I have a requirement to create a table with an identifier column. The identifier data will be comprised of 3 parts, the first being a letter [A-Z], the second being a number [1-42] and the third being again a number [1-6].
I was wondering the quickest and best way to go about this as I'm really stuck. The output should look like this:
A-1-1
A-1-2
A-1-3
...
Z-42-6
Thanks for your help
You should use CROSS JOIN with derived tables containing all letters/numbers needed
SELECT letters.let + '-' + numbers.num + '-' + numbers2.num
FROM(SELECT 'A' as let UNION ALL SELECT 'B' .....) letters
CROSS JOIN(SELECT '1' as num UNION ALL SELECT '2' ....) numbers -- up to 42
CROSS JOIN(SELECT '1' as num UNION ALL SELECT '2' ....) numbers2 -- up to 6
Here is a cut-down version using CROSS JOIN acrross 3 valued tables
SELECT v1.val + '-' + CAST(v2.val AS VARCHAR(5)) + '-' + cast(v3.val AS VARCHAR(5))
FROM
(VALUES ('A'),('B'),('C'),('D')) v1(val)
CROSS JOIN
(VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11),(12),(13),(14),(15),(16)) v2(val)
CROSS JOIN
(VALUES (1),(2),(3),(4),(5),(6)) v3(val)
A Tally table would save you the need to write all the values one by one.
If you don't already have a tally table, read this post on the best way to create one.
SELECT Letter +'-'+ cast(fn as varchar(2)) +'-'+ cast(sn as char(1))
FROM (SELECT CHAR(Number) As Letter FROM Tally WHERE Number BETWEEN 65 AND 90) a
CROSS JOIN (SELECT Number as fn FROM Tally WHERE Number BETWEEN 1 AND 42) b
CROSS JOIN (SELECT Number as sn FROM Tally WHERE Number BETWEEN 1 AND 6) c
Just for fun, a mathematical approach:
with cte as
(
select 0 nr
union all
select nr+1 from cte where nr < 6551 --(26 * 42 * 6 = 6552 , 0 based = 6551)
)
select char(65 + (nr / 252)), 1 + ((nr / 6) % 42), 1 + nr % 6, * from cte -- Letter: divider = 6 * 42 = 252 , 65 = 'A'
option (maxrecursion 10000)
The cte only generated a stream of numbers from 0 to 6551 (could be done with other approaches as well).
After that each segment of the sequence can be calculated.
But for the record, once a sequence is created, I like Zohar's solution best :)
One more way:
;WITH cte AS (
SELECT 1 as digit
UNION ALL
SELECT digit + 1
FROM cte
WHERE digit < 90
)
SELECT CHAR(c1.digit) + '-' +
CAST(c2.digit as nvarchar(2)) + '-' +
CAST(c3.digit as nvarchar(2)) as seq
FROM cte c1
CROSS JOIN (SELECT digit FROM cte WHERE digit between 1 and 42) c2
CROSS JOIN (SELECT digit FROM cte WHERE digit between 1 and 6) c3
WHERE c1.digit between 65 and 90 --65..90 in ASCII is A..Z
Output:
seq
A-1-1
A-1-2
A-1-3
A-1-4
A-1-5
A-1-6
A-2-1
A-2-2
A-2-3
A-2-4
A-2-5
A-2-6
...
Z-42-3
Z-42-4
Z-42-5
Z-42-6
Related
I have a table like this:
ItemID ItemFormula
100 'ID_3+ID_5'
110 'ID_2+ID_6'
120 'ID_100+ID_110'
130 'ID_120+ID_4'
This is the simplified version of a formula table with nearly 1000 records and up to 40 levels of reference (items used in other items). The task is breaking down the formulas to just one level reference where no other items are in one item. For example in the table above for id=130 I should have '((ID_3+ID_5)+(ID_2+ID_6))+ID_4'
EDIT: The operations do not limit to "+" and items have a character between them to be recognizable. For the sake of simplicity, I removed that character.
I can use recursive CTE for that. but my problem is that due to high levels of reference, my recursive select has lots of records joining so it takes a lot to complete.
My question is that: Can I keep the previous recursion only each time the recursion happens?
Here is my CTE Code
WITH Formula
AS (SELECT A.ItemID
,'ID_' + CONVERT(VARCHAR(20), A.ItemID) AS ItemText
,CONVERT(VARCHAR(MAX), A.ItemFormula) AS ItemFormula
FROM (VALUES (100,'ID_3+ID_5'),
(110,'ID_2+ID_6'),
(120,'ID_100+ID_110'),
(130,'ID_120+ID_4')
) A (ItemID,ItemFormula)
)
,REC
AS
(
SELECT A.ItemID
,A.ItemText
,A.ItemFormula
,1 AS LevelID
FROM Formula A
UNION ALL
SELECT A.ItemID
,A.ItemText
,' '
+ TRIM (REPLACE (REPLACE (A.ItemFormula, B.ItemText, ' ( ' + B.ItemFormula + ' ) '), ' ', ' '))
+ ' ' AS ItemFormula
,A.LevelID + 1 AS LevelID
FROM REC A
CROSS APPLY
(
SELECT *
FROM
(
SELECT *
,ROW_NUMBER () OVER (ORDER BY GETDATE ()) AS RowNum
FROM Formula B2
WHERE CHARINDEX (B2.ItemText, A.ItemFormula) > 0
) B3
WHERE B3.RowNum = 1
) B
)
,FinalQ
AS
(
SELECT A2.ItemID
,A2.ItemFormula
,A2.LevelID
FROM
(
SELECT A.ItemID
,REPLACE (TRIM (A.ItemFormula), ' ', '') AS ItemFormula
,A.LevelID
,ROW_NUMBER () OVER (PARTITION BY A.ItemID ORDER BY A.LevelID DESC) AS RowNum
FROM REC A
) A2
WHERE A2.RowNum = 1
)
SELECT * FROM FinalQ A2 ORDER BY A2.ItemID;
Thanks in advance.
My question is that: Can I keep the previous recursion only each time the recursion happens?
No. The recursive CTE will keep adding rows to the ones found in previous iterations. You don't have some kind of control that would allow you to remove rows of the recursive CTE during its iterations.
You can, however, filter them out after the recursive CTE is complete, maybe on a secondary CTE that takes into account only the last meaninful rows (by some kind of rule to be defined).
The only vaguely similar idea is found in PostgreSQL where you can use the UNION clause in addition to UNION ALL, to avoid producing more identical rows. But this is different to what you need, anyway.
This is an enormously complicated problem. Here are the ideas:
Find which items do not need any insertions. These are the ones that have no references to any others.
Build an ordering for item insertion. An insertion can go into an item, assuming that the item is already defined. A recursive CTE can be used for this.
Enumerate the insertions. Everything from (1) gets a "1". The rest are in order.
Process the insertions in the insertion order.
Here is my solution:
with ordering as (
select itemid, itemtext, itemformula, convert(varchar(max), null) as otheritemtext, 1 as lev
from formula f
where not exists (select 1
from formula f2 join
string_split(f.itemformula, '+') s
on f2.itemtext = s.value
where f2.itemid <> f.itemid
)
union all
select f.itemid, f.itemtext, f.itemformula, convert(varchar(max), s.value), lev + 1
from formula f cross apply
string_split(f.itemformula, '+') s join
ordering o
on o.itemtext = s.value
-- where lev <= 2
),
ordered as (
select distinct o.*,
dense_rank() over (order by (case when lev = 1 then -1 else lev end), (case when lev = 1 then '' else otheritemtext end)) as seqnum
from ordering o
),
cte as (
select o.itemid, o.itemtext, o.itemformula, convert(varchar(max), o.otheritemtext) as otheritemtext,
o.itemformula as newformula, o.seqnum, 1 as lev
from ordered o
where seqnum = 1
union all
select cte.itemid, o.itemtext, o.itemformula, convert(varchar(max), cte.itemtext),
replace(o.itemformula, o.otheritemtext, concat('(', cte.newformula, ')')), o.seqnum, cte.lev + 1
from cte join
ordered o
on cte.itemtext = o.otheritemtext and cte.seqnum < o.seqnum
)
select *
from cte;
And the db<>fiddle.
You could take advantage of the logical order of the formulas if any (Item_100 can not reference Item_150) and process items in a descending order.
The following uses LIKE and it will not work for formulas which have overlapping patterns (eg ID_10 & ID_100) you could fix that by some string manipulation or by keeping ItemIDs of fixed length (eg. ID_10010 & ID_10100: start numbering of items from a high number like 10000)
declare #f table
(
ItemId int,
ItemFormula varchar(1000)
);
insert into #f(ItemId, ItemFormula)
values
(100, 'ID_3+ID_5'),
(110, 'ID_2+ID_6'),
(120, 'ID_100+ID_110'),
(130, 'ID_120+ID_4'),
(140, '(ID_130+ID_110)/ID_100'),
(150, 'sqrt(ID_140, ID_130)'),
(160, 'ID_150-ID_120+ID_140');
;with cte
as
(
select f.ItemId, replace(cast(f.ItemFormula as varchar(max)), isnull('ID_' + cast(r.ItemId as varchar(max)), ''), isnull('(' + r.ItemFormula+ ')', '')) as therepl, 1 as lvl
from #f as f
outer apply (
select *
from
(
select rr.*, row_number() over(order by rr.ItemId desc) as rownum
from #f as rr
where f.ItemFormula like '%ID_' + cast(rr.ItemId as varchar(1000)) + '%'
) as src
where rownum = 1
) as r
union all
select c.ItemId, replace(c.therepl, 'ID_' + cast(r.ItemId as varchar(max)), '(' + r.ItemFormula+ ')'), c.lvl+1
from cte as c
cross apply (
select *
from
(
select rr.*, row_number() over(order by rr.ItemId desc) as rownum
from #f as rr
where c.therepl like '%ID_' + cast(rr.ItemId as varchar(1000)) + '%'
) as src
where rownum = 1
) as r
),
rown
as
(
select *, row_number() over (partition by itemid order by lvl desc) as rownum
from cte
)
select *
from rown
where rownum = 1;
I have a field that contains numbers such as the examples below in #Numbers. Each number within each row in #Numbers relates
to many different values that are contained within the #Area table.
I need to make a relationship from #Numbers to #Area using each number within each row.
CREATE TABLE #Numbers
(
Number int
)
INSERT INTO #Numbers
(
Number
)
SELECT 102 UNION
SELECT 1 UNION
SELECT 2 UNION
select * from #Numbers
CREATE TABLE #Area
(
Number int,
Area varchar(50)
)
INSERT INTO #Area
(
Number,
Area
)
SELECT 0,'Area1' UNION
SELECT 1,'Area2' UNION
SELECT 1,'Area3' UNION
SELECT 1,'Area5' UNION
SELECT 1,'Area8' UNION
SELECT 1,'Area9' UNION
SELECT 2,'Area12' UNION
SELECT 2,'Area43' UNION
SELECT 2,'Area25' UNION
select * from #Area
It would return the following for 102:
102,Area2
102,Area3
102,Area5
102,Area8
102,Area9
102,Area1
102,Area12
102,Area43
102,Area25
For 1 it would return:
1,Area2
1,Area3
1,Area5
1,Area8
1,Area9
For 2 it would return:
2,Area12
2,Area43
2,Area25
Note how the numbers match up to the individual Areas and return the values accordingly.
Well, the OP marked an answer already, which even got votes. Maybe he will not read this, but here is another option using direct simple select, which (according to the EP) seems like using a lot less resources:
SELECT *
FROM #Numbers t1
LEFT JOIN #Area t2 ON CONVERT(VARCHAR(10), t1.Number) like '%' + CONVERT(CHAR(1), t2.Number) + '%'
GO
Note! According to Execution Plan this solution uses only 27% while the selected answer (written by Squirrel) uses 73%, but Execution Plan can be misleading sometimes and you should check IO and TIME statistics as well using the real table structure and real data.
looks like you need to extract individual digit from #Number and then used it to join to #Area
; with tally as
(
select n = 1
union all
select n = n + 1
from tally
where n < 10
)
select n.Number, a.Area
from #Numbers n
cross apply
(
-- here it convert n.Number to string
-- then extract 1 digit
-- and finally convert back to integer
select num = convert(int,
substring(convert(varchar(10), n.Number),
t.n,
1)
)
from tally t
where t.n <= len(convert(varchar(10), n.Number))
) d
inner join #Area a on d.num = a.Number
order by n.Number
or if you prefer to do it in arithmetic and not string
; with Num as
(
select Number, n = 0, Num = Number / power(10, 0) % 10
from #Numbers
union all
select Number, n = n + 1, Num = Number / power(10, n + 1) % 10
from Num
where Number > power(10, n + 1)
)
select n.Number, a.Area
from Num n
inner join #Area a on n.Num = a.Number
order by n.Number
Here is my idea. In theory, it should work.
Have a table (temp or permanent) with the values and it's translation
I.E.
ID value
1 Area1, Area2, Area7, Area8, Area15
2 Area28, Area35
etc
Take each row and put a some special character between each number. Use a function like string_split with that character to turn it into a column of values.
e.g 0123 will then be something like 0|1|2|3 and when you run that through string_split you would get
0
1
2
3
Now join each value to your lookup table and return the Value.
Now you have a row with all the values that you want. Use another function like STUFF FOR XML and put those values back into a single column.
This doesn't sound very efficient.. but this is one way of achieving what you desire..
Another is to do a replace().. but that would be very messy!
Create a third table called n which contains a single column also called n that contains integers from 1 to the maximum number of digits in your number. Make it 1000 if you like, doesn't matter. Then:
select #numbers.number, substring(convert(varchar,#numbers.number),n,1) as chr, Area
from #numbers
join n on n>0 and n <=len(convert(varchar,number))
join #area on #area.number=substring(convert(varchar,#numbers.number),n,1)
The middle column chr is just there to show you what it's doing, and would be removed from the final result.
In DB2, I have this query to list numbers 1-x:
select level from SYSIBM.SYSDUMMY1 connect by level <= "some number"
But this maxes out due to SQL20450N Recursion limit exceeded within a hierarchical query.
How can I generate a list of numbers between 1 and x using a select statement when x is not known at runtime?
I found an answer based on this post:
WITH d AS
(SELECT LEVEL - 1 AS dig FROM SYSIBM.SYSDUMMY1 CONNECT BY LEVEL <= 10)
SELECT t1.n
FROM (SELECT (d7.dig * 1000000) +
(d6.dig * 100000) +
(d5.dig * 10000) +
(d4.dig * 1000) +
(d3.dig * 100) +
(d2.dig * 10) +
d1.dig AS n
FROM d d1
CROSS JOIN d d2
CROSS JOIN d d3
CROSS JOIN d d4
CROSS JOIN d d5
CROSS JOIN d d6
CROSS JOIN d d7) t1
JOIN ("subselect that returns desired value as i") t2
ON t1.n <= t2.i
ORDER BY t1.n
That's how I usually create lists:
For your example
numberlist (num) as
(
select min(1) from anytable
union all
select num + 1 from numberlist
where num <= x
)
I did something like this when I wanted a list of values to correspond with months:
with t1 (mon) as (
values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11),(12)
)
select * from t1
It seems a bit kludgy, but for a small list like 1-12, or even 1-50, it did what I needed it to.
It's nice to see someone else tagging their questions with DB2.
If you have any table known to have more than x rows, you can always do:
select * from (
select row_number() over () num
from my_big_table
) where num <= x
or, per bhamby's suggestion:
select row_number() over () num
from my_big_table
fetch first X rows only
For DB2 you can use recursive common table expressions (cf. IBM documentation on recursive CTE):
with max(num) as (
select 1 from sysibm.sysdummy1
)
,result (num) as (
select num from max
union ALL
select result.num+1
from result
where result.num<=100
)
select * from result;
How to create letter sequence in SQL Server ? Like A,B,C....Z,AA,AB... I refer this
Given Letter, Get Next Letter in Alphabet link but it will not work after letter Z.How to do this?
You can just use arithmetic. This is going to assume that you have numbers in a table (however you want to generate them):
select (case when (n / 26) % 27 = 0 then ''
else char(ascii('A') + (n / 26) % 27 - 1)
end) +
char(ascii('A') + n % 26)
from numbers n;
For instance:
select (case when (n / 26) % 27 = 0 then ''
else char(ascii('A') + (n / 26) % 27 - 1)
end) +
char(ascii('A') + n % 26)
from (select top 100 row_number() over (order by (select null)) - 1 as n
from master..spt_values
) n;
Here is a SQL Fiddle. Longer sequences can be generated using the same logic.
An alternative method is to put together a sequence of letters and then just cross join to put them together:
with letters as (
select top 26
char(ascii('A') + row_number() over (order by (select null)) - 1) as letter
from master..spt_values
)
select l1.letter as seq
from letters l1
union all
select l1.letter + l2.letter
from letters l1 cross join letters l2
union all
select l1.letter + l2.letter + l3.letter
from letters l1 cross join letters l2 cross join letters l3
order by len(seq), seq;
This is a bit challenging because the sequences have different lengths.
Here is a SQL Fiddle illustrating this approach.
here we use generate_series() function to generate a series of number.Specify numbers from where to where you need to generate sequence of numbers. And chr() fucntion returns the ASCII value of those number
from
select chr(generate_series(65,90));
Is there an elegant way in SQL Server to find all the distinct characters in a single varchar(50) column, across all rows?
Bonus points if it can be done without cursors :)
For example, say my data contains 3 rows:
productname
-----------
product1
widget2
nicknack3
The distinct inventory of characters would be "productwigenka123"
Here's a query that returns each character as a separate row, along with the number of occurrences. Assuming your table is called 'Products'
WITH ProductChars(aChar, remain) AS (
SELECT LEFT(productName,1), RIGHT(productName, LEN(productName)-1)
FROM Products WHERE LEN(productName)>0
UNION ALL
SELECT LEFT(remain,1), RIGHT(remain, LEN(remain)-1) FROM ProductChars
WHERE LEN(remain)>0
)
SELECT aChar, COUNT(*) FROM ProductChars
GROUP BY aChar
To combine them all to a single row, (as stated in the question), change the final SELECT to
SELECT aChar AS [text()] FROM
(SELECT DISTINCT aChar FROM ProductChars) base
FOR XML PATH('')
The above uses a nice hack I found here, which emulates the GROUP_CONCAT from MySQL.
The first level of recursion is unrolled so that the query doesn't return empty strings in the output.
Use this (shall work on any CTE-capable RDBMS):
select x.v into prod from (values('product1'),('widget2'),('nicknack3')) as x(v);
Test Query:
with a as
(
select v, '' as x, 0 as n from prod
union all
select v, substring(v,n+1,1) as x, n+1 as n from a where n < len(v)
)
select v, x, n from a -- where n > 0
order by v, n
option (maxrecursion 0)
Final Query:
with a as
(
select v, '' as x, 0 as n from prod
union all
select v, substring(v,n+1,1) as x, n+1 as n from a where n < len(v)
)
select distinct x from a where n > 0
order by x
option (maxrecursion 0)
Oracle version:
with a(v,x,n) as
(
select v, '' as x, 0 as n from prod
union all
select v, substr(v,n+1,1) as x, n+1 as n from a where n < length(v)
)
select distinct x from a where n > 0
Given that your column is varchar, it means it can only store characters from codes 0 to 255, on whatever code page you have. If you only use the 32-128 ASCII code range, then you can simply see if you have any of the characters 32-128, one by one. The following query does that, looking in sys.objects.name:
with cteDigits as (
select 0 as Number
union all select 1 as Number
union all select 2 as Number
union all select 3 as Number
union all select 4 as Number
union all select 5 as Number
union all select 6 as Number
union all select 7 as Number
union all select 8 as Number
union all select 9 as Number)
, cteNumbers as (
select U.Number + T.Number*10 + H.Number*100 as Number
from cteDigits U
cross join cteDigits T
cross join cteDigits H)
, cteChars as (
select CHAR(Number) as Char
from cteNumbers
where Number between 32 and 128)
select cteChars.Char as [*]
from cteChars
cross apply (
select top(1) *
from sys.objects
where CHARINDEX(cteChars.Char, name, 0) > 0) as o
for xml path('');
If you have a Numbers or Tally table which contains a sequential list of integers you can do something like:
Select Distinct '' + Substring(Products.ProductName, N.Value, 1)
From dbo.Numbers As N
Cross Join dbo.Products
Where N.Value <= Len(Products.ProductName)
For Xml Path('')
If you are using SQL Server 2005 and beyond, you can generate your Numbers table on the fly using a CTE:
With Numbers As
(
Select Row_Number() Over ( Order By c1.object_id ) As Value
From sys.columns As c1
Cross Join sys.columns As c2
)
Select Distinct '' + Substring(Products.ProductName, N.Value, 1)
From Numbers As N
Cross Join dbo.Products
Where N.Value <= Len(Products.ProductName)
For Xml Path('')
Building on mdma's answer, this version gives you a single string, but decodes some of the changes that FOR XML will make, like & -> &.
WITH ProductChars(aChar, remain) AS (
SELECT LEFT(productName,1), RIGHT(productName, LEN(productName)-1)
FROM Products WHERE LEN(productName)>0
UNION ALL
SELECT LEFT(remain,1), RIGHT(remain, LEN(remain)-1) FROM ProductChars
WHERE LEN(remain)>0
)
SELECT STUFF((
SELECT N'' + aChar AS [text()]
FROM (SELECT DISTINCT aChar FROM Chars) base
ORDER BY aChar
FOR XML PATH, TYPE).value(N'.[1]', N'nvarchar(max)'),1, 1, N'')
-- Allow for a lot of recursion. Set to 0 for infinite recursion
OPTION (MAXRECURSION 365)