MySQL Natural Language Fulltext Search

MySQL’s Natural Language Full-Text Search is a feature that allows you to perform full-text searches with a focus on natural language. It takes into consideration the relevance of words and their occurrence in the search text. This is particularly useful for searching text data such as articles, blog posts, and product descriptions. To use Natural Language Full-Text Search in MySQL:

1. Creating a Full-Text Index:

Before performing Natural Language Full-Text Searches, you need to create a full-text index on the columns you want to search within. You can do this as follows:

ALTER TABLE your_table ADD FULLTEXT your_fulltext_index (column1, column2, ...);

Replace your_table with your table name and column1, column2, etc. with the names of the columns you want to index.

2. Performing Natural Language Full-Text Searches:

You can perform Natural Language Full-Text Searches using the MATCH() function along with the AGAINST() function:

SELECT * FROM your_table WHERE MATCH(column1, column2) AGAINST('search_term');

Replace your_table with your table name, column1, column2, etc. with the indexed columns, and 'search_term' with the term you want to search for.

3. Ranking and Relevance:

The Natural Language Full-Text Search returns results with a relevance score, indicating how well the search term matches the text. By default, rows are sorted by descending relevance.

4. Modifiers for Natural Language Search:

MySQL supports modifiers that affect Natural Language Full-Text Searches:

• IN NATURAL LANGUAGE MODE: This is the default mode and works well for most natural language queries.
• IN NATURAL LANGUAGE MODE WITH QUERY EXPANSION: It broadens the search by including synonyms and similar words.

SELECT * FROM your_table WHERE MATCH(column) AGAINST('search_term' IN NATURAL LANGUAGE MODE WITH QUERY EXPANSION);

5. Stopwords and Minimum Word Length:

MySQL’s Natural Language Search might ignore common words (stopwords) and words with lengths below a certain threshold (minimum word length). You can configure these settings using MySQL’s configuration options (ft_stopword_file and ft_min_word_len).

Remember that the behavior of Natural Language Full-Text Search might vary slightly between MySQL versions, and MySQL has some limitations when it comes to complex search requirements. Always refer to the official MySQL documentation for the version you’re using for accurate information.