SQLite 3 CROSS or INTERSECT complex Subqueries - sqlite

Question

I have 3 related tables. One table has the rows that I am actually looking for, another table has the Data that I need to be Searching and the Third table describes What data I am looking for. I am getting undesired results from the following query :
SELECT * FROM names WHERE namesKey IN ( SELECT namesKey FROM data WHERE
( dataType IS 3 AND data IS 'COINCIDENCE' )
AND ( dataType IS 2 AND data IS 'STATE' )
AND ( dataType IS 1 AND data IS 'COUNTRY' ) );
I need help making a query based on Multiple rows from the filter table. I need the rows which correspond to the keys from the second table that exist on multiple rows... I am explaining badly... here is an example :
DROP TABLE IF EXISTS names ;
CREATE TABLE names (
namesKey INTEGER PRIMARY KEY ASC,
name TEXT NOT NULL
);
DROP TABLE IF EXISTS data ;
CREATE TABLE data (
dataKey INTEGER PRIMARY KEY ASC,
namesKey INTEGER NOT NULL,
dataType INTEGER NOT NULL,
data TEXT NOT NULL,
FOREIGN KEY(namesKey) REFERENCES names(namesKey)
);
DROP TABLE IF EXISTS filter ;
CREATE TABLE filter (
filterKey INTEGER PRIMARY KEY ASC,
dataType INTEGER NOT NULL,
data TEXT NOT NULL
);
INSERT INTO names( name ) VALUES ( 'name1' );
INSERT INTO names( name ) VALUES ( 'name2' );
INSERT INTO names( name ) VALUES ( 'name3' );
INSERT INTO names( name ) VALUES ( 'name4' );
INSERT INTO names( name ) VALUES ( 'name5' );
INSERT INTO names( name ) VALUES ( 'name6' );
INSERT INTO names( name ) VALUES ( 'name7' );
INSERT INTO names( name ) VALUES ( 'name8' );
INSERT INTO names( name ) VALUES ( 'name9' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 1, 1, 'COUNTRY' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 1, 2, 'STATE' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 1, 3, 'CITY' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 2, 1, 'COUNTRY' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 2, 2, 'STATE' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 2, 3, 'OTHERCITY' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 3, 1, 'COUNTRY' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 3, 2, 'STATE' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 3, 3, 'COINCIDENCE' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 4, 1, 'COUNTRY' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 4, 2, 'OTHERSTATE' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 4, 3, 'COINCIDENCE' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 5, 1, 'OTHERCOUNTRY' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 5, 2, 'RANDOM' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 5, 3, 'COINCIDENCE' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 6, 1, 'OTHERCOUNTRY' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 6, 2, 'OTHERSTATE' );
INSERT INTO data( namesKey, dataType, data ) VALUES ( 6, 3, 'COINCIDENCE' );
INSERT INTO filter( dataType, data ) VALUES ( 1, 'COUNTRY' );
INSERT INTO filter( dataType, data ) VALUES ( 2, 'STATE' );
INSERT INTO filter( dataType, data ) VALUES ( 3, 'COINCIDENCE' );
Now what I need is to be able to run 3 different types of queries relatively reliably.
I need to search for "No Data" and get names 7, 8, and 9
This one is Easy :
SELECT * FROM names WHERE namesKey NOT IN ( SELECT namesKey FROM data ) ;
I need to Search based on a Single type of data from the data table
Also Easy, Desired Result 3, 4, 5, and 6
SELECT * FROM names WHERE
namesKey IN ( SELECT namesKey FROM data WHERE
( dataType IS 3 AND data IS 'COINCIDENCE' ) )
;
I need to Search based on Multiple rows From The filter table. This one I don't know how to do...
Desired Result is the name3 row ONLY
I Could do it by
SELECT * FROM names WHERE
namesKey IN ( SELECT namesKey FROM data WHERE
( dataType IS 3 AND data IS 'COINCIDENCE' ) )
AND
namesKey IN ( SELECT namesKey FROM data WHERE
( dataType IS 2 AND data IS 'STATE' ) )
AND
namesKey IN ( SELECT namesKey FROM data WHERE
( dataType IS 1 AND data IS 'COUNTRY' ) )
;
But that is just Ugly with a capital UGH!
And even worse with that approach, the dataType is theoretically arbitrarily large and thus I might end up trying to string together dozens or even Hundreds of sub queries... I could run out of RAM just composing my string before even Trying to put it into the SQL.
So I am looking for a more elegant solution. Any suggestions?

Answer 1

If I understand you correctly, you could use:
SELECT *
FROM names
WHERE namesKey IN (SELECT namesKey
FROM data
WHERE dataType IS 3 AND data IS 'COINCIDENCE'
INTERSECT
SELECT namesKey
FROM data
WHERE dataType IS 2 AND data IS 'STATE'
INTERSECT
SELECT namesKey
FROM data
WHERE dataType IS 1 AND data IS 'COUNTRY'
);
SqlFiddleDemo
Output:
╔═══════════╦═══════╗
║ namesKey ║ name ║
╠═══════════╬═══════╣
║ 3 ║ name3 ║
╚═══════════╩═══════╝
Or using aggregation:
SELECT *
FROM names
WHERE namesKey IN (SELECT namesKey
FROM data
GROUP BY namesKey
HAVING SUM(dataType IS 3 AND data IS 'COINCIDENCE') > 0
AND SUM(dataType IS 2 AND data IS 'STATE') > 0
AND SUM(dataType IS 1 AND data IS 'COUNTRY') > 0
)
SqlFiddleDemo2

Answer 2

You can join the filter table directly with the actual table to get rows with matches, and then check for only those name keys where all three search terms are matching, i.e., groups whose number of matching rows is the same as the number of all search values:
SELECT namesKey
FROM data
JOIN filter USING (dataType, data)
GROUP BY namesKey
HAVING COUNT(*) = (SELECT COUNT(*) FROM filter);
Then use these name keys as usual:
SELECT *
FROM names
WHERE namesKey IN (SELECT namesKey...);