I'm tryin to use SQL to build a comma separated list of cat_id's
the code is:
declare #output varchar(max)
set #output = null;
select #output = COALESCE(#output + ', ', '') + convert(varchar(max),cat_id)
edit: changed '' to null, STILL same.
but the output im getting is like so:
, 66 , 23
the leading comma should not be there. What have i missed?
Are you on SQL 2005? With props to Rob Farley who showed me this just recently:
SELECT stuff((
SELECT ', ' + cast(cat_id as varchar(max))
FROM categories
FOR XML PATH('')
), 1, 2, '');
The inside query (with FOR XML PATH('')) selects a comma-separated list of category IDs, with a leading ", ". The outside query uses the stuff function to remove the leading comma and space.
I don't have an SQL instance handy to test this, so it's from memory. You may have to play with the stuff parameters etc to get it to work exactly how you want.
COALESCE Returns the first nonnull expression among its arguments
First argument #output + ', ' is never null (unless you initialize #output as null AND set CONCAT_NULL_YIELDS_NULL to ON), so it's always returned.
And sometimes...
you have to answer your own question
declare #output varchar(max)
select #output = case when (#output is null) then '' else ', ' END + convert(varchar(max),cat_id)
check #output value just before the execution of this query, I think it's not equal to NULL but to '' (empty string)
EDIT: (after the #auth edited the question)
now I'm sure it's '',
you have to initialize it to NULL
to do it independently of CONCAT_NULL_YIELDS_NULL, use the old CASE WHEN:
select #output = NULL
select #output = CASE WHEN #output IS NULL THEN '' ELSE #output+', ' END + value
declare #output varchar(max)
select #output = coalesce
(
#output + ', ' + convert(varchar(max),cat_id),
convert(varchar(max),cat_id)
)
from yourTableHere
print #output
Did you initialize #output to an empty string? COALESCE will only work if it's a NULL string.
What you are doing wrong is that #output is not null from start, but an empty string. Set #output to null before the loop (or if it's not used since it's declared just don't assign an empty string to it).
Not sure if this applies exactly to what you're looking for, but I found this right at the same time I found your questions. I use the second solution with FOR XML PATH, which Matt Hamilton mentioned above. It's worked great for me.
Concatenating Rows - By Carl P. Anderson, 2009/10/14
http://www.sqlservercentral.com/articles/T-SQL/67973/
On Unix, the sqlminus command lets you merge SQL commands and other formatting:
% sqlminus "select ri || ',' ||name|| ',' || numports || ',' || ascii(OVRONSET) from sdfctigw.ivrgrp where GRP_BEP is not null;" | sort -h
1,COMO INTERNAL 2,700,90
7,LOADIVR,10,80
10,SPEECH_IVR_PROD,600,95
Related
I have a string of data
'["Dog",,,1,"Person","2020-03-17",,4,"Todd]'
I am trying to use the replace function to replace double commas with NULL values
Solution
'["Dog",NULL,NULL,1,"Person","2020-03-17",NULL,4,"Todd]'
But I keep ending up with
'"Dog",NULL,,1,"Person","2020-03-17",NULL,4,"Todd'
(The ,,, needs to become ,NULL,NULL, but only becomes ,NULL,,)
Here is my sample code I'm using
REPLACE(FileData, ',,' , ',NULL,')
WHERE FileData LIKE '%,,%'
If you do the same replacement twice, any number of sequential commas will get handled.
REPLACE(REPLACE(FileData, ',,' , ',NULL,'), ',,' , ',NULL,')
The first REPLACE deals with all the odd positions...
',,,,,,,,'` => ',NULL,,NULL,,NULL,,NULL,'
Doing it again will deal with all of the remaining positions.
=> ',NULL,NULL,NULL,NULL,NULL,NULL,NULL,'
Note, by specifically handling a special case of three consecutive commas (as in an other answer here) you won't handle four or five or six, etc. The above solution generalises to Any length of consecutive commas.
To be fully robust, you may also need to consider when there is a missing NULL at the first or last place in the string.
[,ThatOneToMyLeft,and,ThatOneToMyRight,]
A laborious but robust approach could be to replace [, and ,] with [,, and ,,] respectively, then do the double-replacement, then undo the first steps...
REPLACE(
REPLACE(
REPLACE(
REPLACE(
REPLACE(
REPLACE(
FileData,
'[,',
'[,,'
),
',]',
',,]'
),
',,',
',NULL,'
),
',,',
',NULL,'
),
',]',
']',
),
'[,',
'['
)
There are ways to make even that less verbose, but I have to run right now :)
You can try the following:
REPLACE(REPLACE(FileData, ',,,' , ',NULL,,'), ',,' , ',NULL,')
Where FileData LIKE '%,,%'
You can create a function for your problem solving that associates to string replacement function.
Check this:
update table1
set column1 = dbo.ReplaceEx(column1, ',', 'NULL')
where column1 like '%,,%'
create function dbo.ReplaceEx(#string varchar(2000), #separator varchar(4), #nullValue varchar(10))
returns varchar(4000)
with execute as caller
as
begin
declare #result varchar(4000);
set #result = '';
select #result = concat_ws(#sep, #result,
case when rtrim(value) = '' then #nullValue
else case when ltrim(rtrim(value)) = '[' then '[' + #nullValue
else case when ltrim(rtrim(value)) = ']' then #nullValue + ']'
else value end end end
)
from string_split(#string, #separator);
return (#result);
end;
I've written the following function in SSMS to replace any commas that are outside of quotation marks with ||||:
CREATE FUNCTION dbo.fixqualifier (#string nvarchar(max))
returns nvarchar(max)
as begin
DECLARE #STRINGTOPAD NVARCHAR(MAX)
DECLARE #position int = 1,#newstring nvarchar(max) ='',#QUOTATIONMODE INT = 0
WHILE(LEN(#string)>0)
BEGIN
SET #STRINGTOPAD = SUBSTRING(#string,0,IIF(#STRING LIKE '%"%',CHARINDEX('"',#string),LEN(#STRING)))
SET #newstring = #newstring + IIF(#QUOTATIONMODE = 1, REPLACE(#STRINGTOPAD,',','||||'),#STRINGTOPAD)
SET #QUOTATIONMODE = IIF(#QUOTATIONMODE = 1,0,1)
set #string = SUBSTRING(#string,1+IIF(#STRING LIKE '%"%',CHARINDEX('"',#string),LEN(#STRING)),LEN(#string))
END
return #newstring
end
The idea is for the function to find the first ", replace all ',' before that then switch to quotation mode 1 so it knows to not replace the , until it changes back to quotation mode 0 when it hits the 2nd " and so on.
so for example the string:
qwer,tyu,io,asd,"edffs,asdfgh","jjkzx",kl
would become:
qwer||||tyu||||io||||asd||||"edffs,asdfgh"||||"jjkzx"||||kl
It works as expected but it's really inefficient when it comes to doing this for several thousand rows.
Is there a better way or doing this or at least speeding the function up.
Do a simple trick by Modulus
DECLARE #VAR VARCHAR(100) = 'qwer,tyu,io,asd,"edffs,asdfgh","jjkzx",kl'
,#OUTPUT VARCHAR(100) = '';
SELECT #OUTPUT = #OUTPUT + CASE WHEN (LEN(#OUTPUT) - LEN(REPLACE(#OUTPUT, '"', ''))) % 2 = 0
THEN REPLACE(VAL, ',', '||||') ELSE VAL END
FROM (
SELECT SUBSTRING(#VAR, NUMBER, 1) VAL
FROM master.dbo.spt_values
WHERE type = 'P'
AND NUMBER BETWEEN 1 AND LEN(#VAR)
) A
PRINT #OUTPUT
Result:
qwer||||tyu||||io||||asd||||"edffs,asdfgh"||||"jjkzx"||||kl
By this LEN(#OUTPUT) - LEN(REPLACE(#OUTPUT, '"', '')) expression, you will get count of ". By taking Modulus of the count %2, if it is zero its even then you can replace commas, otherwise you will keep them.
This uses DelimitedSplit8k and completely avoids any RBAR methods (such as a WHILE or #Variable = #Variable +... (which is a hidden form of RBAR)).
It firstly splits on the quotation, and then on the commas, where the string isn't quoted. Finally it then puts the strings back together again, using the "old" STUFF and FOR XML PATH method:
USE Sandbox;
DECLARE #String varchar(8000) = 'qwer,tyu,io,asd,"edffs,asdfgh","jjkzx",kl';
WITH Splits AS(
SELECT QS.ItemNumber AS QuoteNumber, CS.ItemNumber AS CommaNumber, ISNULL(CS.Item, '"' + QS.Item + '"') AS DelimitedItem
FROM dbo.DelimitedSplit8K(#string,'"') QS
OUTER APPLY (SELECT *
FROM dbo.DelimitedSplit8K(QS.Item,',')
WHERE QS.ItemNumber % 2 = 1) CS
WHERE QS.Item <> ',')
SELECT STUFF((SELECT '||||' + S.DelimitedItem
FROM Splits S
ORDER BY S.QuoteNumber, S.CommaNumber
FOR XML PATH('')),1,1,'') AS DelimitedList;
(Note, DelimitedSplit8K does not accept more than 8,000 characters. If you have more than that, SQL Server is really not the right tool. STRING_SPLIT does not provide the ordinal position, so you would be unable to guarantee the rebuild order with it.)
First - sorry for my english. Second - i'm learning t-SQL.
Goal:
I want to get difference between two strings, then check in which column is this difference. If the difference is in first column, do something, if in second column - do something else.
What I'm actually doing
Column 'messages' is a string which contains list of ID. So i am replacing all '#' with ',' and deleting last ',' what gives to me ActualID and BeforeID column. See below:
DECLARE #string VARCHAR(512);
DECLARE #string2 VARCHAR(512);
DECLARE #string3 VARCHAR(512);
SET #string = '41#42#43#44#45#46#47#48#49#50#51#52#53#54#55#56#57#58#59#';
SET #string2 = REPLACE((SELECT messages FROM USERS WHERE userid = 4), '#', ', ' )
SET #string3 = left(#string2, len(#string2) - 1);
SET #string2 = REPLACE(#string, '#', ', ' )
SET #string = left(#string2, len(#string2) - 1);
SELECT #string3 as ActualID, #string as BeforeID
So now, I want compare BeforeID with ActualID. For example:
In BeforeID we have 1, 2, 3 / In ActualID 1, 2, 3, 4
In example above 4 was added. So, if it was added I want to add it to #AddedElements.
If 4, 5, 7 were added then SELECT #AddedElements as AddedElements should return 4, 5, 7 (With comas)
But, that's not all.
If BeforeID = 1, 5, 10, 14 and ActualID = 1, 5, 14 I want, that element which is in BeforeID, but not in AcutalID will be added to #DeletedElements.
So SELECT #DeletedElements as DeletedElements should return 10
Added elements/Deleted elements should be returned once. I mean, full result what I want to Earn should be
SELECT #AddedElements as AddedElements, #DeletedElements as DeletedElements
Is it possible? If, then how to do it?
First of all, I have to start by saying that this is just poor design; but having said that, I've also found myself in all kinds of situations where I couldn't change the way things worked, only try to make them work better in the current configuration. Therefore, I recommend something like this:
1: Create a UDF (User-Defined Function) that can handle splitting the strings and returning them in table-formed data that you can work with:
CREATE FUNCTION [dbo].[UDF_StringDelimiter]
/*********************************************************
** Takes Parameter "LIST" and transforms it for use **
** to select individual values or ranges of values. **
** **
** EX: 'This,is,a,test' = 'This' 'Is' 'A' 'Test' **
*********************************************************/
(
#LIST VARCHAR(8000)
,#DELIMITER VARCHAR(255)
)
RETURNS #TABLE TABLE
(
[RowID] INT IDENTITY
,[Value] VARCHAR(255)
)
WITH SCHEMABINDING
AS
BEGIN
DECLARE
#LISTLENGTH AS SMALLINT
,#LISTCURSOR AS SMALLINT
,#VALUE AS VARCHAR(255)
;
SELECT
#LISTLENGTH = LEN(#LIST) - LEN(REPLACE(#LIST,#DELIMITER,'')) + 1
,#LISTCURSOR = 1
,#VALUE = ''
;
WHILE #LISTCURSOR <= #LISTLENGTH
BEGIN
INSERT INTO #TABLE (Value)
SELECT
CASE
WHEN #LISTCURSOR < #LISTLENGTH
THEN SUBSTRING(#LIST,1,PATINDEX('%' + #DELIMITER + '%',#LIST) - 1)
ELSE SUBSTRING(#LIST,1,LEN(#LIST))
END
;
SET #LIST = STUFF(#LIST,1,PATINDEX('%' + #DELIMITER + '%',#LIST),'')
;
SET #LISTCURSOR = #LISTCURSOR + 1
;
END
;
RETURN
;
END
;
2: Consider dropping the whole "Switching out commas" thing, because it's pointless - the function I've written here takes two arguments: The string itself, and the delimiter (the mini-string that separates the individual strings within the big string, in your case '#') Then you just have to do a couple of quick comparisons to find out what was added and what was deleted.
DECLARE
#AddedElements VARCHAR(255) = ''
,#DeletedElements VARCHAR(255) = ''
,#ActualID VARCHAR(255) = '41#42#43#44#45#46#47#48#49#50#51#52#53#54#55#56#57#58#59#'
,#BeforeID VARCHAR(255) = '41#42#43#44#45#46#47#48#50#51#52#53#54#55#56#57#58#59#60#'
;
SET #AddedElements = #AddedElements +
SUBSTRING(
(
SELECT ', ' + Value
FROM dbo.UDF_StringDelimiter(#ActualID,'#')
WHERE Value NOT IN
(
SELECT Value
FROM dbo.UDF_StringDelimiter(#BeforeID,'#')
)
GROUP BY ', ' + Value
FOR XML PATH('')
)
,3,255)
;
SET #DeletedElements = #DeletedElements +
SUBSTRING(
(
SELECT ', ' + Value
FROM dbo.UDF_StringDelimiter(#BeforeID,'#')
WHERE Value NOT IN
(
SELECT Value
FROM dbo.UDF_StringDelimiter(#ActualID,'#')
)
GROUP BY ', ' + Value
FOR XML PATH('')
)
,3,255)
;
SELECT #AddedElements AS AddedElements,#DeletedElements AS DeletedElements
;
Using this method, if you add a value to #ActualID that does not exist in #BeforeID, it will show up in #AddedElements.
Likewise , if you remove an element from #ActualID that had previously existed in #BeforeID, it will show up in #DeletedElements.
All of this is, of course, assuming that the dynamic string (the one really being compared here) is the #ActualID. I operated with the understanding that #BeforeID is actually a stored value in the DB, and #ActualID is a dynamic string being passed in from...somewhere. If this is wrong, update me and I'll change the tactic appropriately.
Quick note: It's important to me to point out that this is just one way of dealing with a situation like this, and I'm sure there are better ways; but with the information I have, it's the best I could come up with without spending too much time and energy on it.
Currently, I have a function to get list of columns of 1 table with detail attribute. And off course, there are some tables with a lot of columns. So, the output will be over 10.000 characters.
Here I test like this:
declare #aa nvarchar(max)
set #aa = dbo.fnGetColumnList('Table_Name')
print #aa
The result always has around 4000 characters. It looks like the SQL has truncated it.
What I know that when we declare nvarchar(max), SQL will supports up to 2^32-1 (2GB) for this string. But why it just has around 4000 characters?
When I execute like this:
select dbo.fnGetColumnList('Table_Name')
the result is correct.
And here is the code for the function:
-- get column list from table Mapping
ALTER FUNCTION [dbo].[fnGetColumnList] ( #tblName varchar (30))
RETURNS nvarchar(max)
AS
BEGIN
Declare #sql nvarchar(max)
set #sql = ''
SELECT #sql = #sql + case
when CHARINDEX('char', LOWER([DBType])) > 0 then ', ['+[DBColumn]+']' + ' ['+[DBType]+']' + ' ('+convert(varchar(10),[Length])+') NULL' + CHAR(13)
when CHARINDEX('char', LOWER([DBType])) > 0 then ', ['+[DBColumn]+']' + ' ['+[DBType]+']' + ' NULL' + CHAR(13)
ELSE ', ['+[DBColumn]+']' + ' ['+[DBType]+']' + ' NULL' + CHAR(13)
end FROM dbo.Mapping WHERE [DBTable] = #tblName
return #sql
END
Please advance.
This is almost always a variable assignment type problem, as explained in:
For Nvarchar(Max) I am only getting 4000 characters in TSQL?
If it's not that, then it's probably just the settings of Print to display too few characters:
nvarchar(max) still being truncated
Having looked at the updated code, it seems like it's the second issue, your print is truncating as it's not set to show enough characters.
You should see this by running
SELECT LEN(#aa)
You'll get a number larger than 4000, showing the value is held correctly in the variable.
As explained in Microsoft's nvar and nvarchar docs:
A common misconception is to think that with nchar(n) and nvarchar(n), the n defines the number of characters. However, in nchar(n) and nvarchar(n), the n defines the string length in byte-pairs (0-4,000). n never defines numbers of characters that can be stored. This is similar to the definition of char(n) and varchar(n).
There is an option in SQL Management Studio:
Tools > Options... > Query Results > SQL Server > Results to Text > Maximum number of characters displayed in each column
I have a table in a SQL Server database with an NTEXT column. This column may contain data that is enclosed with double quotes. When I query for this column, I want to remove these leading and trailing quotes.
For example:
"this is a test message"
should become
this is a test message
I know of the LTRIM and RTRIM functions but these workl only for spaces. Any suggestions on which functions I can use to achieve this.
I have just tested this code in MS SQL 2008 and validated it.
Remove left-most quote:
UPDATE MyTable
SET FieldName = SUBSTRING(FieldName, 2, LEN(FieldName))
WHERE LEFT(FieldName, 1) = '"'
Remove right-most quote: (Revised to avoid error from implicit type conversion to int)
UPDATE MyTable
SET FieldName = SUBSTRING(FieldName, 1, LEN(FieldName)-1)
WHERE RIGHT(FieldName, 1) = '"'
I thought this is a simpler script if you want to remove all quotes
UPDATE Table_Name
SET col_name = REPLACE(col_name, '"', '')
You can simply use the "Replace" function in SQL Server.
like this ::
select REPLACE('this is a test message','"','')
note: second parameter here is "double quotes" inside two single quotes and third parameter is simply a combination of two single quotes. The idea here is to replace the double quotes with a blank.
Very simple and easy to execute !
My solution is to use the difference in the the column values length compared the same column length but with the double quotes replaced with spaces and trimmed in order to calculate the start and length values as parameters in a SUBSTRING function.
The advantage of doing it this way is that you can remove any leading or trailing character even if it occurs multiple times whilst leaving any characters that are contained within the text.
Here is my answer with some test data:
SELECT
x AS before
,SUBSTRING(x
,LEN(x) - (LEN(LTRIM(REPLACE(x, '"', ' ')) + '|') - 1) + 1 --start_pos
,LEN(LTRIM(REPLACE(x, '"', ' '))) --length
) AS after
FROM
(
SELECT 'test' AS x UNION ALL
SELECT '"' AS x UNION ALL
SELECT '"test' AS x UNION ALL
SELECT 'test"' AS x UNION ALL
SELECT '"test"' AS x UNION ALL
SELECT '""test' AS x UNION ALL
SELECT 'test""' AS x UNION ALL
SELECT '""test""' AS x UNION ALL
SELECT '"te"st"' AS x UNION ALL
SELECT 'te"st' AS x
) a
Which produces the following results:
before after
-----------------
test test
"
"test test
test" test
"test" test
""test test
test"" test
""test"" test
"te"st" te"st
te"st te"st
One thing to note that when getting the length I only need to use LTRIM and not LTRIM and RTRIM combined, this is because the LEN function does not count trailing spaces.
I know this is an older question post, but my daughter came to me with the question, and referenced this page as having possible answers. Given that she's hunting an answer for this, it's a safe assumption others might still be as well.
All are great approaches, and as with everything there's about as many way to skin a cat as there are cats to skin.
If you're looking for a left trim and a right trim of a character or string, and your trailing character/string is uniform in length, here's my suggestion:
SELECT SUBSTRING(ColName,VAR, LEN(ColName)-VAR)
Or in this question...
SELECT SUBSTRING('"this is a test message"',2, LEN('"this is a test message"')-2)
With this, you simply adjust the SUBSTRING starting point (2), and LEN position (-2) to whatever value you need to remove from your string.
It's non-iterative and doesn't require explicit case testing and above all it's inline all of which make for a cleaner execution plan.
The following script removes quotation marks only from around the column value if table is called [Messages] and the column is called [Description].
-- If the content is in the form of "anything" (LIKE '"%"')
-- Then take the whole text without the first and last characters
-- (from the 2nd character and the LEN([Description]) - 2th character)
UPDATE [Messages]
SET [Description] = SUBSTRING([Description], 2, LEN([Description]) - 2)
WHERE [Description] LIKE '"%"'
You can use following query which worked for me-
For updating-
UPDATE table SET colName= REPLACE(LTRIM(RTRIM(REPLACE(colName, '"', ''))), '', '"') WHERE...
For selecting-
SELECT REPLACE(LTRIM(RTRIM(REPLACE(colName, '"', ''))), '', '"') FROM TableName
you could replace the quotes with an empty string...
SELECT AllRemoved = REPLACE(CAST(MyColumn AS varchar(max)), '"', ''),
LeadingAndTrailingRemoved = CASE
WHEN MyTest like '"%"' THEN SUBSTRING(Mytest, 2, LEN(CAST(MyTest AS nvarchar(max)))-2)
ELSE MyTest
END
FROM MyTable
Some UDFs for re-usability.
Left Trimming by character (any number)
CREATE FUNCTION [dbo].[LTRIMCHAR] (#Input NVARCHAR(max), #TrimChar CHAR(1) = ',')
RETURNS NVARCHAR(max)
AS
BEGIN
RETURN REPLACE(REPLACE(LTRIM(REPLACE(REPLACE(#Input,' ','¦'), #TrimChar, ' ')), ' ', #TrimChar),'¦',' ')
END
Right Trimming by character (any number)
CREATE FUNCTION [dbo].[RTRIMCHAR] (#Input NVARCHAR(max), #TrimChar CHAR(1) = ',')
RETURNS NVARCHAR(max)
AS
BEGIN
RETURN REPLACE(REPLACE(RTRIM(REPLACE(REPLACE(#Input,' ','¦'), #TrimChar, ' ')), ' ', #TrimChar),'¦',' ')
END
Note the dummy character '¦' (Alt+0166) cannot be present in the data (you may wish to test your input string, first, if unsure or use a different character).
To remove both quotes you could do this
SUBSTRING(fieldName, 2, lEN(fieldName) - 2)
you can either assign or project the resulting value
You can use TRIM('"' FROM '"this "is" a test"') which returns: this "is" a test
CREATE FUNCTION dbo.TRIM(#String VARCHAR(MAX), #Char varchar(5))
RETURNS VARCHAR(MAX)
BEGIN
RETURN SUBSTRING(#String,PATINDEX('%[^' + #Char + ' ]%',#String)
,(DATALENGTH(#String)+2 - (PATINDEX('%[^' + #Char + ' ]%'
,REVERSE(#String)) + PATINDEX('%[^' + #Char + ' ]%',#String)
)))
END
GO
Select dbo.TRIM('"this is a test message"','"')
Reference : http://raresql.com/2013/05/20/sql-server-trim-how-to-remove-leading-and-trailing-charactersspaces-from-string/
I use this:
UPDATE DataImport
SET PRIO =
CASE WHEN LEN(PRIO) < 2
THEN
(CASE PRIO WHEN '""' THEN '' ELSE PRIO END)
ELSE REPLACE(PRIO, '"' + SUBSTRING(PRIO, 2, LEN(PRIO) - 2) + '"',
SUBSTRING(PRIO, 2, LEN(PRIO) - 2))
END
Try this:
SELECT left(right(cast(SampleText as nVarchar),LEN(cast(sampleText as nVarchar))-1),LEN(cast(sampleText as nVarchar))-2)
FROM TableName