ISNUMERIC

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ISNUMERIC

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March 5, 2013 at 8:18 pm

#271165

Comments posted to this topic are about the item ISNUMERIC
March 6, 2013 at 4:43 am

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happycat59 One Orange Chip Points: 29389 More actions · Answer 1

Mmm, why have "ISNUMERIC" as the heading for this question ? This question is not really about the ISNUMERIC function. How about getting the heading to match what the question is really about instead of deliberately trying to mislead ?

This question is about the default length used for the VARCHAR data type. I am expecting a variation on this question to pop up soon where the answer is VARCHAR (30).

Lokesh Vij SSChampion Points: 10836 More actions · Answer 2

happycat59 (3/5/2013)
Mmm, why have "ISNUMERIC" as the heading for this question ? This question is not really about the ISNUMERIC function. How about getting the heading to match what the question is really about instead of deliberately trying to mislead ?
This question is about the default length used for the VARCHAR data type. I am expecting a variation on this question to pop up soon where the answer is VARCHAR (30).

+1 🙂

Well this question is about ISNUMERIC and VARCHAR both. I realized the VARCHAR gotcha and marked the correct answer.

~ Lokesh Vij

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demonfox SSCertifiable Points: 6289 More actions · Answer 3

Lokesh Vij (3/5/2013)
happycat59 (3/5/2013)
Mmm, why have "ISNUMERIC" as the heading for this question ? This question is not really about the ISNUMERIC function. How about getting the heading to match what the question is really about instead of deliberately trying to mislead ?
This question is about the default length used for the VARCHAR data type. I am expecting a variation on this question to pop up soon where the answer is VARCHAR (30).
+1 🙂
Well this question is about ISNUMERIC and VARCHAR both. I realized the VARCHAR gotcha and marked the correct answer.

well, in a way it is true .. varchar does store only "3"; the first character ..

and ISNumeric does evaluate the string "3" as numeric .. I look at heading to get extra information , but, here straightforward question ..

nice and simple ...

~ demonfox
___________________________________________________________________
Wondering what I would do next , when I am done with this one :ermm:

Vinay Kumar SSCertifiable Points: 6099 More actions · Answer 4

demonfox (3/5/2013)
Lokesh Vij (3/5/2013)
happycat59 (3/5/2013)
Mmm, why have "ISNUMERIC" as the heading for this question ? This question is not really about the ISNUMERIC function. How about getting the heading to match what the question is really about instead of deliberately trying to mislead ?
This question is about the default length used for the VARCHAR data type. I am expecting a variation on this question to pop up soon where the answer is VARCHAR (30).
+1 🙂
Well this question is about ISNUMERIC and VARCHAR both. I realized the VARCHAR gotcha and marked the correct answer.
well, in a way it is true .. varchar does store only "3"; the first character ..
and ISNumeric does evaluate the string "3" as numeric .. I look at heading to get extra information , but, here straightforward question ..
nice and simple ...

+1

Good start of day. 🙂

Thanks
Vinay Kumar
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Keep Learning - Keep Growing !!!

kapil_kk SSC-Insane Points: 21316 More actions · Answer 5

good basic question to start the day....

In first line I saw that its only varchar to length would be 1 only and 3 is present in text so quickly mark the answer as IS Numeric 😛

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http://www.sqlservercentral.com/articles/Best+Practices/61537/

demonfox SSCertifiable Points: 6289 More actions · Answer 6

happycat59 (3/5/2013)
Mmm, why have "ISNUMERIC" as the heading for this question ? This question is not really about the ISNUMERIC function. How about getting the heading to match what the question is really about instead of deliberately trying to mislead ?

a litle modification in the question and a missing reference .. and it would go for the header 😀

DECLARE @vchrIsNumeric CHAR(2)

SET @vchrIsNumeric='3 NAME'

IF ISNUMERIC(@vchrIsNumeric)=1

SELECT 'Is Numeric'

ELSE

SELECT 'Is not Numeric'

output would be the same ..(might put a dot for a second :-P)

and here is the missing reference on IS_Numeric :

http://msdn.microsoft.com/en-gb/library/ms186272.aspx

Edit :

This question is about the default length used for the VARCHAR data type. I am expecting a variation on this question to pop up soon where the answer is VARCHAR (30).

yes.. It might :hehe:

as mentioned in msdn :

When n is not specified in a data definition or variable declaration statement, the default length is 1. When n is not specified when using the CAST and CONVERT functions, the default length is 30.

~ demonfox
___________________________________________________________________
Wondering what I would do next , when I am done with this one :ermm:

Raghavendra Mudugal SSChampion Points: 10658 More actions · Answer 7

well....i did it again......

knowing the declaration without the size will default to 1 and at the time of cast/convert it defaults to 30.... and... me being dumbest of all the time i mentally switched the answers and considered 30 as the default to the variable with no size... thinking "is not numeric" is a straight and sweet deal...

...

..

.

(one second later) after clicking the submit the button

.

#facepalm

(sorry) good question by the way; thank you for posting, remembrance of the defaults is another key point in the level of basic. thank you.

ww; Raghu
--
The first and the hardest SQL statement I have wrote- "select * from customers" - and I was happy and felt smart.

Dineshbabu Hall of Fame Points: 3220 More actions · Answer 8

I read the question very carelessly. I didn't notice that variable declared without specifying length.

--
Dineshbabu
Desire to learn new things..

DugyC Hall of Fame Points: 3804 More actions · Answer 9

Don't really pay attention to the heading as it can often be misleading and just focus entirely on the detail of the question.

I like these "gotcha" bug style questions, little reminders of what's waiting in SQL to catch the unwary LOL!

Good nice question with a quick answer. Great job.

Thanks 😀

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db4breakfast Ten Centuries Points: 1097 More actions · Answer 10

haha. this not really about IsNumeric(). these type of questions are fun to solve. 😀

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amit_adarsh Ten Centuries Points: 1273 More actions · Answer 11

Nice question to check the attentiveness

as well as to expalin the default behaviour of Varchar data type 😎

TomThomson SSC Guru Points: 104773 More actions · Answer 12

Nice question, but I don't much like the heading. Fortunately I've learnt not to pay much attention to QotD headings.

Tom

Hugo Kornelis SSC Guru Points: 64790 More actions · Answer 13

L' Eomot Inversé (3/6/2013)
Nice question, but I don't much like the heading. Fortunately I've learnt not to pay much attention to QotD headings.

I never look at the headings either, so this didn't bother me.

And while I understand the objections raised, I also think that this adds a nice touch of realism. If a junior on my team made this mistake and came to me after not beiing able to figure it out, they would probably also tell me that they have a problem with ISNUMERIC.

Hugo Kornelis, SQL Server/Data Platform MVP (2006-2016)
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