(id,p_ids)
ORDER BY FIND_IN_SET(id,p_ids);
The equivalent is like for the where and then charindex() for the order by:
select *
from table_name t
where ','+p_ids+',' like '%,'+cast(id as varchar(255))+',%'
order by charindex(',' + cast(id as varchar(255)) + ',', ',' + p_ids + ',');
Well, you could use charindex() for both, but the like will work in most databases.
Note that I've added delimiters to the beginning and end of the string, so 464 will not accidentally match 3464.
You would need to write a FIND_IN_SET function as it does not exist. The closet mechanism I can think of to convert a delimited string into a joinable object would be a to create a table-valued function and use the result in a standard in statement. It would need to be similar to:
DECLARE #MyParam NVARCHAR(3000)
SET #MyParam='1,2,5,456,454,343,3464'
SELECT
*
FROM
MyTable
WHERE
MyTableID IN (SELECT ID FROM dbo.MySplitDelimitedString(#MyParam,','))
And you would need to create a MySplitDelimitedString type table-valued function that would split a string and return a TABLE (ID INT) object.
A set based solution that splits the id's into ints and join with the base table which will make use of index on the base table id. I assumed the id would be an int, otherwise just remove the cast.
declare #ids nvarchar(100) = N'1,2,5,456,454,343,3464';
with nums as ( -- Generate numbers
select top (len(#ids)) row_number() over (order by (select 0)) n
from sys.messages
)
, pos1 as ( -- Get comma positions
select c.ci
from nums n
cross apply (select charindex(',', #ids, n.n) as ci) c
group by c.ci
)
, pos2 as ( -- Distinct posistions plus start and end
select ci
from pos1
union select 0
union select len(#ids) + 1
)
, pos3 as ( -- add row number for join
select ci, row_number() over (order by ci) as r
from pos2
)
, ids as ( -- id's and row id for ordering
select cast(substring(#ids, p1.ci + 1, p2.ci - p1.ci - 1) as int) id, row_number() over (order by p1.ci) r
from pos3 p1
inner join pos3 p2 on p2.r = p1.r + 1
)
select *
from ids i
inner join table_name t on t.id = i.id
order by i.r;
You can also try this by using regex to get the input values from comma separated string :
select * from table_name where id in (
select regexp_substr(p_ids,'[^,]+', 1, level) from dual
connect by regexp_substr(p_ids, '[^,]+', 1, level) is not null );