Declare a local variable in named calculation expression - sql-server

I would like to create a named calculation field for age, and I want to declare a local variable inside an expression like the following, but it doesn't not work :
DECLARE
#age INT;
#age=DateDiff("yyyy",DATE_NAIS,getdate());
CASE WHEN #age<=10 THEN 1
WHEN #age>10 AND #age<=20 THEN 2
WHEN #age>20 AND #age<=35 THEN 3
ELSE 4
END

Correct, you cannot DECLARE a variable in the context of an expression in a SELECT, like you are trying to do.
You have a few different options, one of which digital.aaron gave in his comments.
Another is to create it as an artificial column in a CTE, and then select from the CTE instead of the table:
WITH cte AS (SELECT *, DateDiff("yyyy",DATE_NAIS,getdate()) AS age FROM MyTable)
SELECT CASE
WHEN age<=10 THEN 1
WHEN age>10 AND age<=20 THEN 2
WHEN age>20 AND age<=35 THEN 3
ELSE 4
END AS SomeColumn
FROM cte

This question is tagged with SSAS, so I'm guessing you're doing this in a cube? The following DAX formula will work as a calculated column in your model for what was described in your post. As stated in the comments DATEDIFF alone will only return the difference between the current year and the year the person was born, which is why YEARFRAC is used to obtain the fraction of a year, then this is rounded down to the nearest integer via the INT function. For example, someone who is 50 years, 364 days old would be considered 50, not 51. Since TRUE() is given as the first argument of the SWITCH function, this will evaluate each condition until a match is found.
PersonAge:=
var Age = INT(YEARFRAC(YourTable[DATE_NAIS], TODAY()))
RETURN
SWITCH
(TRUE(),
Age < 10, 1,
AND(
Age > 10,
Age <= 20), 2,
AND(
Age > 20,
Age <= 35), 3,
4)

Related

Snowflake: Trouble getting numbers to return from a PIVOT function

I am moving a query from SQL Server to Snowflake. Part of the query creates a pivot table. The pivot table part works fine (I have run it in isolation, and it pulls numbers I expect).
However, the following parts of the query rely on the pivot table- and those parts fail. Some of the fields return as a string-type. I believe that the problem is Snowflake is having issues converting string data to numeric data. I have tried CAST, TRY_TO_DOUBLE/NUMBER, but these just pull up 0.
I will put the code down below, and I appreciate any insight as to what I can do!
CREATE OR REPLACE TEMP TABLE ATTR_PIVOT_MONTHLY_RATES AS (
SELECT
Market,
Coverage_Mo,
ZEROIFNULL(TRY_TO_DOUBLE('Starting Membership')) AS Starting_Membership,
ZEROIFNULL(TRY_TO_DOUBLE('Member Adds')) AS Member_Adds,
ZEROIFNULL(TRY_TO_DOUBLE('Member Attrition')) AS Member_Attrition,
((ZEROIFNULL(CAST('Starting Membership' AS FLOAT))
+ ZEROIFNULL(CAST('Member Adds' AS FLOAT))
+ ZEROIFNULL(CAST('Member Attrition' AS FLOAT)))-ZEROIFNULL(CAST('Starting Membership' AS FLOAT)))
/ZEROIFNULL(CAST('Starting Membership' AS FLOAT)) AS "% Change"
FROM
(SELECT * FROM ATTR_PIVOT
WHERE 'Starting Membership' IS NOT NULL) PT)
I realize this is a VERY big question with a lot of moving parts... So my main question is: How can I successfully change the data type to numeric value, so that hopefully the formulas work in the second half of the query?
Thank you so much for reading through it all!
EDITED FOR SHORTENING THE QUERY WITH UNNEEDED SYNTAX
CAST(), TRY_TO_DOUBLE(), TRY_TO_NUMBER(). I have also put the fields (Starting Membership, Member Adds) in single and double quotation marks.
Unless you are quoting your field names in this post just to highlight them for some reason, the way you've written this query would indicate that you are trying to cast a string value to a number.
For example:
ZEROIFNULL(TRY_TO_DOUBLE('Starting Membership'))
This is simply trying to cast a string literal value of Starting Membership to a double. This will always be NULL. And then your ZEROIFNULL() function is turning your NULL into a 0 (zero).
Without seeing the rest of your query that defines the column names, I can't provide you with a correction, but try using field names, not quoted string values, in your query and see if that gives you what you need.
You first mistake is all your single quoted columns names are being treated as strings/text/char
example your inner select:
with ATTR_PIVOT(id, studentname) as (
select * from values
(1, 'student_a'),
(1, 'student_b'),
(1, 'student_c'),
(2, 'student_z'),
(2, 'student_a')
)
SELECT *
FROM ATTR_PIVOT
WHERE 'Starting Membership' IS NOT NULL
there is no "starting membership" column and we get all the rows..
ID
STUDENTNAME
1
student_a
1
student_b
1
student_c
2
student_z
2
student_a
So you need to change 'Starting Membership' -> "Starting Membership" etc,etc,etc
As Mike mentioned, the 0 results is because the TRY_TO_DOUBLE always fails, and thus the null is always turned to zero.
now, with real "string" values, in real named columns:
with ATTR_PIVOT(Market, Coverage_Mo, "Starting Membership", "Member Adds", "Member Attrition") as (
select * from values
(1, 10 ,'student_a', '23', '150' )
)
SELECT
Market,
Coverage_Mo,
ZEROIFNULL(TRY_TO_DOUBLE("Starting Membership")) AS Starting_Membership,
ZEROIFNULL(TRY_TO_DOUBLE("Member Adds")) AS Member_Adds,
ZEROIFNULL(TRY_TO_DOUBLE("Member Attrition")) AS Member_Attrition
FROM ATTR_PIVOT
WHERE "Starting Membership" IS NOT NULL
we get what we would expect:
MARKET
COVERAGE_MO
STARTING_MEMBERSHIP
MEMBER_ADDS
MEMBER_ATTRITION
1
10
0
23
150

Column in SSRS to show value according to the parameter value in SSRS

I have one column in SSRS report which should show the value according to the parameter, if the parameter is selected to Million Euro then it should show the value in Million Euro which means the value should be divided by 10^6,if the parameter is selected as K Euro then the value should be as K Euros which means the value should be divided by 10^3.
I tried to create a dataset where I wrote the SQL query and made a parameter but it didn't worked.
Can anyone give the solution like what should be my dataset query and how should I map it with the parameter.
I used
if #CurrencyConv='MEuro' BEGIN
select 1/Power(10,6) as ProductValue
end
else BEGIN select 1/Power(10,3) as ProductValue
END
And made a parameter where I hardcoded the available values as 'MEuro' and 'KEuro'
And in that column's expression I multiplied the column value with Dataset Value(ProductValue)
Column name is Converted Booking and I have to multiply that column according to the parameter value so if the value is MEuro then it should be [Converted Booking]*1/Power(10,6)
In Sql the below query is working
select [Converted Booking]*1/Power(10,6) from T_GCP_REP
How to apply same thing in SSRS
If you want the final calculated value in you dataset then change your dataset query to
SELECT
*,
CAST([Converted Booking] as float) / CASE WHEN #CurrencyConv = 'MEuro' THEN 1000000 ELSE 1000 END as ConvertedBookingFinal
from T_GCP_REP
OR
If you want to do this purely in SSRS (maybe you cannot change your dataset query?)
The Set the parameter values to 1000 and 1000000 respectively.
Then in the report textbox set the expression to
= Fields.Converted_Booking.Value / Parameters!myParameterName.Value
you can leave the parameter labels as "MEuro" etc you only need to change the value.
If you want the field in your SQL, you can add it using a CASE statement.
SELECT *, 1/Power(10, CASE WHEN #CurrencyConv = 'MEuro' THEN 6 ELSE 3 END) as ProductValue
FROM TABLE
or you could use the new IIF in SQL like SSRS has
SELECT *, 1/Power(10, IIF(#CurrencyConv = 'MEuro', 6, 3)) as ProductValue
FROM TABLE
For an SSRS expression, an IIF statement could also be used:
=1/Power(10, IIF(Parameters!CurrencyConv.Value = 'MEuro', 6, 3))
Though it might be better to use MEuro as the parameter label and have 6 as the value (with KEuro, 3 for the other possible value). Then you could shorten it to:
=1/Power(10, Parameters!CurrencyConv.Value)

Make a variable dynamic enough alter value based on month

Is there any way to have a variable inside a variable loop through 12 numbers every time called? I may just be malnourished in SQL loop logic. Here is the variable I have, as of now I can only get it to hold a static number.
SET #startEnr = (SELECT COUNT(*)
FROM Enrollment
WHERE MONTH(startDate) = 09
AND active = 1
AND endYear = 2020
The value 09 needs to hold 12 values as if #x = 1...12. I've attempted looping this however an error returns stating that the variable can't hold more than one value. Would I need a function?
As commenters have pointed out, the only real array in SQL is a table. I think what you're looking for is something like this:
CREATE TABLE #mthEnroll (mth int, cnt int)
INSERT INTO #mthEnroll (mth, cnt)
SELECT MONTH(startdate), COUNT(*)
FROM Enrollment
WHEREactive = 1
AND endYear = 2020
GROUP BY MONTH(startdate)
DROP TABLE #mthEnroll
You may have to do some tinkering if you have the possibility of months with no entries (e.g., 0 students enrolled in July would NOT have a row), but if it's necessary to get 0's, there are other ways.

Expression to Change Background colour if twice the 10 day average

I've got this expression in a report:
=iif(
SUM(Fields!Amount.Value) >
(
SUM(iif
(
Fields!Date.Value >= DateAdd("d",-10,TODAY())
,Fields!Amount.Value
,CDbl(0)
)) / 10
)*2.0,
"Gold",
"Transparent"
)
It is controlling a table's text box background colour.
I was hoping it would change the cell to gold if the amount in the cell is twice, or more, than the 10 day average for that specific row.
The table shows 10 days of data and the dataset it uses has 60 days of data in it, so 10 day averages should be available.
Is the expression incorrect?
This is what it is currently creating - the two rows that are completely orange are obviously not what I want.
The issue is with the sum you are doing to create your average. It is really only summing the first number it encounters and then dividing by 10 and multiplying by 2. You need to change the scope of your sum to the entire dataset. Here's how I proved this out.
I took the second row of numbers in your table above as my example. Here's my query.
SELECT '1/15/14' AS dt, 1 AS value
UNION
SELECT '1/16/14' AS dt, 7 AS value
UNION
SELECT '1/17/14' AS dt, 5 AS value
UNION
SELECT '1/18/14' AS dt, 6 AS value
UNION
SELECT '1/19/14' AS dt, 4 AS value
UNION
SELECT '1/20/14' AS dt, 5 AS value
UNION
SELECT '1/21/14' AS dt, 5 AS value
UNION
SELECT '1/22/14' AS dt, 5 AS value
UNION
SELECT '1/23/14' AS dt, 6 AS value
UNION
SELECT '1/24/14' AS dt, 6 AS value
I created a tablix with dt in the columns value in the data. If I take your average calculation and put it in a row below, it will return 9.8 for every column.
I first used your fill expression to make sure I got the same results as you. Then I altered it to get the correct answer:
=iif(Sum(Fields!value.Value) >
(Sum(iif(Fields!dt.Value >= Dateadd("d",-10, today()), Fields!value.Value, CDbl(0)), "DataSet1")/10) * 2,
"Gold","White")
With the data I had, none of the cells should turn gold, and that is the result I got. If I change the value for 1/15 to 20 and then preview my table, that cell turns gold because 69/10*2 = 13.8 and 20 > 13.8.

How do I generate a random number for each row in a T-SQL select?

I need a different random number for each row in my table. The following seemingly obvious code uses the same random value for each row.
SELECT table_name, RAND() magic_number
FROM information_schema.tables
I'd like to get an INT or a FLOAT out of this. The rest of the story is I'm going to use this random number to create a random date offset from a known date, e.g. 1-14 days offset from a start date.
This is for Microsoft SQL Server 2000.
Take a look at SQL Server - Set based random numbers which has a very detailed explanation.
To summarize, the following code generates a random number between 0 and 13 inclusive with a uniform distribution:
ABS(CHECKSUM(NewId())) % 14
To change your range, just change the number at the end of the expression. Be extra careful if you need a range that includes both positive and negative numbers. If you do it wrong, it's possible to double-count the number 0.
A small warning for the math nuts in the room: there is a very slight bias in this code. CHECKSUM() results in numbers that are uniform across the entire range of the sql Int datatype, or at least as near so as my (the editor) testing can show. However, there will be some bias when CHECKSUM() produces a number at the very top end of that range. Any time you get a number between the maximum possible integer and the last exact multiple of the size of your desired range (14 in this case) before that maximum integer, those results are favored over the remaining portion of your range that cannot be produced from that last multiple of 14.
As an example, imagine the entire range of the Int type is only 19. 19 is the largest possible integer you can hold. When CHECKSUM() results in 14-19, these correspond to results 0-5. Those numbers would be heavily favored over 6-13, because CHECKSUM() is twice as likely to generate them. It's easier to demonstrate this visually. Below is the entire possible set of results for our imaginary integer range:
Checksum Integer: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Range Result: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 0 1 2 3 4 5
You can see here that there are more chances to produce some numbers than others: bias. Thankfully, the actual range of the Int type is much larger... so much so that in most cases the bias is nearly undetectable. However, it is something to be aware of if you ever find yourself doing this for serious security code.
When called multiple times in a single batch, rand() returns the same number.
I'd suggest using convert(varbinary,newid()) as the seed argument:
SELECT table_name, 1.0 + floor(14 * RAND(convert(varbinary, newid()))) magic_number
FROM information_schema.tables
newid() is guaranteed to return a different value each time it's called, even within the same batch, so using it as a seed will prompt rand() to give a different value each time.
Edited to get a random whole number from 1 to 14.
RAND(CHECKSUM(NEWID()))
The above will generate a (pseudo-) random number between 0 and 1, exclusive. If used in a select, because the seed value changes for each row, it will generate a new random number for each row (it is not guaranteed to generate a unique number per row however).
Example when combined with an upper limit of 10 (produces numbers 1 - 10):
CAST(RAND(CHECKSUM(NEWID())) * 10 as INT) + 1
Transact-SQL Documentation:
CAST(): https://learn.microsoft.com/en-us/sql/t-sql/functions/cast-and-convert-transact-sql
RAND(): http://msdn.microsoft.com/en-us/library/ms177610.aspx
CHECKSUM(): http://msdn.microsoft.com/en-us/library/ms189788.aspx
NEWID(): https://learn.microsoft.com/en-us/sql/t-sql/functions/newid-transact-sql
Random number generation between 1000 and 9999 inclusive:
FLOOR(RAND(CHECKSUM(NEWID()))*(9999-1000+1)+1000)
"+1" - to include upper bound values(9999 for previous example)
Answering the old question, but this answer has not been provided previously, and hopefully this will be useful for someone finding this results through a search engine.
With SQL Server 2008, a new function has been introduced, CRYPT_GEN_RANDOM(8), which uses CryptoAPI to produce a cryptographically strong random number, returned as VARBINARY(8000). Here's the documentation page: https://learn.microsoft.com/en-us/sql/t-sql/functions/crypt-gen-random-transact-sql
So to get a random number, you can simply call the function and cast it to the necessary type:
select CAST(CRYPT_GEN_RANDOM(8) AS bigint)
or to get a float between -1 and +1, you could do something like this:
select CAST(CRYPT_GEN_RANDOM(8) AS bigint) % 1000000000 / 1000000000.0
The Rand() function will generate the same random number, if used in a table SELECT query. Same applies if you use a seed to the Rand function. An alternative way to do it, is using this:
SELECT ABS(CAST(CAST(NEWID() AS VARBINARY) AS INT)) AS [RandomNumber]
Got the information from here, which explains the problem very well.
Do you have an integer value in each row that you could pass as a seed to the RAND function?
To get an integer between 1 and 14 I believe this would work:
FLOOR( RAND(<yourseed>) * 14) + 1
If you need to preserve your seed so that it generates the "same" random data every time, you can do the following:
1. Create a view that returns select rand()
if object_id('cr_sample_randView') is not null
begin
drop view cr_sample_randView
end
go
create view cr_sample_randView
as
select rand() as random_number
go
2. Create a UDF that selects the value from the view.
if object_id('cr_sample_fnPerRowRand') is not null
begin
drop function cr_sample_fnPerRowRand
end
go
create function cr_sample_fnPerRowRand()
returns float
as
begin
declare #returnValue float
select #returnValue = random_number from cr_sample_randView
return #returnValue
end
go
3. Before selecting your data, seed the rand() function, and then use the UDF in your select statement.
select rand(200); -- see the rand() function
with cte(id) as
(select row_number() over(order by object_id) from sys.all_objects)
select
id,
dbo.cr_sample_fnPerRowRand()
from cte
where id <= 1000 -- limit the results to 1000 random numbers
select round(rand(checksum(newid()))*(10)+20,2)
Here the random number will come in between 20 and 30.
round will give two decimal place maximum.
If you want negative numbers you can do it with
select round(rand(checksum(newid()))*(10)-60,2)
Then the min value will be -60 and max will be -50.
try using a seed value in the RAND(seedInt). RAND() will only execute once per statement that is why you see the same number each time.
If you don't need it to be an integer, but any random unique identifier, you can use newid()
SELECT table_name, newid() magic_number
FROM information_schema.tables
You would need to call RAND() for each row. Here is a good example
https://web.archive.org/web/20090216200320/http://dotnet.org.za/calmyourself/archive/2007/04/13/sql-rand-trap-same-value-per-row.aspx
The problem I sometimes have with the selected "Answer" is that the distribution isn't always even. If you need a very even distribution of random 1 - 14 among lots of rows, you can do something like this (my database has 511 tables, so this works. If you have less rows than you do random number span, this does not work well):
SELECT table_name, ntile(14) over(order by newId()) randomNumber
FROM information_schema.tables
This kind of does the opposite of normal random solutions in the sense that it keeps the numbers sequenced and randomizes the other column.
Remember, I have 511 tables in my database (which is pertinent only b/c we're selecting from the information_schema). If I take the previous query and put it into a temp table #X, and then run this query on the resulting data:
select randomNumber, count(*) ct from #X
group by randomNumber
I get this result, showing me that my random number is VERY evenly distributed among the many rows:
It's as easy as:
DECLARE #rv FLOAT;
SELECT #rv = rand();
And this will put a random number between 0-99 into a table:
CREATE TABLE R
(
Number int
)
DECLARE #rv FLOAT;
SELECT #rv = rand();
INSERT INTO dbo.R
(Number)
values((#rv * 100));
SELECT * FROM R
select ABS(CAST(CAST(NEWID() AS VARBINARY) AS INT)) as [Randomizer]
has always worked for me
Use newid()
select newid()
or possibly this
select binary_checksum(newid())
If you want to generate a random number between 1 and 14 inclusive.
SELECT CONVERT(int, RAND() * (14 - 1) + 1)
OR
SELECT ABS(CHECKSUM(NewId())) % (14 -1) + 1
DROP VIEW IF EXISTS vwGetNewNumber;
GO
Create View vwGetNewNumber
as
Select CAST(RAND(CHECKSUM(NEWID())) * 62 as INT) + 1 as NextID,
'abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'as alpha_num;
---------------CTDE_GENERATE_PUBLIC_KEY -----------------
DROP FUNCTION IF EXISTS CTDE_GENERATE_PUBLIC_KEY;
GO
create function CTDE_GENERATE_PUBLIC_KEY()
RETURNS NVARCHAR(32)
AS
BEGIN
DECLARE #private_key NVARCHAR(32);
set #private_key = dbo.CTDE_GENERATE_32_BIT_KEY();
return #private_key;
END;
go
---------------CTDE_GENERATE_32_BIT_KEY -----------------
DROP FUNCTION IF EXISTS CTDE_GENERATE_32_BIT_KEY;
GO
CREATE function CTDE_GENERATE_32_BIT_KEY()
RETURNS NVARCHAR(32)
AS
BEGIN
DECLARE #public_key NVARCHAR(32);
DECLARE #alpha_num NVARCHAR(62);
DECLARE #start_index INT = 0;
DECLARE #i INT = 0;
select top 1 #alpha_num = alpha_num from vwGetNewNumber;
WHILE #i < 32
BEGIN
select top 1 #start_index = NextID from vwGetNewNumber;
set #public_key = concat (substring(#alpha_num,#start_index,1),#public_key);
set #i = #i + 1;
END;
return #public_key;
END;
select dbo.CTDE_GENERATE_PUBLIC_KEY() public_key;
Update my_table set my_field = CEILING((RAND(CAST(NEWID() AS varbinary)) * 10))
Number between 1 and 10.
Try this:
SELECT RAND(convert(varbinary, newid()))*(b-a)+a magic_number
Where a is the lower number and b is the upper number
If you need a specific number of random number you can use recursive CTE:
;WITH A AS (
SELECT 1 X, RAND() R
UNION ALL
SELECT X + 1, RAND(R*100000) --Change the seed
FROM A
WHERE X < 1000 --How many random numbers you need
)
SELECT
X
, RAND_BETWEEN_1_AND_14 = FLOOR(R * 14 + 1)
FROM A
OPTION (MAXRECURSION 0) --If you need more than 100 numbers

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