I have a TBV function. And that function getting couple of input parameters.
CREATE FUNCTION [dbo].[fn]
(
#id NVARCHAR(50),
...
...
)
For example i want to check that #id is not null and is not whitespace.
I was tinking to do like this
SELECT * FROM [FN_Table]() WHERE
COALESCE(#Id,'') !='' AND NULLIF(#id,'') !=null AND #Id=Id
But this is a tedious way i am sure that there would be more elegant and effective way i just newbbe in SQL and do not know best practices.
If you want id to be not null or white space, you can use ltrim():
where ltrim(#id) <> ''
This does the NULL check as well, implicitly.
I'm not sure why you have a comparison to zero. Based on your question this is not necessary. If you are passing in numbers, you should not be using a string type.
Try this, Check with ISNULL and then Get BlankSpace Character Index
SELECT
CASE WHEN ISNULL(#ID,'')='' THEN 1
WHEN CHARINDEX(' ',#ID) >0 THEN 1
ELSE 0
END
Related
I have seen several similar questions but none cover what I need. I need to put another THEN statement after the first one. My column contains int's. When it returns NULL I need it to display a blank space, but when I try the below code, I just get '0'.
CASE
WHEN Column1 IS NULL
THEN ''
ELSE Column1
END
If I try to put a sting after THEN then it tells me that it cannot convert it from int. I need to convert it to varchar and then change its output to a blank space afterwards, such as:
e.g.
CASE
WHEN Column1 IS NULL
THEN CONVERT(varchar(10), Column1)
THEN ''
ELSE Column1
END
Is there a way of doing this?
Thanks
Rob
A case expression returns a single value -- with a given type. If you want a string result, then you need to be sure that all paths in the case return strings:
CASE WHEN Column1 IS NULL
THEN ''
ELSE CAST(Column1 AS VARCHAR(255))
END
This is more simply written using COALESCE():
COALESCE(CAST(Column1 as VARCHAR(255)), '')
You cannot display an integer as a "blank" (other than using a NULL value).
I am trying to optimize a humongous SQL query that was written by a self taught developer that used a ton of functions instead of JOINS. Anyway, I am having trouble displaying a space or a empty string('') when there is no value in the field selected. I've included only the SELECT in question. I am having the weirdest problem or just overlooking the correct answer in troubleshooting. Whenever I use COALESCE, when the field is supposed to be a blank string, it displays a zero. And when I use IS NULL, I get back NULL. All info online seems to point toward using COALESCE(value, '') as depicted in the code. But I am getting a 0 instead of ''. Does anyone see what I'm doing wrong? I'm using SSMS.
SELECT
pss8.dbo.xml_StripIllegalChars(dbo.rpt_get_series_volume(b.bookkey)) AS p_seriesvol --SELECT to be replaced that works but is slow due to function use I am told
,COALESCE(bd.seriesvolume, '') AS p_seriesvol --my SELECT that won't work!
FROM
bookdetail bd
WHERE
--bd.bookkey='303177'
bd.bookkey='6002'
The bookkeys at the bottom are for testing as I know the top one returns a 1 and the bottom one returns a '' previously when it worked. The SELECT above my commented SELECT is the code that works but is slow... According to what I read online, I am saying 'if there isn't a series volume number, then it equals an empty string.' Does COALESCE not work like this? Can it only return a 0 if the field has no value, or in this case, has no volume number? All help much appreciated. I'm very curious to hear a solution!
Here's more intel. This is how the this SELECT works:
pss8.dbo.xml_StripIllegalChars(dbo.rpt_get_series_volume(b.bookkey)) AS p_seriesvol
The
.rpt_get_series_vol
function manages to create an empty string with this code... Does this reveal anything?
DECLARE #RETURN
VARCHAR(5)
DECLARE #v_desc
VARCHAR(5)
DECLARE #i_volumenumber INT
SELECT #i_volumenumber = volumenumber
FROM bookdetail
WHERE bookkey = #i_bookkey and volumenumber <> 0
IF #i_volumenumber > 0
BEGIN
SELECT #RETURN = CAST(#i_volumenumber as varchar(5))
END
ELSE
BEGIN
SELECT #RETURN = ''
END
RETURN #RETURN
END
As you are looking for a '0' not a NULL COALESCE()is not useful, instead use a simple CASE:
select
...,
case bd.seriesvolume when '0' then '' else bd.seriesvolume end as p_seriesvol
from
...
Or if you want '' for 0 or NULL
case when bd.seriesvolume is null or bd.seriesvolume = '0' then '' else bd.seriesvolume end as p_seriesvo
COALESCE() function returns the 1st non null value
SELECT COALESCE(NULL, NULL, 'third_value', 'fourth_value'); returns the third value because the third value is the first value that is not null.
So in your case COALESCE(bd.seriesvolume, '') AS p_seriesvol if seriesvolume colum value is null then it will return blank string
I am working in SQL Server 2008. I am trying to test whether a string (varchar) has only digit characters (0-9). I know that the IS_NUMERIC function can give spurious results. (My data can possibly have $ signs, which should not pass the test.) So, I'm avoiding that function.
I already have a test to see if a string has any non-digit characters, i.e.,
some_column LIKE '%[^0123456789]%'
I would think that the only-digits test would be something similar, but I'm drawing a blank. Any ideas?
Use Not Like
where some_column NOT LIKE '%[^0-9]%'
Demo
declare #str varchar(50)='50'--'asdarew345'
select 1 where #str NOT LIKE '%[^0-9]%'
There is a system function called ISNUMERIC for SQL 2008 and up. An example:
SELECT myCol
FROM mTable
WHERE ISNUMERIC(myCol)<> 1;
I did a couple of quick tests and also looked further into the docs:
ISNUMERIC returns 1 when the input expression evaluates to a valid numeric data type; otherwise it returns 0.
Which means it is fairly predictable for example
-9879210433 would pass but 987921-0433 does not.
$9879210433 would pass but 9879210$433 does not.
So using this information you can weed out based on the list of valid currency symbols and + & - characters.
Solution:
where some_column NOT LIKE '%[^0-9]%'
Is correct.
Just one important note: Add validation for when the string column = '' (empty string). This scenario will return that '' is a valid number as well.
Method that will work. The way it is used above will not work.
declare #str varchar(50)='79136'
select
case
when #str LIKE replicate('[0-9]',LEN(#str)) then 1
else 0
end
declare #str2 varchar(50)='79D136'
select
case
when #str2 LIKE replicate('[0-9]',LEN(#str)) then 1
else 0
end
DECLARE #x int=1
declare #exit bit=1
WHILE #x<=len('123c') AND #exit=1
BEGIN
IF ascii(SUBSTRING('123c',#x,1)) BETWEEN 48 AND 57
BEGIN
set #x=#x+1
END
ELSE
BEGIN
SET #exit=0
PRINT 'string is not all numeric -:('
END
END
I was attempting to find strings with numbers ONLY, no punctuation or anything else. I finally found an answer that would work here.
Using PATINDEX('%[^0-9]%', some_column) = 0 allowed me to filter out everything but actual number strings.
The selected answer does not work.
declare #str varchar(50)='79D136'
select 1 where #str NOT LIKE '%[^0-9]%'
I don't have a solution but know of this potential pitfall. The same goes if you substitute the letter 'D' for 'E' which is scientific notation.
Is there an equivalent to IsDate or IsNumeric for uniqueidentifier (SQL Server)?
Or is there anything equivalent to (C#) TryParse?
Otherwise I'll have to write my own function, but I want to make sure I'm not reinventing the wheel.
The scenario I'm trying to cover is the following:
SELECT something FROM table WHERE IsUniqueidentifier(column) = 1
SQL Server 2012 makes this all much easier with TRY_CONVERT(UNIQUEIDENTIFIER, expression)
SELECT something
FROM your_table
WHERE TRY_CONVERT(UNIQUEIDENTIFIER, your_column) IS NOT NULL;
For prior versions of SQL Server, the existing answers miss a few points that mean they may either not match strings that SQL Server will in fact cast to UNIQUEIDENTIFIER without complaint or may still end up causing invalid cast errors.
SQL Server accepts GUIDs either wrapped in {} or without this.
Additionally it ignores extraneous characters at the end of the string. Both SELECT CAST('{5D944516-98E6-44C5-849F-9C277833C01B}ssssssssss' as uniqueidentifier) and SELECT CAST('5D944516-98E6-44C5-849F-9C277833C01BXXXXXXXXXXXXXXXXXXXXXXXXXXXXX' as uniqueidentifier) succeed for instance.
Under most default collations the LIKE '[a-zA-Z0-9]' will end up matching characters such as À or Ë
Finally if casting rows in a result to uniqueidentifier it is important to put the cast attempt in a case expression as the cast may occur before the rows are filtered by the WHERE.
So (borrowing #r0d30b0y's idea) a slightly more robust version might be
;WITH T(C)
AS (SELECT '5D944516-98E6-44C5-849F-9C277833C01B'
UNION ALL
SELECT '{5D944516-98E6-44C5-849F-9C277833C01B}'
UNION ALL
SELECT '5D944516-98E6-44C5-849F-9C277833C01BXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
UNION ALL
SELECT '{5D944516-98E6-44C5-849F-9C277833C01B}ssssssssss'
UNION ALL
SELECT 'ÀD944516-98E6-44C5-849F-9C277833C01B'
UNION ALL
SELECT 'fish')
SELECT CASE
WHEN C LIKE expression + '%'
OR C LIKE '{' + expression + '}%' THEN CAST(C AS UNIQUEIDENTIFIER)
END
FROM T
CROSS APPLY (SELECT REPLACE('00000000-0000-0000-0000-000000000000', '0', '[0-9a-fA-F]') COLLATE Latin1_General_BIN) C2(expression)
WHERE C LIKE expression + '%'
OR C LIKE '{' + expression + '}%'
Not mine, found this online... thought i'd share.
SELECT 1 WHERE #StringToCompare LIKE
REPLACE('00000000-0000-0000-0000-000000000000', '0', '[0-9a-fA-F]');
SELECT something
FROM table1
WHERE column1 LIKE '[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]';
UPDATE:
...but I much prefer the approach in the answer by #r0d30b0y:
SELECT something
FROM table1
WHERE column1 LIKE REPLACE('00000000-0000-0000-0000-000000000000', '0', '[0-9a-fA-F]');
I am not aware of anything that you could use "out of the box" - you'll have to write this on your own, I'm afraid.
If you can: try to write this inside a C# library and deploy it into SQL Server as a SQL-CLR assembly - then you could use things like Guid.TryParse() which is certainly much easier to use than anything in T-SQL....
A variant of r0d30b0y answer is to use PATINDEX to find within a string...
PATINDEX('%'+REPLACE('00000000-0000-0000-0000-000000000000', '0', '[0-9a-fA-F]')+'%',#StringToCompare) > 0
Had to use to find Guids within a URL string..
HTH
Dave
Like to keep it simple. A GUID has four - in it even, if is just a string
WHERE column like '%-%-%-%-%'
Though an older post, just a thought for a quick test ...
SELECT [A].[INPUT],
CAST([A].[INPUT] AS [UNIQUEIDENTIFIER])
FROM (
SELECT '5D944516-98E6-44C5-849F-9C277833C01B' Collate Latin1_General_100_BIN AS [INPUT]
UNION ALL
SELECT '{5D944516-98E6-44C5-849F-9C277833C01B}'
UNION ALL
SELECT '5D944516-98E6-44C5-849F-9C277833C01BXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
UNION ALL
SELECT '{5D944516-98E6-44C5-849F-9C277833C01B}ssssssssss'
UNION ALL
SELECT 'ÀD944516-98E6-44C5-849F-9C277833C01B'
UNION ALL
SELECT 'fish'
) [A]
WHERE PATINDEX('[^0-9A-F-{}]%', [A].[INPUT]) = 0
This is a function based on the concept of some earlier comments. This function is very fast.
CREATE FUNCTION [dbo].[IsGuid] (#input varchar(50))
RETURNS bit AS
BEGIN
RETURN
case when #input like '[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]'
then 1 else 0 end
END
GO
/*
Usage:
select [dbo].[IsGuid]('123') -- Returns 0
select [dbo].[IsGuid]('ebd8aebd-7ea3-439d-a7bc-e009dee0eae0') -- Returns 1
select * from SomeTable where dbo.IsGuid(TableField) = 0 -- Returns table with all non convertable items!
*/
DECLARE #guid_string nvarchar(256) = 'ACE79678-61D1-46E6-93EC-893AD559CC78'
SELECT
CASE WHEN #guid_string LIKE '________-____-____-____-____________'
THEN CONVERT(uniqueidentifier, #guid_string)
ELSE NULL
END
You can write your own UDF. This is a simple approximation to avoid the use of a SQL-CLR assembly.
CREATE FUNCTION dbo.isuniqueidentifier (#ui varchar(50))
RETURNS bit AS
BEGIN
RETURN case when
substring(#ui,9,1)='-' and
substring(#ui,14,1)='-' and
substring(#ui,19,1)='-' and
substring(#ui,24,1)='-' and
len(#ui) = 36 then 1 else 0 end
END
GO
You can then improve it to check if it´s just about HEX values.
I use :
ISNULL(convert(nvarchar(50), userID), 'NULL') = 'NULL'
I had some Test users that were generated with AutoFixture, which uses GUIDs by default for generated fields. My FirstName fields for the users that I need to delete are GUIDs or uniqueidentifiers. That's how I ended up here.
I was able to cobble together some of your answers into this.
SELECT UserId FROM [Membership].[UserInfo] Where TRY_CONVERT(uniqueidentifier, FirstName) is not null
Use RLIKE for MYSQL
SELECT 1 WHERE #StringToCompare
RLIKE REPLACE('00000000-0000-0000-0000-000000000000', '0', '[0-9a-fA-F]');
In a simplest scenario. When you sure that given string can`t contain 4 '-' signs.
SELECT * FROM City WHERE Name LIKE('%-%-%-%-%')
In BigQuery you can use
SELECT *
FROM table
WHERE
REGEXP_CONTAINS(uuid, REPLACE('^00000000-0000-0000-0000-000000000000$', '0', '[0-9a-fA-F]'))
how can I accomplish:
select * from table where column_value is int
I know I can probably inner join to the system tables and type tables but I'm wondering if there's a more elegant way.
Note that column_value is a varchar that "could" have an int, but not necessarily.
Maybe I can just cast it and trap the error? But again, that seems like a hack.
select * from table
where column_value not like '[^0-9]'
If negative ints are allowed, you need something like
where column_value like '[+-]%'
and substring(column_value,patindex('[+-]',substring(column_value,1))+1,len(column_value))
not like '[^0-9]'
You need more code if column_value can be an integer that exceeds the limits of the "int" type, and you want to exclude such cases.
Here if you want to implement your custom function
CREATE Function dbo.IsInteger(#Value VARCHAR(18))
RETURNS BIT
AS
BEGIN
RETURN ISNULL(
(SELECT CASE WHEN CHARINDEX('.', #Value) > 0 THEN
CASE WHEN CONVERT(int, PARSENAME(#Value, 1)) <> 0 THEN 0 ELSE 1 END
ELSE 1
END
WHERE ISNUMERIC(#Value + 'e0') = 1), 0)
END
ISNUMERIC returns 1 when the input
expression evaluates to a valid
integer, floating point number, money
or decimal type; otherwise it returns
0. A return value of 1 guarantees that expression can be converted to one of
these numeric types.
I would do a UDF as Svetlozar Angelov suggests, but I would check for ISNUMERIC first (and return 0 if not), and then check for column_value % 1 = 0 to see if it's an integer.
Here's what the body might look like. You have to put the modulo logic in a separate branch because it will throw an exception if the value isn't numeric.
DECLARE #RV BIT
IF ISNUMERIC(#value) BEGIN
IF CAST(#value AS NUMERIC) % 1 = 0 SET #RV = 1
ELSE SET #RV = 0
END
ELSE SET #RV = 0
RETURN #RV
This should handle all cases without throwing any exceptions:
--This handles dollar-signs, commas, decimal-points, and values too big or small,
-- all while safely returning an int.
DECLARE #IntString as VarChar(50) = '$1,000.'
SELECT CAST((CASE WHEN --This IsNumeric check here does most of the heavy lifting. The rest is Integer-Specific
ISNUMERIC(#IntString) = 1
--Only allow Int-related characters. This will exclude things like 'e' and other foreign currency characters.
AND #IntString NOT LIKE '%[^ $,.\-+0-9]%' ESCAPE '\'--'
--Checks that the value is not out of bounds for an Integer.
AND CAST(REPLACE(REPLACE(#IntString,'$',''),',','') as Decimal(38)) BETWEEN -2147483648 AND 2147483647
--This allows values with decimal-points for count as an Int, so long as there it is not a fractional value.
AND CAST(REPLACE(REPLACE(#IntString,'$',''),',','') as Decimal(38)) = CAST(REPLACE(REPLACE(#IntString,'$',''),',','') as Decimal(38,2))
--This will safely convert values with decimal points to casting later as an Int.
THEN CAST(REPLACE(REPLACE(#IntString,'$',''),',','') as Decimal(10))
END) as Int)[Integer]
Throw this into a Scalar UDF and call it ReturnInt().
If the value comes back as NULL, then it's not an int (so there's your IsInteger() requirement)
If you don't like typing "WHERE ReturnInt(SomeValue) IS NOT NULL", you could throw it into another scalar UDF called IsInt() to call this function and simply return "ReturnInt(SomeValue) IS NOT NULL".
The cool thing is, the UDF can serve double duty by returning the "safely" converted int value.
Just because something can be an int doesn't mean casting it as an int won't throw a huge exception. This takes care of that for you.
Also, I'd avoid the other solutions because this universal approach will handle commas, decimals, dollar signs, and checks the acceptable Int value's range while the other solutions do not - or they require multiple SET operations that prevent you from using the logic in a Scalar-Function for maximum performance.
See the examples below and test them against my code and others:
--Proves that appending "e0" or ".0e0" is NOT a good idea.
select ISNUMERIC('$1' + 'e0')--Returns: 0.
select ISNUMERIC('1,000' + 'e0')--Returns: 0.
select ISNUMERIC('1.0' + '.0e0')--Returns: 0.
--While these are numeric, they WILL break your code
-- if you try to cast them directly as int.
select ISNUMERIC('1,000')--Returns: 1.
select CAST('1,000' as Int)--Will throw exception.
select ISNUMERIC('$1')--Returns: 1.
select CAST('$1' as Int)--Will throw exception.
select ISNUMERIC('10.0')--Returns: 1.
select CAST('10.0' as Int)--Will throw exception.
select ISNUMERIC('9999999999223372036854775807')--Returns: 1. This is why I use Decimal(38) as Decimal defaults to Decimal(18).
select CAST('9999999999223372036854775807' as Int)--Will throw exception.
Update:
I read a comment here that you want to be able to parse a value like '123.' into an Integer. I have updated my code to handle this as well.
Note: This converts "1.0", but returns null on "1.9".
If you want to allow for rounding, then tweak the logic in the "THEN" clause to add Round() like so:
ROUND(CAST(REPLACE(REPLACE(#IntString,'$',''),',','') as Decimal(10)), 0)
You must also remove the "AND" that checks for "decimal-points" to allow for Rounding or Truncation.
Why not use the following and test for 1?
DECLARE #TestValue nvarchar(MAX)
SET #TestValue = '1.04343234e5'
SELECT CASE WHEN ISNUMERIC(#TestValue) = 1
THEN CASE WHEN ROUND(#TestValue,0,1) = #TestValue
THEN 1
ELSE 0
END
ELSE null
END AS Analysis
If you are purely looking to verify a string is all digits and not just CAST-able to INT you can do this terrible, terrible thing:
select LEN(
REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE(
'-1.223344556677889900e-1'
,'0','') ,'1','') ,'2','') ,'3','') ,'4','') ,'5','') ,'6','') ,'7','') ,'8','') ,'9','')
)
It returns 0 when the string was empty or pure digits.
To make it a useful check for "poor-man's" Integer you'd have to deal with empty string, and an initial negative sign. And manually make sure it isn't too long for your variety of INTEGER.