Remove leading zeros - sql

Given data in a column which look like this:
00001 00
00026 00
I need to use SQL to remove anything after the space and all leading zeros from the values so that the final output will be:
1
26
How can I best do this?
Btw I'm using DB2

This was tested on DB2 for Linux/Unix/Windows and z/OS.
You can use the LOCATE() function in DB2 to find the character position of the first space in a string, and then send that to SUBSTR() as the end location (minus one) to get only the first number of the string. Casting to INT will get rid of the leading zeros, but if you need it in string form, you can CAST again to CHAR.
SELECT CAST(SUBSTR(col, 1, LOCATE(' ', col) - 1) AS INT)
FROM tab

In DB2 (Express-C 9.7.5) you can use the SQL standard TRIM() function:
db2 => CREATE TABLE tbl (vc VARCHAR(64))
DB20000I The SQL command completed successfully.
db2 => INSERT INTO tbl (vc) VALUES ('00001 00'), ('00026 00')
DB20000I The SQL command completed successfully.
db2 => SELECT TRIM(TRIM('0' FROM vc)) AS trimmed FROM tbl
TRIMMED
----------------------------------------------------------------
1
26
2 record(s) selected.
The inner TRIM() removes leading and trailing zero characters, while the outer trim removes spaces.

This worked for me on the AS400 DB2.
The "L" stands for Leading.
You can also use "T" for Trailing.

I am assuming the field type is currently VARCHAR, do you need to store things other than INTs?
If the field type was INT, they would be removed automatically.
Alternatively, to select the values:
SELECT (CAST(CAST Col1 AS int) AS varchar) AS Col1

I found this thread for some reason and find it odd that no one actually answered the question. It seems that the goal is to return a left adjusted field:
SELECT
TRIM(L '0' FROM SUBSTR(trim(col) || ' ',1,LOCATE(' ',trim(col) || ' ') - 1))
FROM tab

One option is implicit casting: SELECT SUBSTR(column, 1, 5) + 0 AS column_as_number ...
That assumes that the structure is nnnnn nn, ie exactly 5 characters, a space and two more characters.
Explicit casting, ie SUBSTR(column,1,5)::INT is also a possibility, but exact syntax depends on the RDBMS in question.

Use the following to achieve this when the space location is variable, or even when it's fixed and you want to make a more robust query (in case it moves later):
SELECT CAST(SUBSTR(LTRIM('00123 45'), 1, CASE WHEN LOCATE(' ', LTRIM('00123 45')) <= 1 THEN LEN('00123 45') ELSE LOCATE(' ', LTRIM('00123 45')) - 1 END) AS BIGINT)
If you know the column will always contain a blank space after the start:
SELECT CAST(LOCATE(LTRIM('00123 45'), 1, LOCATE(' ', LTRIM('00123 45')) - 1) AS BIGINT)
both of these result in:
123
so your query would
SELECT CAST(SUBSTR(LTRIM(myCol1), 1, CASE WHEN LOCATE(' ', LTRIM(myCol1)) <= 1 THEN LEN(myCol1) ELSE LOCATE(' ', LTRIM(myCol1)) - 1 END) AS BIGINT)
FROM myTable1
This removes any content after the first space character (ignoring leading spaces), and then converts the remainder to a 64bit integer which will then remove all leading zeroes.
If you want to keep all the numbers and just remove the leading zeroes and any spaces you can use:
SELECT CAST(REPLACE('00123 45', ' ', '') AS BIGINT)
While my answer might seem quite verbose compared to simply SELECT CAST(SUBSTR(myCol1, 1, 5) AS BIGINT) FROM myTable1 but it allows for the space character to not always be there, situations where the myCol1 value is not of the form nnnnn nn if the string is nn nn then the convert to int will fail.
Remember to be careful if you use the TRIM function to remove the leading zeroes, and actually in all situations you will need to test your code with data like 00120 00 and see if it returns 12 instead of the correct value of 120.

Related

Can't remove Trailing spaces in the rows

I have column with data like:
'2020193'
'3208391'
'1038291'
'9349203'
The data type is varchar and I can't change it to int (data managed in this datatype always).
I have some rows with trailing spaces like:
' 2222928'
' 3213331'
I need to remove that trailing space from start. I have tried SUBSTRING() or TRIM()/RTRIM()/LTRIM(), but didn't worked any of those.
select (rtrim(ltrim(doc_id))) from bpm.sales where len(doc_id) = 8
select left(doc_id,2) from bpm.sales where len(doc_id) = 8
select charindex(' ',doc_id) from bpm.sales where len(doc_id) = 8
Also, when I am trying to search the data like:
select doc_id from bpm.sales where doc_id = ' 2269203'
I am geting nothing where it exist in the column. With CHARINDEX() I got 0.
Can someone explain me this behaviour and suggest a solution?
You can get rid of everything up to the first character you do want:
select stuff(doc_id, 1, patindex('%[^0-9a-zA-Z]%', doc_id) - 1, '')

SQL - How to remove a space character from a string

I have a table where the max length of a column (varchar) is 12, someone has loaded some value with a space, so rather than 'SPACE' it's 'SPACE '
I want to remove the space using a script, I was positive RTRIM or REPLACE(myValue, ' ', '') would work but LEN(myValue) shows there is still and extra character?
As mentioned by a couple folks, it may not be a space. Grab a copy of ngrams8k and you use it to identify the issue. For example, here we have the text, " SPACE" with a preceding space and trailing CHAR(160) (HTML BR tag). CHAR(160) looks like a space in SSMS but isn't "trimable". For example consider this query:
DECLARE #string VARCHAR(100) = ' SPACE'+CHAR(160);
SELECT '"'+#string+'"'
Using ngrams8k you could do this:
DECLARE #string VARCHAR(100) = ' SPACE'+CHAR(160);
SELECT
ng.position,
ng.token,
asciival = ASCII(ng.token)
FROM dbo.ngrams8k(#string,1) AS ng;
Returns:
position token asciival
---------- ------- -----------
1 32
2 S 83
3 P 80
4 A 65
5 C 67
6 E 69
7   160
As you can see, the first character (position 1) is CHAR(32), that's a space. The last character (postion 7) is not a space.
Knowing that CHAR(160) is the issue you could fix it like so:
SET #string = REPLACE(LTRIM(#string),CHAR(160),'')
If you are using SQL Server 2017+ you can also use TRIM which does a whole lot more than just LTRIM-and-RTRIM-ing. For example, this will remove
leading and trailing tabs, spaces, carriage returns, line returns and HTML BR tags.
SET #string = SELECT TRIM(CHAR(32)+CHAR(9)+CHAR(10)+CHAR(13)+CHAR(160) FROM #string)
Odds are it is some other non-printing character, carriage return is a big one when going from between *nix and other OS. One way to tell is to use the DUMP function. So you could start with a query like:
SELECT dump(column_name)
FROM your_table
WHERE column_name LIKE 'SPACE%'
That should help you find the offending character, however, that doesn't fix your problem. Instead, I would use something like REGEXP_REPLACE:
SELECT REGEXP_REPLACE(column_name, '[^A-z]')
FROM your_table
That should take care of any non-printing characters. You may need to play with the regular expression if you expect numbers or symbols in your string. You could switch to a character class like:
SELECT REGEXP_REPLACE(column_name, '[:cntrl:]')
FROM your_table

Allow leading zeros in a LIKE statement

I have a SQL query which includes the line:
WHERE
[TraceableItem].[IdentificationNo] LIKE N'015933%'
I would like this to match the following numbers:
015933
00015933
000000000015933
But not allow any non-zero characters. How could I do this?
--Some test data
DECLARE #sample TABLE
(
number_as_string VARCHAR(20)
)
INSERT INTO #sample
VALUES
('015933') -- okay
,('00015933') -- okay
,('000000000015933')-- okay
,(' 00015933') -- dont return as this doesnt start with a 0
,('25') -- dont return wrong number
,('string') -- dont return as its a string
,('st15933') -- dont return as it starts with a string.
,('001000015933') -- dont return as this is the number 1000015933
SELECT
*
FROM
#sample as s
WHERE
--only consider rows that are a number
--stops CONVERT exception being thrown on lines that do no convert
ISNUMERIC(s.number_as_string) = 1
AND
--Convert to INT wipes out the leading 0's, but also spaces
CONVERT(INT,s.number_as_string) LIKE '15933%'
AND
--must start with a number, i.e. check it doesn't start with a space.
--LEFT(s.number_as_string,1) NOT LIKE '[^0-9]'
--This version is easier to read as its not a double NOT logic like the version above
--Thanks to #Robert Kock
LEFT(s.number_as_string,1) BETWEEN '0' AND '9'
Gives the result
number_as_string
----------------
015933
00015933
000000000015933
You probably want to first convert to int and back to string as suggested by Neeraj Agarwal. But then take the left five characters and compare for exact equality to '15933'
where '15933' = left(convert(varchar(50),convert(int,
TraceableItem.IdentificationNo
)),5)
You can see it at work in the sample below, where it captures everything you desire and a little more, but doesn't capture the case presented by Harry Adams in the comments to Neeraj.
select *
from (values
('015933'),
('00015933'),
('000000000015933'),
('0001593399'),
('15933'),
('001000015933')
) vals (v)
where '15933' = left(convert(varchar(50),convert(int, v)),5)
I don't like converting to a number for this purpose. But one method is to "trim" the leading zeros away. For an exact match:
where replace(ltrim(replace([TraceableItem].[IdentificationNo], '0', ' ')), ' ', '0') = '15933'
For LIKE:
where replace(ltrim(replace([TraceableItem].[IdentificationNo], '0', ' ')), ' ', '0') LIKE '15933%'
You can also express this with LIKE/NOT LIKE:
where TraceableItem].[IdentificationNo] like '%15933%' and
TraceableItem].[IdentificationNo] not like '%[^0]%15933%'
You can use cast to convert to an int and back to a character string provided the string consists of digits only, e.g.:
select cast(cast("00015933" as int) as varchar(24))

Convert the Numeric data type to varchar without trailing Zeros in sybase

How to Convert the SQL data type Numerci(15,2) to string(varchar data type) without adding the trailing zeros in sybase.
Example- in column abc below values are present-
0.025
0.02
NULL
0.025589
5.289
on running the query-
select STR(column,10,4) from table --- produces the results 0.025,0.0200
select CAST(column as CHAR(5)) from table -- produces the results as 0.0250 etc
I can not do it in presentation layer
Can someone please help with query.
Unfortunately Sybase ASE does not have any native support for regex's, nor any out-of-the-box functions for stripping trailing zeros.
An obvious (?) first attempt might consist of a looping construct to strip off the trailing zeros, though it'd probably be easier to reverse() the initial string, strip off leading zeros, then reverse() to get back to the original value. Unfortunately this is not exactly efficient and would need to be encapsulated in a user-defined function (which introduces an additional performance hit each time it's invoked) in order to use it in a query.
The next idea would be to convert the zeros into something that can be (relatively) easily stripped off the end of the string, and it just so happens that ASE does provide the rtrim() function for stripping trailing spaces. This idea would look something like:
convert all zeros to spaces [str_replace('string','0',' ')]
strip off trailing spaces [rtrim('string')]
convert any remaining spaces back to zeros [str_replace('string',' ','0')]
** This obviously assumes the original string does not contain any spaces.
Here's an example:
declare #mystring varchar(100)
select #mystring = '0.025000'
-- here's a breakdown of each step in the process ...
select ':'+ #mystring + ':' union all
select ':'+ str_replace(#mystring,'0',' ') + ':' union all
select ':'+ rtrim(str_replace(#mystring,'0',' ')) + ':' union all
select ':'+ str_replace(rtrim(str_replace(#mystring,'0',' ')),' ','0') + ':'
-- and the final solution sans the visual end markers (:)
select str_replace(rtrim(str_replace(#mystring,'0',' ')),' ','0')
go
----------
:0.025000:
: . 25 :
: . 25:
:0.025:
--------
0.025
If you need to use this code snippet quite often then you may want to consider wrapping it in a user-defined function, though keep in mind there will be a slight performance hit each time the function is called.
Following approaches can be used -
1) It uses the Replace function
select COLUMN,str_replace(rtrim(str_replace(
str_replace(rtrim(str_replace(cast(COLUMN as varchar(15)), '0', ' ')), ' ', '0')
, '.', ' ')), ' ', '.')
from TABLE
Output -
0.0252
0.0252
2) Using Regex-
select COLUMN ,str(COLUMN ,10,3),
reverse(substring( reverse(str(COLUMN ,10,3)), patindex('%[^0]%',reverse(str(COLUMN ,10,3))), 10))
from TABLE
Output -
0.0252
0.0252.

Get all characters before space in MySQL

I would like to get all the characters in a field before a space
For example, if field1 is "chara ters"
I want it to return "chara"
What would this select statement look like?
SELECT LEFT(field1,LOCATE(' ',field1) - 1)
Note that if the string in question contains no spaces, this will return an empty string.
Below is another method that works and may seem a bit simpler to some. It uses the SUBSTRING_INDEX MySQL function. A 1 returns everything before the first space, and a -1 returns everything after the last space.
This returns 'chara':
SELECT SUBSTRING_INDEX( field1, ' ', 1 )
This returns 'ters':
SELECT SUBSTRING_INDEX( field1, ' ', -1 )
Details
A positive value will look for your specified character from the start of the string, and a negative value will start from the end of the string. The value of the number indicates the quantity of your specified character to look for before returning the remaining piece of the string. If the character you are searching for does not exist, the entire field value will be returned.
In this case, a -2 would return everything to the right of the second to last space, which doesn't exist in this example, so the entire field value will be returned.
You would need some string operations for that. Assuming every field has at least one space character:
SELECT SUBSTR(field1, 0, LOCATE(' ', field1)) FROM your_table;
Safe approach:
SELECT IF(
LOCATE(' ', field1),
SUBSTR(field1, 0, LOCATE(' ', field1)),
field1
) FROM your_table;
For a generalized approach that returns the nth value (one-based index) from a column containing delimited values:
select SUBSTRING_INDEX(SUBSTRING_INDEX(my_column,#delimiter,#index),#delimiter,-1) from my_table;
This will return the entire column contents if the delimiter does not exist, and the last field if the index value exceeds the number of fields.
For instance, if my_column contains 'foo bar baz' and you want the 2nd field:
select SUBSTRING_INDEX(SUBSTRING_INDEX(my_column,' ',2),' ',-1) from my_table;
will return bar, and if you specify the 4th field (which does not exist):
select SUBSTRING_INDEX(SUBSTRING_INDEX(my_column,' ',4),' ',-1) from my_table;
will return baz (the last field).