Using data within an extracted text string for an inner join - sql

Question

Newbie so please be easy on me.
I have a select statement which returns a text string
select [column name]from [table] where [column name] like '%dog%'
simple enough, returns a result much like below
random text dog '123' more random text
random text dog '345' more random text
random text dog '723' more random text ...
I am looking to extract the 123, 345, 723 part of the text string which I can kind of do through using
Declare #Text Varchar(100);
Set #Text = 'random text dog ''123'' more random text';
Select Left(Substring(#Text, Patindex('%''%', #Text) + 1, Len(#Text) - Patindex('%''%', #Text))
,Patindex('%''%', Substring(#Text, Patindex('%''%', #Text) + 1, Len(#Text) - Patindex('%''%', #Text)))- 1) 'Lookup Index'
I am then wanting to use the result as part of inner join to another table to return a result along the lines of
Lookup Index Colour
123 Blue
345 Green
723 Orange
I just cant seem to tie it all together so any help much appreciated.
Thanking you all in advance.

Answer 1

Here's an option for you.
Load the parsed data into a temp table, then join that back to your lookup table. I would be easier and would probably perform better.
Have a look at this. There's an example with some test data all using temp tables. You'd obviously need to adjust for your specific tables and requirements:
--This will be our table that has the data you want to parse
CREATE TABLE #TestData (
TextColumn nvarchar(1000)
)
--lookup table for colours
CREATE TABLE #LookUp(
LookUpIndex INT
,Colour NVARCHAR(100)
)
--Use a temp table to load the parsed data from #TestData
CREATE TABLE #TestDataParse (
LookUpIndex INT
,TextColumn NVARCHAR(1000)
)
--Load our test data
INSERT INTO [#TestData] ([TextColumn])
VALUES('random text dog ''123'' more random text')
,('random text dog ''345'' more random text')
,('random text dog ''723'' more random text')
--populate our lookup table
INSERT INTO [#LookUp] (
[LookUpIndex]
, [Colour]
)
VALUES(123, 'Blue')
,(345, 'Green')
,(723 , 'Orange')
--Now parse the LookUp number out and load that to our temp table
INSERT INTO [#TestDataParse] (
[LookUpIndex]
, [TextColumn]
)
SELECT
Left(Substring(TextColumn, Patindex('%''%', TextColumn) + 1, Len(TextColumn) - Patindex('%''%', TextColumn))
,Patindex('%''%', Substring(TextColumn, Patindex('%''%', TextColumn) + 1, Len(TextColumn) - Patindex('%''%', TextColumn)))- 1) AS LookUpIndex
,[TextColumn]
FROM [#TestData]
--Now we can join that back to the lookup table
SELECT *
FROM [#TestDataParse] [a]
INNER JOIN [#LookUp] [b]
ON [b].[LookUpIndex] = [a].[LookUpIndex];
--Example done
--Drop our #temp tables
DROP TABLE [#LookUp]
DROP TABLE [#TestData]
DROP TABLE [#TestDataParse]
or you could skip loading into a temp table and use a sub query to simplify the join back to your lookup table, something like:
SELECT * FROM (
SELECT
Left(Substring(TextColumn, Patindex('%''%', TextColumn) + 1, Len(TextColumn) - Patindex('%''%', TextColumn))
,Patindex('%''%', Substring(TextColumn, Patindex('%''%', TextColumn) + 1, Len(TextColumn) - Patindex('%''%', TextColumn)))- 1) AS LookUpIndex
,[TextColumn]
FROM [#TestData] a
) AS tb
INNER JOIN [#LookUp] b ON [b].[LookUpIndex] = [tb].[LookUpIndex]
I'd test each one and see which performs the best for you.

Answer 2

This is a pain but you can do:
select t.col, left(v.dogv, charindex('''', v.dogv) - 1)
from (values ('random text dog ''123'' more random text')) t(col) cross apply
(values (stuff(col, 1, charindex('dog', col) + 4, ''))
) v(dogv)
where col like '%dog%';