I have to trim Japanese characters string which has double byte space at start of string and end of string.
I have to do this by procedure of SQL server 2016.
For Example,
SELECT LTRIM(RTRIM(' A A '))
above one is working perfect
But Problem is in bellows line
SELECT LTRIM(RTRIM(' A A '))
i want output of above one is 'A A'
Have any idea, how to do this ?
Adapted SQL from OP's post:
SELECT LTRIM(RTRIM(REPLACE(' A A ', ' ', ' ')))
Screenshot with result:
The space in that string is the Ideographic space (U+3000) Unicode character, which LTRIM and RTRIM don't recognize as whitespace. Even TRIM in SQL Server 2017 won't recognize it unless it's specified explicitly.
Another problem is that this character is outside the normal range of characters and can't appear in a varchar field or value. This leads to inconsistent results between SQL Server versions. In SQL Server 2014 it will even appear as a ?. In later versions LTRIM/RTRIM may or may not work without emitting the error character. I don't have access to all versions to test this.
In SQL Server 2017 it's possible to explicitly specify the trimmed character, eg :
select trim(N' ' from N' A A ')
This produces A A.
In previous versions, PATINDEX can be used to find the locations of the first and last non-space positions :
declare #str nvarchar(10)=N' A A ';
declare #start int=PATINDEX(N'%[^ ]%',#str)
declare #end int=PATINDEX(N'% ',#str)
SELECT SUBSTRING(#str,#start,#end-#start)
The pattern N'%[^ ]%' finds the first non-U+3000 character in the string. N'% ' finds the position of the last one. SUBSTRING(#str,#start,#end-#start) extracts the content between the two positions.
The result is:
A A
I got solution
Thank you so much for your efforts.
Please use this function for double byte space remove.
CREATE FUNCTION [RTRIMBYTE](#AV_VALUE NVARCHAR(MAX))
RETURNS NVARCHAR(MAX)
AS
BEGIN
DECLARE #AV_RETURN NVARCHAR(MAX) = #AV_VALUE;
WHILE DATALENGTH(#AV_RETURN) > 0 AND RIGHT(#AV_RETURN, 1) in (' ', ' ')
SET #AV_RETURN = LEFT(#AV_RETURN, LEN('X' + #AV_RETURN + 'X') -3 ) ;
RETURN #AV_RETURN;
END;
I want to print box-drawing character in Output messages in SSMS. It includes characters like e.g. ║ or ░ or ╬.
The full list of characters which I have in my mind can be found here.
When I am trying the following: PRINT '╬' it returns simply + while I am expecting ╬.
When I am executing SELECT ASCII('╬') it returns 43, but when I am executing SELECT CHAR(43) it returns (not surprisingly) +.
Is it related to collation? If so, how can I find which collation to use?
A simple literal in SQL-Server is - by default a CHAR / VARCHAR type. This type is 1-byte-encoded extended ASCII: The lower half is the plain latin character set, the upper half is depending on a collation. This means, there is very little support for non-standard characters.
The second character type is NCHAR / NVARCHAR. This is (almost) unicode, very close to utf-16. The actual encoding is two-byte encoded UCS-2. The support for non-standard characters is (almost) complete. Any literal starting with a N is treated as NCHAR / NVARCHAR:
Try this:
SELECT '╬',N'╬';
DECLARE #str1a VARCHAR(10)='╬';
DECLARE #str1b VARCHAR(10)=N'╬'; --The NVARCHAR literal is changed to VARCHAR
DECLARE #str2 NVARCHAR(10)=N'╬';
SELECT #str1a,#str1b,#str2;
The functions to get the code point and - vice versa - to get the character are two-folded too:
SELECT ASCII('a'), UNICODE(N'a')
,ASCII('╬'), UNICODE(N'╬')
,CHAR(97),NCHAR(97),CHAR(43),NCHAR(43)
,NCHAR(9580)--does not work with `CHAR`
You need to print then in Unicode, i.e. to prefix them with N:
PRINT N'╬'
I have the following test table in SQL Server 2005:
CREATE TABLE [dbo].[TestTable]
(
[ID] [int] NOT NULL,
[TestField] [varchar](100) NOT NULL
)
Populated with:
INSERT INTO TestTable (ID, TestField) VALUES (1, 'A value'); -- Len = 7
INSERT INTO TestTable (ID, TestField) VALUES (2, 'Another value '); -- Len = 13 + 6 spaces
When I try to find the length of TestField with the SQL Server LEN() function it does not count the trailing spaces - e.g.:
-- Note: Also results the grid view of TestField do not show trailing spaces (SQL Server 2005).
SELECT
ID,
TestField,
LEN(TestField) As LenOfTestField, -- Does not include trailing spaces
FROM
TestTable
How do I include the trailing spaces in the length result?
This is clearly documented by Microsoft in MSDN at http://msdn.microsoft.com/en-us/library/ms190329(SQL.90).aspx, which states LEN "returns the number of characters of the specified string expression, excluding trailing blanks". It is, however, an easy detail on to miss if you're not wary.
You need to instead use the DATALENGTH function - see http://msdn.microsoft.com/en-us/library/ms173486(SQL.90).aspx - which "returns the number of bytes used to represent any expression".
Example:
SELECT
ID,
TestField,
LEN(TestField) As LenOfTestField, -- Does not include trailing spaces
DATALENGTH(TestField) As DataLengthOfTestField -- Shows the true length of data, including trailing spaces.
FROM
TestTable
You can use this trick:
LEN(Str + 'x') - 1
I use this method:
LEN(REPLACE(TestField, ' ', '.'))
I prefer this over DATALENGTH because this works with different data types, and I prefer it over adding a character to the end because you don't have to worry about the edge case where your string is already at the max length.
Note: I would test the performance before using it against a very large data set; though I just tested it against 2M rows and it was no slower than LEN without the REPLACE...
"How do I include the trailing spaces in the length result?"
You get someone to file a SQL Server enhancement request/bug report because nearly all the listed workarounds to this amazingly simple issue here have some deficiency or are inefficient. This still appears to be true in SQL Server 2012. The auto trimming feature may stem from ANSI/ISO SQL-92 but there seems to be some holes (or lack of counting them).
Please vote up "Add setting so LEN counts trailing whitespace" here:
https://feedback.azure.com/forums/908035-sql-server/suggestions/34673914-add-setting-so-len-counts-trailing-whitespace
Retired Connect link:
https://connect.microsoft.com/SQLServer/feedback/details/801381
There are problems with the two top voted answers. The answer recommending DATALENGTH is prone to programmer errors. The result of DATALENGTH must be divided by the 2 for NVARCHAR types, but not for VARCHAR types. This requires knowledge of the type you're getting the length of, and if that type changes, you have to diligently change the places you used DATALENGTH.
There is also a problem with the most upvoted answer (which I admit was my preferred way to do it until this problem bit me). If the thing you are getting the length of is of type NVARCHAR(4000), and it actually contains a string of 4000 characters, SQL will ignore the appended character rather than implicitly cast the result to NVARCHAR(MAX). The end result is an incorrect length. The same thing will happen with VARCHAR(8000).
What I've found works, is nearly as fast as plain old LEN, is faster than LEN(#s + 'x') - 1 for large strings, and does not assume the underlying character width is the following:
DATALENGTH(#s) / DATALENGTH(LEFT(LEFT(#s, 1) + 'x', 1))
This gets the datalength, and then divides by the datalength of a single character from the string. The append of 'x' covers the case where the string is empty (which would give a divide by zero in that case). This works whether #s is VARCHAR or NVARCHAR. Doing the LEFT of 1 character before the append shaves some time when the string is large. The problem with this though, is that it does not work correctly with strings containing surrogate pairs.
There is another way mentioned in a comment to the accepted answer, using REPLACE(#s,' ','x'). That technique gives the correct answer, but is a couple orders of magnitude slower than the other techniques when the string is large.
Given the problems introduced by surrogate pairs on any technique that uses DATALENGTH, I think the safest method that gives correct answers that I know of is the following:
LEN(CONVERT(NVARCHAR(MAX), #s) + 'x') - 1
This is faster than the REPLACE technique, and much faster with longer strings. Basically this technique is the LEN(#s + 'x') - 1 technique, but with protection for the edge case where the string has a length of 4000 (for nvarchar) or 8000 (for varchar), so that the correct answer is given even for that. It also should handle strings with surrogate pairs correctly.
LEN cuts trailing spaces by default, so I found this worked as you move them to the front
(LEN(REVERSE(TestField))
So if you wanted to, you could say
SELECT
t.TestField,
LEN(REVERSE(t.TestField)) AS [Reverse],
LEN(t.TestField) AS [Count]
FROM TestTable t
WHERE LEN(REVERSE(t.TestField)) <> LEN(t.TestField)
Don't use this for leading spaces of course.
You need also to ensure that your data is actually saved with the trailing blanks. When ANSI PADDING is OFF (non-default):
Trailing blanks in character values
inserted into a varchar column are
trimmed.
You should define a CLR function that returns the String's Length field, if you dislike string concatination.
I use LEN('x' + #string + 'x') - 2 in my production use-cases.
If you dislike the DATALENGTH because of of n/varchar concerns, how about:
select DATALENGTH(#var)/isnull(nullif(DATALENGTH(left(#var,1)),0),1)
which is just
select DATALENGTH(#var)/DATALENGTH(left(#var,1))
wrapped with divide-by-zero protection.
By dividing by the DATALENGTH of a single char, we get the length normalised.
(Of course, still issues with surrogate-pairs if that's a concern.)
This is the best algorithm I've come up with which copes with the maximum length and variable byte count per character issues:
ISNULL(LEN(STUFF(#Input, 1, 1, '') + '.'), 0)
This is a variant of the LEN(#Input + '.') - 1 algorithm but by using STUFF to remove the first character we ensure that the modified string doesn't exceed maximum length and remove the need to subtract 1.
ISNULL(..., 0) is added to deal with the case where #Input = '' which causes STUFF to return NULL.
This does have the side effect that the result is also 0 when #Input is NULL which is inconsistent with LEN(NULL) which returns NULL, but this could be dealt with by logic outside this function if need be
Here are the results using LEN(#Input), LEN(#Input + '.') - 1, LEN(REPLACE(#Input, ' ', '.')) and the above STUFF variant, using a sample of #Input = CAST(' S' + SPACE(3998) AS NVARCHAR(4000)) over 1000 iterations
Algorithm
DataLength
ExpectedResult
Result
ms
LEN
8000
4000
2
14
+DOT-1
8000
4000
1
13
REPLACE
8000
4000
4000
514
STUFF+DOT
8000
4000
4000
0
In this case the STUFF algorithm is actually faster than LEN()!
I can only assume that internally SQL looks at the last character and if it is not a space then optimizes the calculation
But that's a good result eh?
Don't use the REPLACE option unless you know your strings are small - it's hugely inefficient
use
SELECT DATALENGTH('string ')
I have encountered a scenario below
Declare #var int = ' 123'
select #var
Declare #var1 int = ' 123'
select #var1
for the first case I have used spaces in front of the value and while execute it returns value as 123
In Second case I have used tab instead of space in front of value and while execute it throws conversion error
Can anyone let know what is the difference between these 2 scenario..
Even though you have put same number of spaces (using spaces and then Tab) the character codes for both of them is different and that is the reason that space and TAB are treated as separately in SQL Server.
More information about character codes and character encoding can be found at below 2 links:-
https://www.computerhope.com/jargon/c/charcode.htm
https://www.pcmag.com/encyclopedia/term/51983/standards-character-codes
Also if you think mathematically and logically:- having spaces before integer numbers does not make sense. It's like having zeros before numbers.
For Example:-' 123' (5 spaces and then 123) is like 00000123.
Yet one more reason that spaces are trimmed before the integer numbers
sp_helpdb returns strings like '50000.255 MB' in the db_size column.
These strings are culture-dependent; the above string will mean 2 different things in US and Germany (in the latter, the dot char is used as a group separator, similar to the comma in US).
Is there another method which returns a numeric value, culture-independent?
Use YourDB;
SELECT SUM(Size / 128.0) As FileSize from sys.database_files;
This returns the size in MB as a numeric, you should be able to do what you like with it from there.
Note: size returns the number of 8KB pages in a given database file.
http://msdn.microsoft.com/en-us/library/ms174397.aspx
I do not think it is possible. The SP sp_helpdb uses str to convert the numeric size to varchar and there is nothing in the documentation (that I can find) that can make str use , instead of . as decimal symbol. Using set language does not help.
Workaround as suggested by Martin in comment
select replace(str(sum(convert(dec(17,2),size)) / 128,10,2) +' MB', '.', ',')
from sys.database_files