SQL Server: Joining in rows via. comma separated field - sql-server

I'm trying to extract some data from a third party system which uses an SQL Server database. The DB structure looks something like this:
Order
OrderID OrderNumber
1 OX101
2 OX102
OrderItem
OrderItemID OrderID OptionCodes
1 1 12,14,15
2 1 14
3 2 15
Option
OptionID Description
12 Batteries
14 Gift wrap
15 Case
[etc.]
What I want is one row per order item that includes a concatenated field with each option description. So something like this:
OrderItemID OrderNumber Options
1 OX101 Batteries\nGift Wrap\nCase
2 OX101 Gift Wrap
3 OX102 Case
Of course this is complicated by the fact that the options are a comma separated string field instead of a proper lookup table. So I need to split this up by comma in order to join in the options table, and then concat the result back into one field.
At first I tried creating a function which splits out the option data by comma and returns this as a table. Although I was able to join the result of this function with the options table, I wasn't able to pass the OptionCodes column to the function in the join, as it only seemed to work with declared variables or hard-coded values.
Can someone point me in the right direction?

I would use a splitting function (here's an example) to get individual values and keep them in a CTE. Then you can join the CTE to your table called "Option".
SELECT * INTO #Order
FROM (
SELECT 1 OrderID, 'OX101' OrderNumber UNION SELECT 2, 'OX102'
) X;
SELECT * INTO #OrderItem
FROM (
SELECT 1 OrderItemID, 1 OrderID, '12,14,15' OptionCodes
UNION
SELECT 2, 1, '14'
UNION
SELECT 3, 2, '15'
) X;
SELECT * INTO #Option
FROM (
SELECT 12 OptionID, 'Batteries' Description
UNION
SELECT 14, 'Gift Wrap'
UNION
SELECT 15, 'Case'
) X;
WITH N AS (
SELECT I.OrderID, I.OrderItemID, X.items OptionCode
FROM #OrderItem I CROSS APPLY dbo.Split(OptionCodes, ',') X
)
SELECT Q.OrderItemID, Q.OrderNumber,
CONVERT(NVarChar(1000), (
SELECT T.Description + ','
FROM N INNER JOIN #Option T ON N.OptionCode = T.OptionID
WHERE N.OrderItemID = Q.OrderItemID
FOR XML PATH(''))
) Options
FROM (
SELECT N.OrderItemID, O.OrderNumber
FROM #Order O INNER JOIN N ON O.OrderID = N.OrderID
GROUP BY N.OrderItemID, O.OrderNumber) Q
DROP TABLE #Order;
DROP TABLE #OrderItem;
DROP TABLE #Option;

Related

TSQL : Find PAIR Sequence in a table

I have following table in T-SQL(there are other columns too but no identity column or primary key column):
Oid Cid
1 a
1 b
2 f
3 c
4 f
5 a
5 b
6 f
6 g
7 f
So in above example I would like to highlight that following Oid are duplicate when looking at Cid column values as "PAIRS":
Oid:
1 (1 matches Oid: 5)
2 (2 matches Oid: 4 and 7)
Please NOTE that Oid 2 match did not include Oid 6, since the pair of 6 has letter 'G' as well.
Is it possible to create a query without using While loop to highlight the "Oid" like above? along with how many other matches count exist in database?
I am trying to find the patterns within the dataset relating to these two columns. Thank you in Advance.
Here is a worked example - see comments for explanation:
--First set up your data in a temp table
declare #oidcid table (Oid int, Cid char(1));
insert into #oidcid values
(1,'a'),
(1,'b'),
(2,'f'),
(3,'c'),
(4,'f'),
(5,'a'),
(5,'b'),
(6,'f'),
(6,'g'),
(7,'f');
--This cte gets a table with all of the cids in order, for each oid
with cte as (
select distinct Oid, (select Cid + ',' from #oidcid i2
where i2.Oid = i.Oid order by Cid
for xml path('')) Cids
from #oidcid i
)
select Oid, cte.Cids
from cte
inner join (
-- Here we get just the lists of cids that appear more than once
select Cids, Count(Oid) as OidCount
from cte group by Cids
having Count(Oid) > 1 ) as gcte on cte.Cids = gcte.Cids
-- And when we list them, we are showing the oids with duplicate cids next to each other
Order by cte.Cids
select o1.Cid, o1.Oid, o2.Oid
, count(*) + 1 over (partition by o1.Cid) as [cnt]
from table o1
join table o2
on o1.Cid = o2.Cid
and o1.Oid < o2.Oid
order by o1.Cid, o1.Oid, o2.Oid
Maybe Like this then:
WITH CTE AS
(
SELECT Cid, oid
,ROW_NUMBER() OVER (PARTITION BY cid ORDER BY cid) AS RN
,SUM(1) OVER (PARTITION BY oid) AS maxRow2
,SUM(1) OVER (PARTITION BY cid) AS maxRow
FROM oid
)
SELECT * FROM CTE WHERE maxRow != 1 AND maxRow2 = 1
ORDER BY oid

How to check for a specific condition by looping through every record in SQL Server?

I do have following table
ID Name
1 Jagan Mohan Reddy868
2 Jagan Mohan Reddy869
3 Jagan Mohan Reddy
Name column size is VARCHAR(55).
Now for some other task we need to take only 10 varchar length i.e. VARCHAR(10).
My requirement is to check that after taking the only 10 bits length of Name column value for eg if i take Name value of ID 1 i.e. Jagan Mohan Reddy868 by SUBSTRING(Name, 0,11) if it equals with another row value. here in this case the final value of SUBSTRING(Jagan Mohan Reddy868, 0,11) is equal to Name value of ID 3 row whose Name is 'Jagan Mohan Reddy'. I need to make a list of those kind rows. Can somebody help me out on how can i achieve in SQL Server.
My main check is that the truncated values of my Name column should not match with any non truncated values of Name column. If so i need to get those records.
Assuming I understand the question, I think you are looking for something like this:
Create and populate sample data (Please save us this step in your future questions)
DECLARE #T as TABLE
(
Id int identity(1,1),
Name varchar(15)
)
INSERT INTO #T VALUES
('Hi, I am Zohar.'),
('Hi, I am Peled.'),
('Hi, I am Z'),
('I''m Zohar peled')
Use a cte with a self inner join to get the list of ids that match the first 10 chars:
;WITH cte as
(
SELECT T2.Id As Id1, T1.Id As Id2
FROM #T T1
INNER JOIN #T T2 ON LEFT(T1.Name, 10) = t2.Name AND T1.Id <> T2.Id
)
Select the records from the original table, inner joined with a union of the Id1 and Id2 from the cte:
SELECT T.Id, Name
FROM #T T
INNER JOIN
(
SELECT Id1 As Id
FROM CTE
UNION
SELECT Id2
FROM CTE
) U ON T.Id = U.Id
Results:
Id Name
----------- ---------------
1 Hi, I am Zohar.
3 Hi, I am Z
Try this
SELECT Id,Name
FROM(
SELECT *,ROW_NUMBER() OVER(PARTITION BY Name, LEFT(Name,11) ORDER BY ID) RN
FROM Tbale1 T
) Tmp
WHERE Tmp.RN = 1
loop over your column for all the values and put your substring() function inside this loop and I think in Sql index of string starts from 1 instead of 0. If you pass your string to charindex() like this
CHARINDEX('Y', 'Your String')
thus you will come to know whether it is starting from 0 or 1
and you can save your substring value as value of other column with length 10
I hope it will help you..
I think this should cover all the cases you are looking for.
-- Create Table
DECLARE #T as TABLE
(
Id int identity(1,1),
Name varchar(55)
)
-- Create Data
INSERT INTO #T VALUES
('Jagan Mohan Reddy868'),
('Jagan Mohan Reddy869'),
('Jagan Mohan Reddy'),
('Mohan Reddy'),
('Mohan Reddy123551'),
('Mohan R')
-- Get Matching Items
select *, SUBSTRING(name, 0, 11) as ShorterName
from #T
where SUBSTRING(name, 0, 11) in
(
-- get all shortnames with a count > 1
select SUBSTRING(name, 0, 11) as ShortName
from #T
group by SUBSTRING(name, 0, 11)
having COUNT(*) > 1
)
order by Name, LEN(Name)

Creating permutation via recursive CTE in SQL server?

Looking at :
;WITH cte AS(
SELECT 1 AS x UNION
SELECT 2 AS x UNION
SELECT 3 AS x
)
I can create permutation table for all 3 values :
SELECT T1.x , y=T2.x , z=t3.x
FROM cte T1
JOIN cte T2
ON T1.x != T2.x
JOIN cte T3
ON T2.x != T3.x AND T1.x != T3.x
This uses the power of SQL's cartesian product plus eliminating equal values.
OK.
But is it possible to enhance this recursive pseudo CTE :
;WITH cte AS(
SELECT 1 AS x , 2 AS y , 3 AS z
UNION ALL
...
)
SELECT * FROM cte
So that it will yield same result as :
NB there are other solutions in SO that uses recursive CTE , but it is not spread to columns , but string representation of the permutations
I tried to do the lot in a CTE.
However trying to "redefine" a rowset dynamically is a little tricky. While the task is relatively easy using dynamic SQL doing it without poses some issues.
While this answer may not be the most efficient or straight forward, or even correct in the sense that it's not all CTE it may give others a basis to work from.
To best understand my approach read the comments, but it might be worthwhile looking at each CTE expression in turn with by altering the bit of code below in the main block, with commenting out the section below it.
SELECT * FROM <CTE NAME>
Good luck.
IF OBJECT_ID('tempdb..#cteSchema') IS NOT NULL
DROP Table #cteSchema
GO
-- BASE CTE
;WITH cte AS( SELECT 1 AS x, 2 AS y, 3 AS z),
-- So we know what columns we have from the CTE we extract it to XML
Xml_Schema AS ( SELECT CONVERT(XML,(SELECT * FROM cte FOR XML PATH(''))) AS MySchema ),
-- Next we need to get a list of the columns from the CTE, by querying the XML, getting the values and assigning a num to the column
MyColumns AS (SELECT D.ROWS.value('fn:local-name(.)','SYSNAME') AS ColumnName,
D.ROWS.value('.','SYSNAME') as Value,
ROW_NUMBER() OVER (ORDER BY D.ROWS.value('fn:local-name(.)','SYSNAME')) AS Num
FROM Xml_Schema
CROSS APPLY Xml_Schema.MySchema.nodes('/*') AS D(ROWS) ),
-- How many columns we have in the CTE, used a coupld of times below
ColumnStats AS (SELECT MAX(NUM) AS ColumnCount FROM MyColumns),
-- create a cartesian product of the column names and values, so now we get each column with it's possible values,
-- so {x=1, x =2, x=3, y=1, y=2, y=3, z=1, z=2, z=3} -- you get the idea.
PossibleValues AS (SELECT MyC.ColumnName, MyC.Num AS ColumnNum, MyColumns.Value, MyColumns.Num,
ROW_NUMBER() OVER (ORDER BY MyC.ColumnName, MyColumns.Value, MyColumns.Num ) AS ID
FROM MyColumns
CROSS APPLY MyColumns MyC
),
-- Now we have the possibly values of each "column" we now have to concat the values together using this recursive CTE.
AllRawXmlRows AS (SELECT CONVERT(VARCHAR(MAX),'<'+ISNULL((SELECT ColumnName FROM MyColumns WHERE MyColumns.Num = 1),'')+'>'+Value) as ConcatedValue, Value,ID, Counterer = 1 FROM PossibleValues
UNION ALL
SELECT CONVERT(VARCHAR(MAX),CONVERT(VARCHAR(MAX), AllRawXmlRows.ConcatedValue)+'</'+(SELECT ColumnName FROM MyColumns WHERE MyColumns.Num = Counterer)+'><'+(SELECT ColumnName FROM MyColumns WHERE MyColumns.Num = Counterer+1)+'>'+CONVERT(VARCHAR(MAX),PossibleValues.Value)) AS ConcatedValue, PossibleValues.Value, PossibleValues.ID,
Counterer = Counterer+1
FROM AllRawXmlRows
INNER JOIN PossibleValues ON AllRawXmlRows.ConcatedValue NOT LIKE '%'+PossibleValues.Value+'%' -- I hate this, there has to be a better way of making sure we don't duplicate values....
AND AllRawXmlRows.ID <> PossibleValues.ID
AND Counterer < (SELECT ColumnStats.ColumnCount FROM ColumnStats)
),
-- The above made a list but was missing the final closing XML element. so we add it.
-- we also restict the list to the items that contain all columns, the section above builds it up over many columns
XmlRows AS (SELECT DISTINCT
ConcatedValue +'</'+(SELECT ColumnName FROM MyColumns WHERE MyColumns.Num = Counterer)+'>'
AS ConcatedValue
FROM AllRawXmlRows WHERE Counterer = (SELECT ColumnStats.ColumnCount FROM ColumnStats)
),
-- Wrap the output in row and table tags to create the final XML
FinalXML AS (SELECT (SELECT CONVERT(XML,(SELECT CONVERT(XML,ConcatedValue) FROM XmlRows FOR XML PATH('row'))) FOR XML PATH('table') )as XMLData),
-- Prepare a CTE that represents the structure of the original CTE with
DataTable AS (SELECT cte.*, XmlData
FROM FinalXML, cte)
--SELECT * FROM <CTE NAME>
-- GETS destination columns with XML data.
SELECT *
INTO #cteSchema
FROM DataTable
DECLARE #XML VARCHAR(MAX) ='';
SELECT #Xml = XMLData FROM #cteSchema --Extract XML Data from the
ALTER TABLE #cteSchema DROP Column XMLData -- Removes the superflous column
DECLARE #h INT
EXECUTE sp_xml_preparedocument #h OUTPUT, #XML
SELECT *
FROM OPENXML(#h, '/table/row', 2)
WITH #cteSchema -- just use the #cteSchema to define the structure of the xml that has been constructed
EXECUTE sp_xml_removedocument #h
How about translating 1,2,3 into a column, which will look exactly like the example you started from, and use the same approach ?
;WITH origin (x,y,z) AS (
SELECT 1,2,3
), translated (x) AS (
SELECT col
FROM origin
UNPIVOT ( col FOR cols IN (x,y,z)) AS up
)
SELECT T1.x , y=T2.x , z=t3.x
FROM translated T1
JOIN translated T2
ON T1.x != T2.x
JOIN translated T3
ON T2.x != T3.x AND T1.x != T3.x
ORDER BY 1,2,3
If I understood correctly the request, this might just do the trick.
And to run it on more columns, just need to add them origin cte definition + unpivot column list.
Now, i dont know how you pass your 1 - n values for it to be dynamic, but if you tell me, i could try edit the script to be dynamic too.

SQL server logic for fetching data from the table

"Need to display all items linked to the parent category id=1 As per the table, It should fetch:Big Machine, Computer, CPU Cabinet, Hard Disk and Magnetic Disk. But by the logic that is written it is not fetching all the records. Plz help.."
create table ItemSpares
(
ItemName varchar(20),
ItemID int,
ParentCategoryID int
)
insert into ItemSpares (ItemName,ItemID,ParentCategoryID)
select 'Big Machine', 1 , NULL UNION ALL
select 'Computer', 2, 1 UNION ALL
select 'CPU Cabinet', 3, 2 UNION ALL
select 'Hard Disk', 4, 3 UNION ALL
select 'Magnetic Disk',5,4 UNION ALL
select 'Another Big Machine',6, NULL
You need to use a hierarchical SQL query, took a while to figure out but try this:
with BigComputerList (ItemName, ItemID, ParentCategoryID, Level)
AS
(
-- Anchor member definition
SELECT e.ItemName, e.ItemID, e.ParentCategoryID,
0 AS Level
FROM ItemSpares AS e
WHERE ItemID = 1
UNION ALL
-- Recursive member definition
SELECT e.ItemName, e.ItemID, e.ParentCategoryID,
Level + 1
FROM ItemSpares AS e
INNER JOIN BigComputerList AS d
ON e.ParentCategoryId = d.ItemID
)
Select * From BigComputerList
I would highly recommend reading this article if you want to understand what the query is doing.

SQL Select Statement For Calculating A Running Average Column

I am trying to have a running average column in the SELECT statement based on a column from the n previous rows in the same SELECT statement. The average I need is based on the n previous rows in the resultset.
Let me explain
Id Number Average
1 1 NULL
2 3 NULL
3 2 NULL
4 4 2 <----- Average of (1, 3, 2),Numbers from previous 3 rows
5 6 3 <----- Average of (3, 2, 4),Numbers from previous 3 rows
. . .
. . .
The first 3 rows of the Average column are null because there are no previous rows. The row 4 in the Average column shows the average of the Number column from the previous 3 rows.
I need some help trying to construct a SQL Select statement that will do this.
This should do it:
--Test Data
CREATE TABLE RowsToAverage
(
ID int NOT NULL,
Number int NOT NULL
)
INSERT RowsToAverage(ID, Number)
SELECT 1, 1
UNION ALL
SELECT 2, 3
UNION ALL
SELECT 3, 2
UNION ALL
SELECT 4, 4
UNION ALL
SELECT 5, 6
UNION ALL
SELECT 6, 8
UNION ALL
SELECT 7, 10
--The query
;WITH NumberedRows
AS
(
SELECT rta.*, row_number() OVER (ORDER BY rta.ID ASC) AS RowNumber
FROM RowsToAverage rta
)
SELECT nr.ID, nr.Number,
CASE
WHEN nr.RowNumber <=3 THEN NULL
ELSE ( SELECT avg(Number)
FROM NumberedRows
WHERE RowNumber < nr.RowNumber
AND RowNumber >= nr.RowNumber - 3
)
END AS MovingAverage
FROM NumberedRows nr
Assuming that the Id column is sequential, here's a simplified query for a table named "MyTable":
SELECT
b.Id,
b.Number,
(
SELECT
AVG(a.Number)
FROM
MyTable a
WHERE
a.id >= (b.Id - 3)
AND a.id < b.Id
AND b.Id > 3
) as Average
FROM
MyTable b;
Edit: I missed the point that it should average the three previous records...
For a general running average, I think something like this would work:
SELECT
id, number,
SUM(number) OVER (ORDER BY ID) /
ROW_NUMBER() OVER (ORDER BY ID) AS [RunningAverage]
FROM myTable
ORDER BY ID
A simple self join would seem to perform much better than a row referencing subquery
Generate 10k rows of test data:
drop table test10k
create table test10k (Id int, Number int, constraint test10k_cpk primary key clustered (id))
;WITH digits AS (
SELECT 0 as Number
UNION SELECT 1
UNION SELECT 2
UNION SELECT 3
UNION SELECT 4
UNION SELECT 5
UNION SELECT 6
UNION SELECT 7
UNION SELECT 8
UNION SELECT 9
)
,numbers as (
SELECT
(thousands.Number * 1000)
+ (hundreds.Number * 100)
+ (tens.Number * 10)
+ ones.Number AS Number
FROM digits AS ones
CROSS JOIN digits AS tens
CROSS JOIN digits AS hundreds
CROSS JOIN digits AS thousands
)
insert test10k (Id, Number)
select Number, Number
from numbers
I would pull the special case of the first 3 rows out of the main query, you can UNION ALL those back in if you really want it in the row set. Self join query:
;WITH NumberedRows
AS
(
SELECT rta.*, row_number() OVER (ORDER BY rta.ID ASC) AS RowNumber
FROM test10k rta
)
SELECT nr.ID, nr.Number,
avg(trailing.Number) as MovingAverage
FROM NumberedRows nr
join NumberedRows as trailing on trailing.RowNumber between nr.RowNumber-3 and nr.RowNumber-1
where nr.Number > 3
group by nr.id, nr.Number
On my machine this takes about 10 seconds, the subquery approach that Aaron Alton demonstrated takes about 45 seconds (after I changed it to reflect my test source table) :
;WITH NumberedRows
AS
(
SELECT rta.*, row_number() OVER (ORDER BY rta.ID ASC) AS RowNumber
FROM test10k rta
)
SELECT nr.ID, nr.Number,
CASE
WHEN nr.RowNumber <=3 THEN NULL
ELSE ( SELECT avg(Number)
FROM NumberedRows
WHERE RowNumber < nr.RowNumber
AND RowNumber >= nr.RowNumber - 3
)
END AS MovingAverage
FROM NumberedRows nr
If you do a SET STATISTICS PROFILE ON, you can see the self join has 10k executes on the table spool. The subquery has 10k executes on the filter, aggregate, and other steps.
Want to improve this post? Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted.
Check out some solutions here. I'm sure that you could adapt one of them easily enough.
If you want this to be truly performant, and arn't afraid to dig into a seldom-used area of SQL Server, you should look into writing a custom aggregate function. SQL Server 2005 and 2008 brought CLR integration to the table, including the ability to write user aggregate functions. A custom running total aggregate would be the most efficient way to calculate a running average like this, by far.
Alternatively you can denormalize and store precalculated running values. Described here:
http://sqlblog.com/blogs/alexander_kuznetsov/archive/2009/01/23/denormalizing-to-enforce-business-rules-running-totals.aspx
Performance of selects is as fast as it goes. Of course, modifications are slower.

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