How to select specific row in SQL from a bad designed schema? - sql

Question

I have a string in a column of a db schema I did not design, like this:
numbers column
--------------------
First: 1,2,33,34,43,5
Second: 1,2,3,4,5
Despite I know this is not the best practice scenario, I would still want to select the row which contains only '3' value, not '33' or '34' or '43'.
How could I select only second row?
SELECT *
FROM tblNumbers
WHERE numbers like '%,3,%' OR numbers like '3,%' OR numbers like '%,3'
This query selected both 2 columns. How can I do this, to get just the second row?
Here is my problem:
Thanks.

Answer 1

You should be storing the values in a separate table, with one row per column and per number.
Sometimes, though, we are stuck with other peoples bad data structures. If so, you can do what you want in this rather cumbersome way:
where replace(replace(numbers, '{', ','), '}', ',') like '%,3,%'
That is, put the delimiters around all the numbers in numbers.
Let me repeat, though: the proper way to store this data is using a separate table. If you need to store multiple values in a column like this, then do some research on XML and JSON formats (which are supported only in the most recent version of SQL Server).
EDIT:
Exactly the same idea applies, the code is just simpler:
where ',' + numbers + ',' like '%,3,%'

Answer 2

Did you try it like this?
SELECT *
FROM tblNumbers
WHERE number = '3' OR ReportedGMY = '3'

Answer 3

if you are storing numbers as integers
SELECT *
FROM tblNumbers
WHERE number = '3'
if you are storing as string
SELECT *
FROM tblNumbers
WHERE number like "3"

Answer 4

Its is bad practice to save command separated value in a column. This should be avoid as much as possible. If you really need to do it, then can be done using user defined function.
CREATE FUNCTION dbo.HasDigit (#String VARCHAR(MAX), #DigitToCheck INT, #Delimiter VARCHAR(10))
RETURNS BIT
AS
BEGIN
DECLARE #DelimiterPosition INT
DECLARE #Digit INT
DECLARE #ContainsDigit BIT = 0
WHILE CHARINDEX(#Delimiter, #String) > 0
BEGIN
SELECT #DelimiterPosition = CHARINDEX(#Delimiter, #String)
SELECT #Digit = CAST(SUBSTRING(#String, 1, #DelimiterPosition - 1) AS INT)
IF(#Digit = #DigitToCheck)
BEGIN
SET #ContainsDigit = 1
END
SELECT #String = SUBSTRING(#String, #DelimiterPosition + 1, LEN(#String) - #DelimiterPosition)
END
RETURN #ContainsDigit
END;
GO
CREATE TABLE TEST (
Numbers VARCHAR(MAX),
COLUMNNAME VARCHAR(MAX)
)
GO
INSERT INTO TEST VALUES('First:', '1,2,33,34,43,5')
INSERT INTO TEST VALUES('Second:', ' 1,2,3,4,5')
GO
SELECT * FROM TEST WHERE dbo.HasDigit(COLUMNNAME, 3, ',') = 1
Output:
--Numbers COLUMNNAME
--------- ----------------
--Second: 1,2,3,4,5