Assigning DISTINCT value to a variable in SQL - sql-server

I have a dataset with one of the columns as Transaction_Date in which date varies from the year 2005 to 2018.
I need to assign a distinct year to a variable, later on, I will be using the same variable in SQL Pivot.
-- variable declaration
DECLARE #PCOL VARCHAR(20);
-- assigning values to the variable
SELECT #PCOL += (QUOTENAME (X.TD) + ',')
FROM
(
SELECT DISTINCT YEAR(TRANSACTION_DATE) AS TD
FROM TRANSACTION_INFO
) AS X;
-- Check the result
PRINT #PCOL
It is not resulting me the output as expected. Please suggest.

You need FOR XML PATH() clause :
SELECT #PCOL = STUFF( (SELECT DISTINCT ', '+ QUOTENAME(CAST(YEAR(TRANSACTION_DATE) AS VARCHAR(255)))
FROM TRANSACTION_INFO
FOR XML PATH('')
), 1, 1, ''
)

You're getting NULL because you didn't pre-set your variable to an empty string before you used the += operator.
Since NULL + 'some value' = NULL, your variable never gets changed from NULL to something else.

It looks like this is what you're attempting to do...
IF OBJECT_ID('tempdb..#TRANSACTION_INFO', 'U') IS NOT NULL
BEGIN DROP TABLE #TRANSACTION_INFO; END;
CREATE TABLE #TRANSACTION_INFO (
TRANSACTION_DATE DATE
);
INSERT #TRANSACTION_INFO (TRANSACTION_DATE) VALUES
('20130101'),('20130101'),('20140101'),
('20140102'),('20150102'),('20150102'),
('20160103'),('20160103'),('20170104'),
('20170104'),('20180105'),('20180105');
--================================================
DECLARE #POL VARCHAR(200) = '';
SELECT
#POL = CONCAT(#POL, ',', x.TD)
FROM (
SELECT DISTINCT
TD = YEAR(ti.TRANSACTION_DATE)
FROM
#TRANSACTION_INFO ti
) x;
SET #POL = STUFF(#POL, 1, 1, '');
PRINT(#POL);
Result:
2013,2014,2015,2016,2017,2018

Related

How to pass string with single quotations to in()

I am working on a query that I need to modify so that a string is passed to in(). The view table is being used by some other view table and ultimately by a stored procedure. The string values must be in ' '.
select region, county, name
from vw_main
where state - 'MD'
and building_id in ('101', '102') -- pass the string into in()
The values for the building_id will be entered at the stored procedure level upon its execution.
Please check below scripts which will give you answer.
Way 1: Split CSV value using XML and directly use select query in where condition
DECLARE #StrBuildingIDs VARCHAR(1000)
SET #StrBuildingIDs = '101,102'
SELECT
vm.region,
vm.county,
vm.name
FROM vw_main vm
WHERE vm.state = 'MD'
AND vm.building_id IN
(
SELECT
l.value('.','VARCHAR(20)') AS Building_Id
FROM
(
SELECT CAST('<a>' + REPLACE(#StrBuildingIDs,',','</a><a>') + '</a>') AS BuildIDXML
) x
CROSS APPLY x.BuildIDXML.nodes('a') Split(l)
)
Way 2: Split CSV value using XML, Create Variable Table and use that in where condition
DECLARE #StrBuildingIDs VARCHAR(1000)
SET #StrBuildingIDs = '101,102'
DECLARE #TblBuildingID TABLE(BuildingId INT)
INSERT INTO #TblBuildingID(BuildingId)
SELECT
l.value('.','VARCHAR(20)') AS Building_Id
FROM
(
SELECT CAST('<a>' + REPLACE(#StrBuildingIDs,',','</a><a>') + '</a>') AS BuildIDXML
) x
CROSS APPLY x.BuildIDXML.nodes('a') Split(l)
SELECT
vm.region,
vm.county,
vm.name
FROM vw_main AS vm
WHERE vm.state = 'MD'
AND vm.building_id IN
(
SELECT
BuildingId
FROM #TblBuildingID
)
Way 3: Split CSV value using XML, Create Variable Table and use that in INNER JOIN
Assuming the input string is not end-user input, you can do this. That is, derived or pulled from another table or other controlled source.
DECLARE #in nvarchar(some length) = N'''a'',''b'',''c'''
declare #stmt nvarchar(4000) = N'
select region, county, name
from vw_main
where state = ''MD''
and building_id in ({instr})'
set #stmt = replace(#stmt, N'{instr}', #instr)
exec sp_executesql #stmt=#stmt;
If the input is from an end-user, this is safer:
declare # table (a int, b char)
insert into #(a, b) values (1,'A'), (2, 'B')
declare #str varchar(50) = 'A,B'
select t.* from # t
join (select * from string_split(#str, ',')) s(b)
on t.b = s.b
You may like it better anyway, since there's no dynamic sql involved. However you must be running SQL Server 2016 or higher.

TSQL: How insert separator between each character in a string

I have a string like this:
Apple
I want to include a separator after each character so the end result will turn out like this:
A,p,p,l,e
In C#, we have one liner method to achieve the above with Regex.Replace('Apple', ".{1}", "$0,");
I can only think of looping each character with charindex to append the separator but seems a little complicated. Is there any elegant way and simpler way to achieve this?
Thanks HABO for the suggestions. I'm able to generate the result that I want using the code but takes a little bit of time to really understand how the code work.
After some searching, I manage to found one useful article to insert empty spaces between each character and it's easier for me to understand.
I modify the code a little to define and include desire separator instead of fixing it to space as the separator:
DECLARE #pos INT = 2 -- location where we want first space
DECLARE #result VARCHAR(100) = 'Apple'
DECLARE #separator nvarchar(5) = ','
WHILE #pos < LEN(#result)+1
BEGIN
SET #result = STUFF(#result, #pos, 0, #separator);
SET #pos = #pos+2;
END
select #result; -- Output: A,p,p,l,e
Reference
In following SQL scripts, I get each character using SUBSTRING() function using with a number table (basically I used spt_values view here for simplicity) and then I concatenate them via two different methods, you can choose one
If you are using SQL Server 2017, we have a new SQL string aggregation function
First script uses string_agg function
declare #str nvarchar(max) = 'Apple'
SELECT
string_agg( substring(#str,number,1) , ',') Within Group (Order By number)
FROM master..spt_values n
WHERE
Type = 'P' and
Number between 1 and len(#str)
If you are working with a previous version, you can use string concatenation using FOR XML Path and SQL Stuff function as follows
declare #str nvarchar(max) = 'Apple'
; with cte as (
SELECT
number,
substring(#str,number,1) as L
FROM master..spt_values n
WHERE
Type = 'P' and
Number between 1 and len(#str)
)
SELECT
STUFF(
(
SELECT
',' + L
FROM cte
order by number
FOR XML PATH('')
), 1, 1, ''
)
Both solution yields the same result, I hope it helps
If you have SQL Server 2017 and a copy of ngrams8k it's ultra simple:
declare #word varchar(100) = 'apple';
select newString = string_agg(token, ',') within group (order by position)
from dbo.ngrams8k(#word,1);
For pre-2017 systems it's almost as simple:
declare #word varchar(100) = 'apple';
select newstring =
( select token + case len(#word)+1-position when 1 then '' else ',' end
from dbo.ngrams8k(#word,1)
order by position
for xml path(''))
One ugly way to do it is to split the string into characters, ideally using a numbers table, and reassemble it with the desired separator.
A less efficient implementation uses recursion in a CTE to split the characters and insert the separator between pairs of characters as it goes:
declare #Sample as VarChar(20) = 'Apple';
declare #Separator as Char = ',';
with Characters as (
select 1 as Position, Substring( #Sample, 1, 1 ) as Character
union all
select Position + 1,
case when Position & 1 = 1 then #Separator else Substring( #Sample, Position / 2 + 1, 1 ) end
from Characters
where Position < 2 * Len( #Sample ) - 1 )
select Stuff( ( select Character + '' from Characters order by Position for XML Path( '' ) ), 1, 0, '' ) as Result;
You can replace the select Stuff... line with select * from Characters; to see what's going on.
Try this
declare #var varchar(50) ='Apple'
;WITH CTE
AS
(
SELECT
SeqNo = 1,
MyStr = #var,
OpStr = CAST('' AS VARCHAR(50))
UNION ALL
SELECT
SeqNo = SeqNo+1,
MyStr = MyStR,
OpStr = CAST(ISNULL(OpStr,'')+SUBSTRING(MyStR,SeqNo,1)+',' AS VARCHAR(50))
FROM CTE
WHERE SeqNo <= LEN(#var)
)
SELECT
OpStr = LEFT(OpStr,LEN(OpStr)-1)
FROM CTE
WHERE SeqNo = LEN(#Var)+1

Multiple rows to single row in Azure Data Warehouse

As Azure DW is not supporting FOR XML and SELECT variable assignment, is there any other way to convert multiple rows into single row except using CURSOR?
I didn't found any direct method however the below code is working for me.
DECLARE #intColumnCount INT,
#intProcessCount INT,
#varColList VARCHAR(max)
SET #varColList = ''
IF Object_id('tempdb.dbo.#tempColumnNames') IS NOT NULL
BEGIN
DROP TABLE #tempcolumnnames;
END
CREATE TABLE #tempcolumnnames
(
intid INT,
varcolumnnames VARCHAR(256)
)
INSERT INTO #tempcolumnnames
SELECT Row_number()
OVER (
ORDER BY NAME),
NAME
FROM sys.tables
SET #intProcessCount = 1
SET #intColumnCount = (SELECT Count(*)
FROM #tempcolumnnames)
WHILE ( #intProcessCount <= #intColumnCount )
BEGIN
SET #varColList = #varColList + ', '
+ (SELECT varcolumnnames
FROM #tempcolumnnames
WHERE intid = #intProcessCount)
SET #intProcessCount +=1
END
SELECT Stuff(#varColList, 1, 2, '')
Hope this helps someone.

SQL Server : Select without some word

I have a procedure like this;
SET #Oldname = (SELECT name
FROM [Marketing].[dbo].[_Users]
WHERE ID = #MID);
Everything is okay but some members got xxx, xxx_A1,xxx_A2,xxx_A3, while selecting these members I want to select without _A1 , _A2 , A_30
How can I select it?
Try reversing string, find first index of _ and apply substring:
DECLARE #s NVARCHAR(MAX) = 'John_Smith_234'
DECLARE #t TABLE ( Name NVARCHAR(50) )
INSERT INTO #t
VALUES ( 'John_Smith_234' ),
( 'Michael_Jordan' ),
( 'Honore_De_Balzak_234' )
SELECT SUBSTRING(Name, 1, LEN(Name) - CHARINDEX('_', REVERSE(Name))) AS Name
FROM #t
Output:
Name
John_Smith
Michael
Honore_De_Balzak
try this
select left(name, len(name)-charindex('_', reverse(name))) name
from whatever
Assure that you add a '%' sign to your #MID Variable, looking like 'xxx%'
Than SELECT with LIKE instead of = :
SET #Oldname = (SELECT name From [Marketing].[dbo].[_Users] Where ID LIKE #MID);
I think you may also add the '%' sign in qour query (haven't tried):
SET #Oldname = (SELECT name From [Marketing].[dbo].[_Users] Where ID LIKE #MID+'%');

SQL Server 2005 - column names based on variable passed in pivot query

I have following query which takes 2 parameters.
YearNumber
MonthNumber
In my pivot query, I am trying to select columns based on #Year_Rtl variable. I need to select data for the year passed, last year and last last year. Since the data being displayed on UI is table format divided by #Year_Rtl, I decided to write a pivot query for that as below.
In the query, it works fine if I hard code [#Year_Rtl], [#Year_Rtl - 1], [#Year_Rtl - 2] to [2012], [2011], [2010]. But since the year passed can be anything, I want columns to be named dynamically.
DECLARE #Month_Rtl int
DECLARE #Year_Rtl int
SET #Year_Rtl = 2012
SET #Month_Rtl = 1
SELECT
'Data 1', [#Year_Rtl], [#Year_Rtl - 1], [#Year_Rtl - 2]
FROM
(SELECT [Yr_No], Qty
FROM dbo.Table1 t
WHERE (t.Col1 = 10) AND
(t.Col2 = '673') AND
((t.Mth_No = #Month_Rtl AND t.Yr_No = #Year_Rtl) OR
(t.Mth_No = 12 AND t.Yr_No IN (#Year_Rtl - 1, #Year_Rtl - 2)))
) p PIVOT (SUM(Qty)
FOR [Yr_No] IN ([#Year_Rtl], [#Year_Rtl-1], [#Year_Rtl-2])
) AS pvt
Above query throws following errors:
Error converting data type nvarchar to smallint.
The incorrect value "#Year_Rtl" is supplied in the PIVOT operator.
Invalid column name '#Year_Rtl - 1'.
Invalid column name '#Year_Rtl - 2'.
Since you can use dynamic SQL, I'd go with a macro-replacement approach. You're identifying areas of the query that must be dynamically replaced with placeholders (e.g. $$Year_Rtl) and then calculating their replacement values below. I find that it keeps the SQL statement easy to follow.
DECLARE #SQL NVarChar(2000);
SELECT #SQL = N'
SELECT
''Data 1'', [$$Year_Rtl], [$$Year_RtlM1], [$$Year_RtlM2]
FROM
(SELECT [Yr_No], Qty
FROM dbo.Table1 t
WHERE (t.Col1 = 10) AND
(t.Col2 = ''673'') AND
((t.Mth_No = $$Month_Rtl AND t.Yr_No = $$Year_Rtl) OR
(t.Mth_No = 12 AND t.Yr_No IN ($$Year_RtlM1, $$Year_RtlM2)))
) p PIVOT (SUM(Qty)
FOR [Yr_No] IN ([$$Year_Rtl], [$$Year_RtlM1], [$$Year_RtlM2])
) AS pvt';
SELECT #SQL = REPLACE(#SQL, '$$Year_RtlM2', #Year_Rtl - 2);
SELECT #SQL = REPLACE(#SQL, '$$Year_RtlM1', #Year_Rtl - 1);
SELECT #SQL = REPLACE(#SQL, '$$Year_Rtl', #Year_Rtl);
SELECT #SQL = REPLACE(#SQL, '$$Month_Rtl', #Month_Rtl);
PRINT #SQL;
-- Uncomment the next line to allow the built query to execute...
--EXECUTE sp_ExecuteSQL #SQL;
Since consuming code will also have to be flaky under this scheme (e.g. selecting columns based on "position" rather than name) - why not normalize the columns by performing a DATEDIFF(year,Yr_No,#Year_Rtl), and work from there? Those columns will always be 0, -1 and -2...
You need to look into Dynamic SQL Pivoting.
I recommend reading Itzik Ben-Gan's T-SQL Fundamentals where he goes over how to do this.
Alternatively try this article if you don't want to buy the book.
Maybe this will help:
First getting the columns with a tally function like this:
DECLARE #Month_Rtl int,
#Year_Rtl int,
#Year_Rtl_Start INT,
#cols VARCHAR(MAX),
#values VARCHAR(MAX)
SET #Year_Rtl = 2012
SET #Month_Rtl = 1
SET #Year_Rtl_Start=2009
;WITH Years ( n ) AS (
SELECT #Year_Rtl_Start UNION ALL
SELECT 1 + n FROM Years WHERE n < #Year_Rtl )
SELECT
#cols = COALESCE(#cols + ','+QUOTENAME(n),
QUOTENAME(n)),
#values = COALESCE(#values + ','+CAST(n AS VARCHAR(100)),
CAST(n AS VARCHAR(100)))
FROM
Years
ORDER BY n DESC
The variable #cols contains the columns that is in the pivot and the variable #values contains the years for the IN. The #Year_Rtl is the end year and the #Year_Rtl_Start is the start for you range.
Then declaring and executing the dynamic pivot like this:
DECLARE #query NVARCHAR(4000)=
N'SELECT
''Data 1'', '+#cols+'
FROM
(
SELECT
[Yr_No], Qty
FROM
dbo.Table1 t
WHERE
t.Col1 = 10
AND t.Col2 = ''673''
AND
(
(
t.Mth_No = '+CAST(#Month_Rtl AS VARCHAR(10))+'
AND t.Yr_No = '+CAST(#Year_Rtl AS VARCHAR(10))+'
)
OR
(
t.Mth_No = 12
AND t.Yr_No IN ('+#values+'))
)
) p
PIVOT
(
SUM(Qty)
FOR [Yr_No] IN ('+#cols+')
) AS pvt'
EXECUTE(#query)

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