SQL computed column - formula to calculate length and do a substring - sql-server

Hi I'm looking for a easier solution to one of the columns in SQL table. The column has a datatype of nvarchar(50). However, I want to put a formula in the computed column field of this column whereby:
check if the length of the data being inserted is more than 50.
If it is, then take the first 36 characters.
create the string - "[SQL-Truncated]…"+"the 34 characters from previous step" ([SQL-Truncated]... is 16 characters in length.)
insert this new string in that column instead, thereby ensuring we only get 50 chars.

You can try something like this: create a stored function
CREATE FUNCTION dbo.TrimLongerThan50(#Input NVARCHAR(500))
RETURNS NVARCHAR(50)
AS BEGIN
DECLARE #Result NVARCHAR(50)
SET #Result = #Input
IF LEN(#Input) > 50
SET #Result = N'[SQL-Truncated] ' + SUBSTRING(#input, 1, 34)
RETURN #result
END
and then use it in the computed column
ALTER TABLE dbo.YourTable
ADD NewComputedColumn AS dbo.TrimLongerThan50(YourInputColumn)

the formula isn't that complicated but i'm not quite sure if you really want to create a computed column.
alter table add mytruncatedtext
as ( case when len(origcolumn) > 50
then N'[SQL-Truncated] ' + left(origcolumn, 34)
else origcolumn
end )
persisted

Related

Split comma delimited parameter being passed to stored procedure in SQL Server 2008 R2

I am being passed the following parameter to my stored procedure -
#AddOns = 23:2,33:1,13:5
I need to split the string by the commas using this -
SET #Addons = #Addons + ','
set #pos = 0
set #len - 0
While CHARINDEX(',', #Addons, #pos+1)>0
Begin
SET #len = CHARINDEX(','), #Addons, #pos+1) - #pos
SET #value = SUBSTRING(#Addons, #pos, #len)
So now #value = 23:2 and I need to get 23 which is my ID and 2 which is my quantity. Here is the rest of my code -
INSERT INTO TABLE(ID, Qty)
VALUES(#ID, #QTY)
set #pos = CHARINDEX(',', #Addons, #pos+#len) + 1
END
So what is the best way to get the values of 23 and 2 in separate fields to us in the INSERT statement?
First you would split the sets of key-value pairs into rows (and it looks like you already got that far), and then you get the position of the colon and use that to do two SUBSTRING operations to split the key and value apart.
Also, this can be done much more efficiently than storing each row's key and value into separate variables just to get inserted into a table. If you INSERT from the SELECT that breaks this data apart, it will be a set-based operation instead of row-by-row.
For example:
DECLARE #AddOns VARCHAR(1000) = N'23:2,33:1,13:5,999:45';
;WITH pairs AS
(
SELECT [SplitVal] AS [Value], CHARINDEX(N':', [SplitVal]) AS [ColonIndex]
FROM SQL#.String_Split(#AddOns, N',', 1) -- https://SQLsharp.com/
)
SELECT *,
SUBSTRING(pairs.[Value], 1, pairs.[ColonIndex] - 1) AS [ID],
SUBSTRING(pairs.[Value], pairs.[ColonIndex] + 1, 1000) AS [QTY]
FROM pairs;
/*
Value ColonIndex ID QTY
23:2 3 23 2
33:1 3 33 1
13:5 3 13 5
999:45 4 999 45
*/
GO
For that example I am using a SQLCLR string splitter found in the SQL# library (that I am the author of), which is available in the Free version. You can use whatever splitter you like, including the built-in STRING_SPLIT that was introduced in SQL Server 2016.
It would be used as follows:
DECLARE #AddOns VARCHAR(1000) = N'23:2,33:1,13:5,999:45';
;WITH pairs AS
(
SELECT [value] AS [Value], CHARINDEX(N':', [value]) AS [ColonIndex]
FROM STRING_SPLIT(#AddOns, N',') -- built-in function starting in SQL Server 2016
)
INSERT INTO dbo.TableName (ID, QTY)
SELECT SUBSTRING(pairs.[Value], 1, pairs.[ColonIndex] - 1) AS [ID],
SUBSTRING(pairs.[Value], pairs.[ColonIndex] + 1, 1000) AS [QTY]
FROM pairs;
Of course, the Full (i.e. paid) version of SQL# includes an additional splitter designed to handle key-value pairs. It's called String_SplitKeyValuePairs and works as follows:
DECLARE #AddOns VARCHAR(1000) = N'23:2,33:1,13:5,999:45';
SELECT *
FROM SQL#.String_SplitKeyValuePairs(#AddOns, N',', N':', 1, NULL, NULL, NULL);
/*
KeyID Key Value
1 23 2
2 33 1
3 13 5
4 999 45
*/
GO
So, it would be used as follows:
DECLARE #AddOns VARCHAR(1000) = N'23:2,33:1,13:5,999:45';
INSERT INTO dbo.[TableName] ([Key], [Value])
SELECT kvp.[Key], kvp.[Value]
FROM SQL#.String_SplitKeyValuePairs(#AddOns, N',', N':', 1, NULL, NULL, NULL) kvp;
Check out this blog post...
http://www.sqlservercentral.com/blogs/querying-microsoft-sql-server/2013/09/19/how-to-split-a-string-by-delimited-char-in-sql-server/
Noel
I am going to make another attempt at this inspired by the answer given by #gofr1 on this question...
How to insert bulk of column data to temp table?
That answer showed how to use an XML variable and the nodes method to split comma separated data and insert it into individual columns in a table. It seemed to me to be very similar to what you were trying to do here.
Check out this SQL. It certainly isn't has concise as just having "split" function, but it seems better than chopping up the string based on position of the colon.
Noel

Remove the 7th digit of a bigint for every row in a Sql Server table

I am maintaining SQL Server database and some c# code which uploads data to it from a third party. The database has a table 'LessonRoom' which contains a row for each lesson which occurs in a particluar room, it has a field 'SourceKey' which is a bigint and is formed by concatenating a room id and a lesson id, the c# which returns this key is as follows:
SourceKey = long.Parse(RoomId.ToString().PadRight(7, '0') + LessonId.ToString());
This code started falling over because the lessonId's grew too large and the resulting int is too large to fit in a bigint (c# long). The RoomIds are only ever 5 digits long so an easy fix is to PadRight(6, '0').
Now I have a solution but I need to update the existing data. I don't know how to remove a zero from the 7th digit of a SQL Server bigint in every row of 500,000 rows. Do I have to write a query to convert the value to a string, remove the zero, parse and put it back or can anyone think of a more succinct way to do it?
Essentially I need to turn this number:
6,159,800,830,114,069,893
Into this one:
615,980,830,114,069,893
Sine you know it is always the 7th character you want to remove you can do this quite easily.
declare #SourceKey bigint = 6159800830114069893
select cast(stuff(cast(#SourceKey as varchar(25)), 7, 1, '') as bigint)
you could resolve them with the modulo-Operator :)
here a simple T SQL example
DECLARE #input AS BIGINT
DECLARE #expect AS BIGINT
DECLARE #rest AS BIGINT
DECLARE #result AS BIGINT
DECLARE #resultShort AS BIGINT
SET #input = 6159800830114069893
SET #expect= 615980830114069893
SET #rest = #input % 1000000000000
SET #result = ( ( #input - #rest ) / 10 ) + #rest
SET #resultShort = ( ( #input - #input % 1000000000000 ) / 10 ) + #input %
1000000000000
SELECT #rest, #result,
CASE
WHEN #result = #expect THEN 'true'
ELSE 'false'
END AS test,
#resultShort,
CASE
WHEN #resultShort = #expect THEN 'true'
ELSE 'false'
END AS test2

Short guid in SQL Server / converting from a character string to uniqueidentifier

I need to create a column witch will contain short guid. So I found out something like this:
alter table [dbo].[Table]
add InC UNIQUEIDENTIFIER not null default LEFT(NEWID(),6)
But I get the error:
Conversion failed when converting from a character string to uniqueidentifier.
I've been trying
LEFT(CONVERT(varchar(36),NEWID()),6)
and
CONVERT(UNIQUEIDENTIFIER,LEFT(CONVERT(varchar(36),NEWID()),6))
But I am still getting the same error.
There is no such thing as "short guid". Guid, or uniqueidentifier is a 16 byte data type. You can read about it in MSDN. It means that the length must always be 16 bytes and you cannot use 6 characters as you are trying to do.
In the same MSDN article you can find description how you can initialize this type:
A column or local variable of uniqueidentifier data type can be
initialized to a value in the following ways:
By using the NEWID function.
By converting from a string constant in the form xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, in which each x is a
hexadecimal digit in the range 0-9 or a-f. For example,
6F9619FF-8B86-D011-B42D-00C04FC964FF is a valid uniqueidentifier
value.
In your case you are trying to convert only 6 characters to uniqueidentifier which obviously fails.
If you want to use just 6 characters, just use varchar(6):
alter table [dbo].[Table]
add InC varchar(6) not null default LEFT(NEWID(),6)
Keep in mind that in this case this guid is not guaranteed to be unique.
Using CRYPT_GEN_RANDOM instead of NEWID can improve random distribution of the string.
SELECT LEFT(CAST(CAST(CRYPT_GEN_RANDOM(16) AS UNIQUEIDENTIFIER) AS VARCHAR(50)), 6)
I just made this one since I couldn't find a good answer on the internet.
Please keep in mind this is a 64 bit representation of a 128bit value, so it has twice the collision possibilities that a real GUID would have. Does not handle 0.
Function takes a NEWID value: 6A10A273-4561-40D8-8D36-4D3B37E4A19C
and shortens it to : 7341xIlZseT
DECLARE #myid uniqueidentifier= NEWID()
select #myid
DECLARE #bigintdata BIGINT = cast(cast(reverse(NEWID()) as varbinary(max)) as bigint)
DECLARE #charSet VARCHAR(70) = '1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
DECLARE #cBase int = LEN(#charSet)
DECLARE #sUID varchar(22) = ''
DECLARE #x int
WHILE (#bigintdata <> 0)
BEGIN
SET #x = CAST(#bigintdata % #cBase as INT) + 1
SET #bigintdata = #bigintdata / #cBase
SET #sUID = SUBSTRING(#charSet, #x, 1) + #sUID;
END
SELECT #sUID

how to check particular ID is present in string

I want to check if a ID is present or not in a set of multiple ID.
Example
if id 5 is present in multiple id list like '1,2,3,4,5'
use CHARINDEX to return the index of the searched value.
Declare #MyString varchar(50)
Set #MyString = '1,2,3,4,5'
IF CHARINDEX('5',ContactName) > 0
Begin
Print '5 Exists'
End
Else
Begin
Print '5 Does not exists'
End
select count(*) FROM table where id = '5';
If it returns more than 0 means it's present.
If you are talking about sql this query will work for you, if you get nothing it means searching id is not there in the list else there.
SELECT * FROM journal_pulses WHERE mood_credentials in (2,27)
SELECT column FROM table WHERE CHARINDEX(',5,',(',' + column + ',')) > 0
Fiddle
One good solution in this context could be to store the values with leading and trailing comma, as:
',1,2,3,4,5,'
So, even if you store one value, store it as:
',5,'
This will help you look for required value as:
SELECT column FROM table WHERE column like '%,5,%';
Or
SELECT column FROM table WHERE CHARINDEX(',5,',(',' + column + ',')) > 0
Also, using this solution you can uniquely identify different values, given that the string does not contain duplicate values.
So, it is easy to identify 5, 50 and 350 from:
',5,50,150,250,350,450,500,'
I am not sure if you can change how the values can be stored. Please read this answer in light of the context of the question - as a starting point and not as a copy-paste solution.
I have tried something like this
DECLARE #item VARCHAR(50)
SET #ExpressionToSearch = '23,12'
SET #item = '23'
SELECT COUNT(*) from dbo.Split(#ExpressionToSearch,',')
WHERE ',' + (#ExpressionToSearch) + ','
LIKE '%'+#item +'%'
This scenario will return output greater than 0

SQL Server : converting varchar to INT

I am stuck on converting a varchar column UserID to INT. I know, please don't ask why this UserID column was not created as INT initially, long story.
So I tried this, but it doesn't work. and give me an error:
select CAST(userID AS int) from audit
Error:
Conversion failed when converting the varchar value
'1581............................................................................................................................' to data type int.
I did select len(userID) from audit and it returns 128 characters, which are not spaces.
I tried to detect ASCII characters for those trailing after the ID number and ASCII value = 0.
I have also tried LTRIM, RTRIM, and replace char(0) with '', but does not work.
The only way it works when I tell the fixed number of character like this below, but UserID is not always 4 characters.
select CAST(LEFT(userID, 4) AS int) from audit
You could try updating the table to get rid of these characters:
UPDATE dbo.[audit]
SET UserID = REPLACE(UserID, CHAR(0), '')
WHERE CHARINDEX(CHAR(0), UserID) > 0;
But then you'll also need to fix whatever is putting this bad data into the table in the first place. In the meantime perhaps try:
SELECT CONVERT(INT, REPLACE(UserID, CHAR(0), ''))
FROM dbo.[audit];
But that is not a long term solution. Fix the data (and the data type while you're at it). If you can't fix the data type immediately, then you can quickly find the culprit by adding a check constraint:
ALTER TABLE dbo.[audit]
ADD CONSTRAINT do_not_allow_stupid_data
CHECK (CHARINDEX(CHAR(0), UserID) = 0);
EDIT
Ok, so that is definitely a 4-digit integer followed by six instances of CHAR(0). And the workaround I posted definitely works for me:
DECLARE #foo TABLE(UserID VARCHAR(32));
INSERT #foo SELECT 0x31353831000000000000;
-- this succeeds:
SELECT CONVERT(INT, REPLACE(UserID, CHAR(0), '')) FROM #foo;
-- this fails:
SELECT CONVERT(INT, UserID) FROM #foo;
Please confirm that this code on its own (well, the first SELECT, anyway) works for you. If it does then the error you are getting is from a different non-numeric character in a different row (and if it doesn't then perhaps you have a build where a particular bug hasn't been fixed). To try and narrow it down you can take random values from the following query and then loop through the characters:
SELECT UserID, CONVERT(VARBINARY(32), UserID)
FROM dbo.[audit]
WHERE UserID LIKE '%[^0-9]%';
So take a random row, and then paste the output into a query like this:
DECLARE #x VARCHAR(32), #i INT;
SET #x = CONVERT(VARCHAR(32), 0x...); -- paste the value here
SET #i = 1;
WHILE #i <= LEN(#x)
BEGIN
PRINT RTRIM(#i) + ' = ' + RTRIM(ASCII(SUBSTRING(#x, #i, 1)))
SET #i = #i + 1;
END
This may take some trial and error before you encounter a row that fails for some other reason than CHAR(0) - since you can't really filter out the rows that contain CHAR(0) because they could contain CHAR(0) and CHAR(something else). For all we know you have values in the table like:
SELECT '15' + CHAR(9) + '23' + CHAR(0);
...which also can't be converted to an integer, whether you've replaced CHAR(0) or not.
I know you don't want to hear it, but I am really glad this is painful for people, because now they have more war stories to push back when people make very poor decisions about data types.
This question has got 91,000 views so perhaps many people are looking for a more generic solution to the issue in the title "error converting varchar to INT"
If you are on SQL Server 2012+ one way of handling this invalid data is to use TRY_CAST
SELECT TRY_CAST (userID AS INT)
FROM audit
On previous versions you could use
SELECT CASE
WHEN ISNUMERIC(RTRIM(userID) + '.0e0') = 1
AND LEN(userID) <= 11
THEN CAST(userID AS INT)
END
FROM audit
Both return NULL if the value cannot be cast.
In the specific case that you have in your question with known bad values I would use the following however.
CAST(REPLACE(userID COLLATE Latin1_General_Bin, CHAR(0),'') AS INT)
Trying to replace the null character is often problematic except if using a binary collation.
This is more for someone Searching for a result, than the original post-er. This worked for me...
declare #value varchar(max) = 'sad';
select sum(cast(iif(isnumeric(#value) = 1, #value, 0) as bigint));
returns 0
declare #value varchar(max) = '3';
select sum(cast(iif(isnumeric(#value) = 1, #value, 0) as bigint));
returns 3
I would try triming the number to see what you get:
select len(rtrim(ltrim(userid))) from audit
if that return the correct value then just do:
select convert(int, rtrim(ltrim(userid))) from audit
if that doesn't return the correct value then I would do a replace to remove the empty space:
select convert(int, replace(userid, char(0), '')) from audit
This is how I solved the problem in my case:
First of all I made sure the column I need to convert to integer doesn't contain any spaces:
update data set col1 = TRIM(col1)
I also checked whether the column only contains numeric digits.
You can check it by:
select * from data where col1 like '%[^0-9]%' order by col1
If any nonnumeric values are present, you can save them to another table and remove them from the table you are working on.
select * into nonnumeric_data from data where col1 like '%[^0-9]%'
delete from data where col1 like '%[^0-9]%'
Problems with my data were the cases above. So after fixing them, I created a bigint variable and set the values of the varchar column to the integer column I created.
alter table data add int_col1 bigint
update data set int_col1 = CAST(col1 AS VARCHAR)
This worked for me, hope you find it useful as well.

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