SQL Query to parse numbers from name - sql

Question

The DBMS in this case is SQL Server 2012.
I need a SQL query that will grab just the numbers from a device name. I've got devices that follow a naming scheme that SHOULD look like this:
XXXnnnnn
or
XXXnnnnn-XX
Where X is a letter and n is a number which should be left padded with 0's where appropriate. However, not all of the names are properly padded in this way.
So, imagine you have a column that looks something like this:
Name
----
XXX01234
XXX222
XXX0390-A2
XXX00965-A1
I need an SQL query that will return results from this example column as follows.
Number
------
01234
00222
00390
00965
Anyone have any thoughts? I've tried things like casting the name first as a float and then as an int, but to be honest, I'm just not skilled enough with SQL yet to find the solution.
Any help is greatly appreciated!

Answer 1

SQL Server does not have great string parsing functions. For your particular example, I think a case statement might be the simplest approach:
select (case when number like '___[0-9][0-9][0-9][0-9][0-9]%'
then substring(number, 4, 5)
when number like '___[0-9][0-9][0-9][0-9]%'
then '0' + substring(number, 4, 4)
when number like '___[0-9][0-9][0-9]%'
then '00' + substring(number, 4)
when number like '___[0-9][0-9]%'
then '000' + substring(number, 4, 2)
when number like '___[0-9][0-9]%'
then '0000' + substring(number, 4, 1)
else '00000'
end) as EmbeddedNumber

Answer 2

This might work :
SELECT RIGHT('00000'
+ SUBSTRING(Col, 1, ISNULL(NULLIF((PATINDEX('%-%', Col)), 0) - 1, LEN(Col))), 5)
FROM (SELECT REPLACE(YourColumn, 'XXX', '') Col
FROM YourTable)t
SQLFIDDLE

Answer 3

This will work even when XXX can be of different len:
DECLARE #t TABLE ( n NVARCHAR(50) )
INSERT INTO #t
VALUES ( 'XXXXXXX01234' ),
( 'XX222' ),
( 'X0390-A2' ),
( 'XXXXXXX00965-A1' )
SELECT REPLICATE('0', 5 - LEN(n)) + n AS n
FROM ( SELECT SUBSTRING(n, PATINDEX('%[0-9]%', n),
CHARINDEX('-', n + '-') - PATINDEX('%[0-9]%', n)) AS n
FROM #t
) t
Output:
n
01234
00222
00390
00965

Answer 4

If the first 3 chars are always needed to be removed, then you can do something like that (will work if the characters will start only after '-' sign):
DECLARE #a AS TABLE ( a VARCHAR(100) );
INSERT INTO #a
VALUES
( 'XXX01234' ),
( 'XXX222' ),
( 'XXX0390-A2' ),
( 'XXX00965-A1' );
SELECT RIGHT('00000' + SUBSTRING(a, 4, CHARINDEX('-',a+'-')-4),5)
FROM #a
-- OUTPUT
01234
00222
00390
00965
Another option (will extract numbers after first 3 characters):
SELECT
RIGHT('00000' + LEFT(REPLACE(a, LEFT(a, 3), ''),
COALESCE(NULLIF(PATINDEX('%[^0-9]%',
REPLACE(a, LEFT(a, 3), '')),
0) - 1,
LEN(REPLACE(a, LEFT(a, 3), '')))), 5)
FROM
#a;
-- OUTPUT
01234
00222
00390
00965