Add a rownumber based on the sequence of values provided - sql

Question

SELECT Code, Value FROM dbo.Sample
Output:
Code Value
Alpha Pig
Beta Horse
Charlie Dog
Delta Cat
Echo Fish
I want to add a sequence column by specifying a list of Codes and sort the list based on the order specified in the IN clause.
SELECT Code, Value FROM dbo.Sample
WHERE Code in ('Beta', 'Echo', 'Alpha')
I could declare a variable at the top to specify the Codes if that is easier.
The key is that I want to add the row number based on the order that I specify them in.
Output:
Row Code Value
1 Beta Horse
2 Echo Fish
3 Alpha Pig
Edit: I realized after that my Codes are all a fixed length which makes a big difference in how it could be done. I marked the answer below as correct, but my solution is to use a comma-separated string of values:
DECLARE #CodeList TABLE (Seq int, Code nchar(3))
DECLARE #CodeSequence varchar(255)
DECLARE #ThisCode char(3)
DECLARE #Codes int
SET #Codes = 0
-- string of comma-separated codes
SET #CodeSequence = 'ZZZ,ABC,FGH,YYY,BBB,CCC'
----loop through and create index and populate #CodeList
WHILE #Codes*4 < LEN(#CodeSequence)
BEGIN
SET #ThisCode = SUBSTRING(#CodeSequence,#Codes*4+1,3)
SET #Codes = #Codes + 1
INSERT #CodeList (Seq, Code) VALUES (#Codes, #ThisCode)
END
SELECT Seq, Code from #CodeList

Answer 1

Here are the only 2 ways I've seen work accurately:
The first uses CHARINDEX (similar to Gordon's, but I think the WHERE statement is more accurate using IN):
SELECT *
FROM Sample
WHERE Code IN ('Beta','Echo','Alpha')
ORDER BY CHARINDEX(Code+',','Beta,Echo,Alpha,')
Concatenating the comma with code should ensure sub-matches don't affect the results.
Alternatively, you could use a CASE statement:
SELECT *
FROM Sample
WHERE Code in ('Beta','Echo','Alpha')
ORDER BY CASE
WHEN Code = 'Beta' THEN 1
WHEN Code = 'Echo' THEN 2
WHEN Code = 'Alpha' THEN 3
END
SQL Fiddle Demo
Updated Demo with sub-matches.

Answer 2

Also you can use Values as Table Source
SELECT Row, Code, Value
FROM [Sample] s JOIN (
SELECT ROW_NUMBER() OVER(ORDER BY(SELECT 1)) AS Row, Match
FROM (VALUES ('Beta'),
('Echo'),
('Alpha'))
x (Match)
) o ON s.Code = o.Match
ORDER BY Row
Demo on SQLFiddle

Answer 3

Here is solution for any lenght code list.
Create table with self incrementing field and code. Insert in given order. Join tables and order by ...
Some details. Please read this. You will find there function that creates table with auto increment field from string (delimited by commas), i.e.
mysql> call insertEngineer('dinusha,nuwan,nirosh');
Query OK, 1 row affected (0.12 sec)
mysql> select * from engineer;
+----+----------+
| ID | NAME |
+----+----------+
| 1 | dinusha |
| 2 | nuwan |
| 3 | nirosh |
+----+----------+
Next join your Sample table with result of above. GL

Answer 4

Just a lil bit of change to whats been done above to include the rownumbers as well.
SELECT CASE
WHEN Code = 'BetaBeta' THEN 1
WHEN Code = 'Beta' THEN 2
WHEN Code = 'Alpha' THEN 3
END CodeOrder,
*
FROM Sample
WHERE Code in ('BetaBeta','Beta','Alpha')
ORDER BY CodeOrder
SQL Fiddle Demo

Answer 5

I might be tempted to do this using string functions:
declare #list varchar(8000) = 'Beta,Echo,Alpha';
with Sample as (
select 'Alpha' as Code, 'Pig' as Value union all
select 'Beta', 'Horse' union all
select 'Charlie', 'Dog' union all
select 'Delta', 'Cat' union all
select 'Echo', 'Fish'
)
select * from Sample
where charindex(Code, #list) > 0
order by charindex(Code, #list)
If you are worried about submatches, just do the "delimiter" trick:
where #list like '%,'+Code+',%'