search.sql

-- Function to split the input query and generate all contiguous combinations
CREATE FUNCTION split_to_table(@input_query VARCHAR(MAX))
RETURNS @result TABLE (combination VARCHAR(MAX))
AS
BEGIN
    DECLARE @words TABLE (id INT IDENTITY(1,1), word VARCHAR(255))
    DECLARE @total_words INT, @i INT, @j INT, @current_combination VARCHAR(MAX)

    -- Step 1: Splitting the input string into words
    INSERT INTO @words (word)
    SELECT value
    FROM STRING_SPLIT(@input_query, ' ') -- This function varies based on SQL dialect

    SELECT @total_words = COUNT(*) FROM @words

    -- Step 2: Generating all contiguous combinations
    SET @i = 1
    WHILE @i <= @total_words
    BEGIN
        SET @j = @i
        SET @current_combination = ''

        WHILE @j <= @total_words
        BEGIN
            SELECT @current_combination = @current_combination + ' ' + word
            FROM @words
            WHERE id = @j

            -- Insert the current combination into the result table
            INSERT INTO @result (combination)
            VALUES (LTRIM(@current_combination))

            SET @j = @j + 1
        END

        SET @i = @i + 1
    END

    RETURN
END

CREATE TABLE synonyms (
    term VARCHAR(255),
    longest_form VARCHAR(255)
);

CREATE TABLE abbreviations (
    abbreviation VARCHAR(255),
    full_form VARCHAR(255)
);

INSERT INTO synonyms (term, longest_form) VALUES 
('anca', 'antineutrophil cytoplasmic antibodies'),
('anca associated vasculitis', 'antineutrophil cytoplasmic antibodies associated vasculitis');

INSERT INTO abbreviations (abbreviation, full_form) VALUES 
('anca', 'antineutrophil cytoplasmic antibodies'),
('aav', 'anca associated vasculitis');

-- Assuming you have an input query
DECLARE @input_query VARCHAR(255);
SET @input_query = 'your input query here';

-- Step 1: Breaking down the input query
WITH split_terms AS (
    SELECT term
    FROM split_to_table(@input_query, ' ')
)

-- Step 2: Matching terms against synonyms
, expanded_terms AS (
    SELECT s.longest_form
    FROM split_terms st
    LEFT JOIN synonyms s ON st.term = s.term
)

-- Step 3: Apply expansion
, expanded_query AS (
    SELECT DISTINCT longest_form 
    FROM expanded_terms 
    ORDER BY LENGTH(longest_form) DESC
)

-- Step 4: Apply contraction
, contracted_query AS (
    SELECT DISTINCT a.abbreviation 
    FROM abbreviations a
    WHERE a.full_form IN (SELECT longest_form FROM expanded_terms)
    ORDER BY LENGTH(a.full_form) DESC
)

-- Step 5: Nested contraction
, nested_contracted_query AS (
    SELECT DISTINCT a.abbreviation 
    FROM abbreviations a
    WHERE a.full_form IN (
        SELECT abbreviation FROM abbreviations WHERE full_form IN (
            SELECT longest_form FROM expanded_terms
        )
    )
    ORDER BY LENGTH(a.full_form) DESC
)

-- Step 6: Final Combined Query
WITH (SELECT * FROM expanded_query
UNION
SELECT * FROM contracted_query
UNION
SELECT * FROM nested_contracted_query) as search_queries;

-- Step 7: Query Documents
CREATE VIRTUAL TABLE documents USING fts5(title, body);
INSERT INTO documents (title, body) VALUES ('Example Title', 'Example body text');

SELECT * FROM documents
WHERE documents MATCH (group_concat(search_queries, ' OR '));