SQL Puzzle | The Input Order Puzzle | SQL Interview Question

In this puzzle you have to get records based on the Input comma separated values. The challenge here is to get the records in the same order the input values are specified in the string. For more details please see the sample input and expected output.

Sample Input

Id Val
1 a
2 b
3 c
4 d
5 e

Expected Output

–OUTPUT for Declare @Input varchar(max)=’3,2′

Id Val
3 c
2 b

Script – DDL and INSERT Sample Data

 ```-- CREATE TABLE theOrder ( Id INT ,Val Varchar(10) ) GO INSERT INTO theOrder VALUES (1,'a'), (2,'b'), (3,'c'), (4,'d'), (5,'e') GO SELECT * FROM theOrder GO -- ```

SOLUTION – 1 | STRING_SPLIT

 ```-- Declare @Input varchar(max)='3,2' SELECT a.* FROM theOrder a INNER JOIN ( SELECT Value , Row_Number() OVER (ORDER BY (SELECT NULL)) rnk FROM STRING_SPLIT(@Input,',') )z ON z.value = a.Id ORDER BY z.rnk -- ```

OUTPUT – 1

 ```-- Id Val ----------- ---------- 3 c 2 b (2 rows affected) -- ```

SOLUTION – 2 | using XML

 ```-- Declare @Input varchar(max)='3,2' SELECT a.* FROM theOrder a INNER JOIN ( Select m.value('(./text())[1]', 'int') Vals ,Row_Number() OVER (ORDER BY (SELECT NULL)) rnk From ( VALUES (CAST('' + REPLACE(@Input,',','')+'' AS XML)) ) x(r) CROSS APPLY r.nodes('a') node(m) )z on a.id = z.Vals ORDER BY rnk -- ```

OUTPUT – 2

 ```-- Id Val ----------- ---------- 3 c 2 b (2 rows affected) -- ```

Enjoy 🙂

Pawan Khowal

Pawan is a SQL Server Developer. If you need any help in writing code/puzzle or training please email at – pawankkmr”AT”gmail.com. Meanwhile please go throgh the top pages from his blog.

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