I know its not possible to have a computed column take into consideration its calculations another computed column. I found out the hard ware with the following error:
"is not allowed to be used in another computed-column definition."
So i have the following data columns, which arent neccessarily important, but just so you understand what I am doing (any other columns referenced are standard non computed columns):
HardwareAssetDepreciableValue AS CONVERT(DECIMAL(7,2),HardwareAssetPurchaseValue -
HardwareAssetSalvageValue)
HardwareAssetLifeSpan AS CONVERT(DECIMAL(6,2),DATEDIFF(day,HardwareAssetDateInstalled,
HardwareAssetEndOfLifeDate)) / 365
They are all calculated and work as expected, however what I am having issues with is a rather complicated set of calculations at best, but wondering if anyone can suggest or help with alternatives to resolving the issue of multiple computed columns.
My query is:
HardwareAssetAccumulatedDepreciationValue AS CASE WHEN HardwareAssetDepreciationMethodID
= '1' THEN CONVERT(DECIMAL(7,2),((HardwareAssetDepreciableValue / HardwareAssetLifeSpan)
/ 365)) WHEN HardwareAssetDepreciationMethodID = '2' THEN CONVERT(DECIMAL(7,2),
HardwareAssetAccumulatedDepreciationValue + ((1.5 *(1/HardwareAssetLifeSpan))*
HardwareAssetBookValue)/365) ELSE CONVERT(DECIMAL(7,2),
HardwareAssetAccumulatedDepreciationValue + ((2 *(1/HardwareAssetLifeSpan))
*HardwareAssetBookValue)/365) END
Any help or advice is appreciated!
This error is not allowed to be used in another computed-column definition. occurs when you have used computed column to calculate another column value...
it seems you have below computed column
HardwareAssetDepreciableValue
And then you ,use the same to calculate below computed column
THEN CONVERT(DECIMAL(7,2),((HardwareAssetDepreciableValue / HardwareAssetLifeSpan)
/ 365))
you should not do like that..instead ,you should use base calculation
but wondering if anyone can suggest or help with alternatives to resolving the issue of multiple computed columns.
at present,there are no better alternatives ,one solution i could think of is a view to query the base table and use already existing computed values
A computed column is good for a "one off" IMHO.
For something a tad bit complex, I like to create a scalar user defined function, and wrap the "mini logic" in it.
Here is a simple Northwind example. It doesn't make alot of pratical sense, but demonstrates.
Now, I don't like the below udfExampleUdfTwoDoubleUdfOne idea. But it could work for you.
Its an idea for the arsenal of tools. Which is because you asked for alternate ideas.
Use Northwind
GO
create function dbo.udfExampleUdfOne(#OrderID as int, #ProductID int, #UnitPrice money )
returns int
as
begin
declare #returnValue int = 0
select #returnValue = ISNULL(#OrderID,0) + ISNULL(#ProductID,0) + ISNULL(#UnitPrice,0)
return #returnValue;
end;
GO
create function dbo.udfExampleUdfTwoDoubleUdfOne(#udfOneResult int)
returns int
as
begin
declare #returnValue int = 0
select #returnValue = ISNULL(#udfOneResult,0) * 2
return #returnValue;
end;
GO
SELECT TOP 1000 [OrderID]
,[ProductID]
,[UnitPrice]
,[Quantity]
,[Discount]
, MyValueOne = dbo.udfExampleUdfOne(OrderID , ProductID , UnitPrice)
, MyValueTwoWhichIsActuallyDoubleValueOne = dbo.udfExampleUdfTwoDoubleUdfOne(dbo.udfExampleUdfOne(OrderID , ProductID , UnitPrice))
FROM [Northwind].[dbo].[Order Details]
APPEND
So trying to mimic your example
create function dbo.udfComputeHardwareAssetDepreciableValue(#HardwareAssetPurchaseValue int, #HardwareAssetSalvageValue int )
returns int
as
begin
declare #returnValue int = 0
select #returnValue = ISNULL(#HardwareAssetPurchaseValue,0) - ISNULL(#HardwareAssetSalvageValue,0)
return #returnValue;
end;
create function dbo.udfComputeHardwareAssetLifeSpan(#HardwareAssetDateInstalled int, #HardwareAssetEndOfLifeDate int )
returns int
as
begin
declare #returnValue int = 0
select #returnValue = CONVERT(DECIMAL(6,2),DATEDIFF(day,#HardwareAssetDateInstalled,
#HardwareAssetEndOfLifeDate)) / 365
return #returnValue;
end;
Then write a third UDF that encapsulates your HardwareAssetAccumulatedDepreciationValue IF/THEN/CASE logic.
You ~could~ pass in the computed columns into the new udfComputeHardwareAssetAccumulatedDepreciationValue function as well.
Even if you are new , you should spend a little time struggling with this concept as its a tool in the best to avoid RBAR/CURSORS.
You can get the Northwind db from here:
https://technet.microsoft.com/en-us/library/ms143221(v=sql.105).aspx
Yes, its very old, but simple demos can be created from it.
you can make both of the columns user defined Function , i was looking for it but finally got , the function can access all the columns computed ND NON Computed...
thank you
I have to count the digits after the decimal point in a database hosted by a MS Sql Server (2005 or 2008 does not matter), in order to correct some errors made by users.
I have the same problem on an Oracle database, but there things are less complicated.
Bottom line is on Oracle the select is:
select length( substr(to_char(MY_FIELD), instr(to_char(MY_FILED),'.',1,1)+1, length(to_char(MY_FILED)))) as digits_length
from MY_TABLE
where the filed My_filed is float(38).
On Ms Sql server I try to use:
select LEN(SUBSTRING(CAST(MY_FIELD AS VARCHAR), CHARINDEX('.',CAST(MY_FILED AS VARCHAR),1)+1, LEN(CAST(MY_FIELD AS VARCHAR)))) as digits_length
from MY_TABLE
The problem is that on MS Sql Server, when i cast MY_FIELD as varchar the float number is truncated by only 2 decimals and the count of the digits is wrong.
Can someone give me any hints?
Best regards.
SELECT
LEN(CAST(REVERSE(SUBSTRING(STR(MY_FIELD, 13, 11), CHARINDEX('.', STR(MY_FIELD, 13, 11)) + 1, 20)) AS decimal))
from TABLE
I have received from my friend a very simple solution which is just great. So I will post the workaround in order to help others in the same position as me.
First, make function:
create FUNCTION dbo.countDigits(#A float) RETURNS tinyint AS
BEGIN
declare #R tinyint
IF #A IS NULL
RETURN NULL
set #R = 0
while #A - str(#A, 18 + #R, #r) <> 0
begin
SET #R = #R + 1
end
RETURN #R
END
GO
Second:
select MY_FIELD,
dbo.countDigits(MY_FIELD)
from MY_TABLE
Using the function will get you the exact number of digits after the decimal point.
The first thing is to switch to using CONVERT rather than CAST. The difference is, with CONVERT, you can specify a format code. CAST uses whatever the default format code is:
When expression is float or real, style can be one of the values shown in the following table. Other values are processed as 0.
None of the formats are particularly appealing, but I think the best for you to use would be 2. So it would be:
CONVERT(varchar(25),MY_FIELD,2)
This will, unfortunately, give you the value in scientific notation and always with 16 digits e.g. 1.234567890123456e+000. To get the number of "real" digits, you need to split this number apart, work out the number of digits in the decimal portion, and offset it by the number provided in the exponent.
And, of course, insert usual caveats/warnings about trying to talk about digits when dealing with a number which has a defined binary representation. The number of "digits" of a particular float may vary depending on how it was calculated.
I'm not sure about speed. etc or the elegance of this code. it was for some ad-hoc testing to find the first decimal value . but this code could be changed to loop through all the decimals and find the last time a value was greater than zero easily.
DECLARE #NoOfDecimals int = 0
Declare #ROUNDINGPRECISION numeric(32,16) = -.00001000
select #ROUNDINGPRECISION = ABS(#ROUNDINGPRECISION)
select #ROUNDINGPRECISION = #ROUNDINGPRECISION - floor(#ROUNDINGPRECISION)
while #ROUNDINGPRECISION < 1
Begin
select #NoOfDecimals = #NoOfDecimals +1
select #ROUNDINGPRECISION = #ROUNDINGPRECISION * 10
end;
select #NoOfDecimals
I want to determine if a value is integer (like TryParse in .NET). Unfortunatelly ISNUMERIC does not fit me because I want to parse only integers and not every kind of number. Is there such thing as ISINT or something?
Here is some code to make things clear. If MY_FIELD is not int, this code would fail:
SELECT #MY_VAR = CAST(MY_FIELD AS INT)
FROM MY_TABLE
WHERE MY_OTHER_FIELD = 'MY_FILTER'
Thank you
Here's a blog post describing the creation of an IsInteger UDF.
Basically, it recommends adding '.e0' to the value and using IsNumeric. In this way, anything that already had a decimal point now has two decimal points, causing IsNumeric to be false, and anything already expressed in scientific notation is invalidated by the e0.
In his article Can I convert this string to an integer?, Itzik Ben-Gan provides a solution in pure T-SQL and another that uses the CLR.
Which solution should you choose?
Is the T-SQL or CLR Solution Better? The advantage of using the T-SQL
solution is that you don’t need to go outside the domain of T-SQL
programming. However, the CLR solution has two important advantages:
It's simpler and faster. When I tested both solutions against a table
that had 1,000,000 rows, the CLR solution took two seconds, rather
than seven seconds (for the T-SQL solution), to run on my laptop. So
the next time you need to check whether a given string can be
converted to an integer, you can include the T-SQL or CLR solution
that I provided in this article.
If you only want to maintain T-SQL, then use the pure T-SQL solution. If performance is more important than convenience, then use the CLR solution.
The pure T-SQL Solution is tricky. It combines the built-in ISNUMERIC function with pattern-matching and casting to check if the string represents an int.
SELECT keycol, string, ISNUMERIC(string) AS is_numeric,
CASE
WHEN ISNUMERIC(string) = 0 THEN 0
WHEN string LIKE '%[^-+ 0-9]%' THEN 0
WHEN CAST(string AS NUMERIC(38, 0))
NOT BETWEEN -2147483648. AND 2147483647. THEN 0
ELSE 1
END AS is_int
FROM dbo.T1;
The T-SQL part of the CLR solution is simpler. You call the fn_IsInt function just like you would call ISNUMERIC.
SELECT keycol, string, ISNUMERIC(string) AS is_numeric,
dbo.fn_IsInt(string) AS is_int
FROM dbo.T1;
The C# part is simply a wrapper for the .NET's parsing function Int32.TryParse. This works because the SQL Server int and the .NET Int32 are both 32-bit signed integers.
using System;
using System.Data.SqlTypes;
public partial class UserDefinedFunctions
{
[Microsoft.SqlServer.Server.SqlFunction]
public static SqlBoolean fn_IsInt(SqlString s)
{
if (s.IsNull)
return SqlBoolean.False;
else
{
Int32 i = 0;
return Int32.TryParse(s.Value, out i);
}
}
};
Please read Itzik's article for a full explanation of these code samples.
With sqlserver 2005 and later you can use regex-like character classes with LIKE operator. See here.
To check if a string is a non-negative integer (it is a sequence of decimal digits) you can test that it doesn't contain other characters.
SELECT numstr
FROM table
WHERE numstr NOT LIKE '%[^0-9]%'
Note1: This will return empty strings too.
Note2: Using LIKE '%[0-9]%' will return any string that contains at least a digit.
See fiddle
WHERE IsNumeric(MY_FIELD) = 1 AND CAST(MY_FIELD as VARCHAR(5)) NOT LIKE '%.%'
That is probably the simplest solution. Unless your MY_FIELD contains .00 or something of that sort. In which case, cast it to a float to remove any trailing .00s
Necromancing.
As of SQL-Server 2012+, you can use TRY_CAST, which returns NULL if the cast wasn't successful.
Example:
DECLARE #foo varchar(200)
SET #foo = '0123'
-- SET #foo = '-0123'
-- SET #foo = '+0123'
-- SET #foo = '+-0123'
-- SET #foo = '+-0123'
-- SET #foo = '.123'
-- SET #foo = '1.23'
-- SET #foo = '.'
-- SET #foo = '..'
-- SET #foo = '0123e10'
SELECT CASE WHEN TRY_CAST(#foo AS integer) IS NULL AND #foo IS NOT NULL THEN 0 ELSE 1 END AS isInteger
This is the only really reliable way.
Should you need support for SQL-Server 2008, then fall back to Sam DeHaan's answer:
SELECT CASE WHEN ISNUMERIC(#foo + '.e0') = 1 THEN 1 ELSE 0 END AS isInteger
SQL-Server < 2012 (aka 2008R2) will reach end of (extended) support by 2019-07-09.
At this time, which is very soon, support for < 2012 can be dropped.
I wouldn't use any of the other hacks at this point in time anymore.
Just tell your frugal customers to update - it's been over 10 years since 2008.
See whether the below query will help
SELECT *
FROM MY_TABLE
WHERE CHARINDEX('.',MY_FIELD) = 0 AND CHARINDEX(',',MY_FIELD) = 0
AND ISNUMERIC(MY_FIELD) = 1 AND CONVERT(FLOAT,MY_FIELD) / 2147483647 <= 1
The following is correct for a WHERE clause; to make a function wrap it in CASE WHEN.
ISNUMERIC(table.field) > 0 AND PATINDEX('%[^0123456789]%', table.field) = 0
This work around with IsNumeric function will work:
select * from A where ISNUMERIC(x) =1 and X not like '%.%'
or Use
select * from A where x **not like** '%[^0-9]%'
declare #i numeric(28,5) = 12.0001
if (#i/cast(#i as int) > 1)
begin
select 'this is not int'
end
else
begin
select 'this is int'
end
As of SQL Server 2012, the TRY_CONVERT and TRY_CAST functions were implemented. Thise are vast improvements over the ISNUMERIC solution, which can (and does) give false positives (or negatives). For example if you run the below:
SELECT CONVERT(int,V.S)
FROM (VALUES('1'),
('900'),
('hello'),
('12b'),
('1.1'),
('')) V(S)
WHERE ISNUMERIC(V.S) = 1;
Using TRY_CONVERT (or TRY_CAST) avoids that:
SELECT TRY_CONVERT(int,V.S),
V.S,
ISNUMERIC(V.S)
FROM (VALUES('1'),
('900'),
('hello'),
('12b'),
('1.1'),
('')) V(S)
--WHERE TRY_CONVERT(int,V.S) IS NOT NULL; --To filter to only convertable values
Notice that '1.1' returned NULL, which cause the error before (as a string represtation of a decimal cannot be converted to an int) but also that '' returned 0, even though ISNUMERIC states the value "can't be converted".
Use TRY_CONVERT which is an SQL alternative to TryParse in .NET. IsNumeric() isn’t aware that empty strings are counted as (integer)zero, and that some perfectly valid money symbols, by themselves, are not converted to (money)zero. reference
SELECT #MY_VAR = CASE WHEN TRY_CONVERT(INT,MY_FIELD) IS NOT NULL THEN MY_FIELD
ELSE 0
END
FROM MY_TABLE
WHERE MY_OTHER_FIELD = 'MY_FILTER'
I think that there is something wrong with your database design. I think it is a really bad idea to mix varchar and numbers in one column? What is the reason for that?
Of course you can check if there are any chars other than [0-9], but imagine you have a 1m rows in table and your are checking every row. I think it won't work well.
Anyway if you really want to do it I suggest doing it on the client side.
I have a feeling doing it this way is the work of satan, but as an alternative:
How about a TRY - CATCH?
DECLARE #Converted as INT
DECLARE #IsNumeric BIT
BEGIN TRY
SET #Converted = cast(#ValueToCheck as int)
SET #IsNumeric=1
END TRY
BEGIN CATCH
SET #IsNumeric=0
END CATCH
select IIF(#IsNumeric=1,'Integer','Not integer') as IsInteger
This works, though only in SQL Server 2008 and up.
I tried this script and got the answer
ISNUMERIC(Replace(Replace([enter_your_number],'+','A'),'-','A') + '.0e0')
for example for up question this is answer:
SELECT #MY_VAR = CAST(MY_FIELD AS INT)
FROM MY_TABLE
WHERE MY_OTHER_FIELD = 'MY_FILTER' and ISNUMERIC(Replace(Replace(MY_FIELD,'+','A'),'-','A') + '.0e0') = 1
Why not just do something like:
CASE
WHEN ROUND(MY_FIELD,0)=MY_FIELD THEN CAST(MY_FIELD AS INT)
ELSE MY_FIELD
END
as MY_FIELD2
Sometimes you don't get to design the database, you just have to work with what you are given. In my case it's a database located on a computer that I only have read access to which has been around since 2008.
I need to select from a column in a poorly designed database which is a varchar with numbers 1-100 but sometimes a random string. I used the following to get around it (although I wish I could have re designed the entire database).
SELECT A from TABLE where isnumeric(A)=1
I am not a Pro in SQL but what about checking if it is devideable by 1 ?
For me it does the job.
SELECT *
FROM table
WHERE fieldname % 1 = 0
Use PATINDEX
DECLARE #input VARCHAR(10)='102030.40'
SELECT PATINDEX('%[^0-9]%',RTRIM(LTRIM(#input))) AS IsNumber
reference
http://www.intellectsql.com/post-how-to-check-if-the-input-is-numeric/
Had the same question. I finally used
where ATTRIBUTE != round(ATTRIBUTE)
and it worked for me
WHERE IsNumeric(value + 'e0') = 1 AND CONVERT(FLOAT, value) BETWEEN -2147483648 AND 2147483647
Seeing as this is quite old, but my solution isn't here, i thought to add another possible way to do this:
--This query only returns values with decimals
SELECT ActualCost
FROM TransactionHistory
where cast(ActualCost as int) != ActualCost
--This query only returns values without decimals
SELECT ActualCost
FROM TransactionHistory
where cast(ActualCost as int) = ActualCost
The easy part here is checking if the selected value is the same when cast as an integer.
we can check if its a non integer by
SELECT number2
FROM table
WHERE number2 LIKE '%[^0-9]%' and (( right(number2 ,len(number2)-1) LIKE '%[^0-9]%' and lefT(number2 ,1) <> '-') or ( right(number2 ,len(number2)-1) LIKE '%[^0-9]%' and lefT(number2 ,1) in ( '-','+') ) )
DECLARE #zip_code NCHAR(10)
SET #zip_code = '1239'
IF TRY_PARSE( #zip_code AS INT) / TRY_PARSE( #zip_code AS INT) = 1 PRINT 'integer'
ELSE PRINT 'not integer'
This works fine in SQL Server
SELECT (SELECT ISNUMERIC(2) WHERE ISNUMERIC(2)=1 AND 2 NOT LIKE '%.%')
Case
When (LNSEQNBR / 16384)%1 = 0 then 1
else 0
end
I need to execute a query that is highly dependent on several conditions what need to be checked by analyzing that data in other tables, the base goal is to return the rows from the tables if all of the conditions in the other tables are true, I am fed up with INNER joins LEFT joins and WHERE statement, i need to look up one table, if the returned value is 1, 0 or 4 or a set of values, i need to execute an other statement, and based on the resuts of that i need to execute one last statement which is my final result.
as far as functions are procedures are concerned, i studies the MySQL documentation like hell and all it gives me is this ::
DELIMITER $$
CREATE DEFINER=`root`#`localhost` FUNCTION `SimpleCompare`(n INT, m INT) RETURNS varchar(20) CHARSET latin1
BEGIN
DECLARE s VARCHAR(20);
IF n > m THEN SET s = '>';
ELSEIF n = m THEN SET s = '=';
ELSE SET s = '<';
END IF;
SET s = CONCAT(n, ' ', s, ' ', m);
RETURN s;
END
Now this is so plain, i dont even know where to start, I the "returns varchar(20)" what does it need to be if im expecting it to return a table of 10 rows and not a VARCHAR(20), what do I declare "DECLARE s VARCHAR(20);" as if i want it to be a table not a VARCHAR(20).
the (n > m) after the "IF" how to i replace it with my own query ,
and after I do that, the "THEN SET s = '>'" how do i set s = to the query results ?, this is driving me crazy the syntax is beyond me, and the documentation does not explain anything.
Thanks in advance
To my knowledge, MySQL doesn't support a table valued data type. The use of the function you posted would be:
SELECT simplecompare(yt.n, yt.m) AS eval
FROM YOUR_TABE yt
...which would return:
eval
--------
1 = 1
2 < 3
etc.
SQL is set based, which is different from typical programming (procedural or OO).