SQL join multiple criteria - mysql

Question

I have a difficult task to build up an array retrieved from a table similar to the one below:
table_a
id | scenario_id | entity_id
1 1;2;3;4;5 1;3
2 4;5;8;10 2;3
3 1;5;8;11 1;2;4;
4 3;5;8;9 4;5;
Now, if one user selects from one entity_id, let's say 3, the SQL query should return something similiar to:
scenario_id
1;2;3;4;5;8;10
Or, if he selects 5, the returned array should look like:
scenario_id
3;5;8;9
Could that be done using only SQL statements?

Answer 1

For SQL Server you can use this to get desired output:
DECLARE #xml xml, #entity_id int = 3
--Here I generate data similar to yours
;WITH cte AS (
SELECT *
FROM (VALUES
(1, '1;2;3;4;5', '1;3'),
(2, '4;5;8;10', '2;3'),
(3, '1;5;8;11', '1;2;4;'),
(4, '3;5;8;9', '4;5;')
) as t(id, scenario_id, [entity_id])
)
--create xml
SELECT #xml = (
SELECT CAST('<i id="'+ CAST(id as nvarchar(10)) +'"><s>' + REPLACE(scenario_id,';','</s><s>') + '</s><e>' + REPLACE([entity_id],';','</e><e>') + '</e></i>' as xml)
FROM cte
FOR XML PATH('')
)
--Normalizing the table and getting result
SELECT STUFF((
SELECT ';' + CAST(scenario_id as nvarchar(10))
FROM (
SELECT DISTINCT t.v.value('.','int') as scenario_id
FROM #xml.nodes('/i/s') as t(v)
INNER JOIN #xml.nodes('/i/e') as s(r)
ON t.v.value('../#id','int') = s.r.value('../#id','int')
WHERE s.r.value('.','int') = #entity_id
) as p
FOR XML PATH('')),1,1,'') as scenario_id
Output for entity_id = 3:
scenario_id
1;2;3;4;5;8;10
For entity_id = 5
scenario_id
3;5;8;9

Answer 2

you can use something like this to find a id in the scenario_id, but its always a FULL TABLE scan.
SELECT *
FROM table_a
WHERE
FIND_IN_SET('3', REPLACE(scenario_id,';',',')) > 0;

Answer 3

Simple. NORMALISE your schema... At it's crudest, that might be as follows...
DROP TABLE IF EXISTS my_table;
CREATE TABLE my_table
(id INT NOT NULL
,scenario_id INT NOT NULL
,entity_id INT NOT NULL
,PRIMARY KEY (id,scenario_id,entity_id)
);
INSERT INTO my_table VALUES
(1, 1,1),
(1, 1,3),
(1, 2,1),
(1, 2,3),
(1, 3,1),
(1, 3,3),
(1, 4,1),
(1, 4,3),
(1, 5,1),
(1, 5,3),
(2, 4,2),
(2, 4,3),
(2, 5,2),
(2, 5,3),
(2, 8,2),
(2, 8,3),
(2,10,2),
(2,10,3),
(3, 1,1),
(3, 1,2),
(3, 1,4),
(3, 5,1),
(3, 5,2),
(3, 5,4),
(3, 8,1),
(3, 8,2),
(3, 8,4),
(3,11,1),
(3,11,2),
(3,11,4),
(4, 3,4),
(4, 3,5),
(4, 5,4),
(4, 5,5),
(4, 8,4),
(4, 8,5),
(4, 9,4),
(4, 9,5);
SELECT DISTINCT scenario_id FROM my_table WHERE entity_id = 3 ORDER BY scenario_id;
+-------------+
| scenario_id |
+-------------+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 8 |
| 10 |
+-------------+

Answer 4

split the scenario_id by ';' and copy to temporary table to use that for your query use instr and substring functions
this link may help you but you need a loop function to call your procedure as the ';' is repeated