Mysql Like multiple values

sql

join

performance

best-practices

byNikita Barsukov·Aug 24, 2024

To find rows with several different string values in a column, use MySQL's REGEXP:

SELECT * FROM your_table WHERE your_column REGEXP 'string1|string2|string3';

This fetches rows where your_column contains 'string1', 'string2', or 'string3'. This is more efficient compared to chaining numerous LIKE operators with OR.

To achieve more optimized queries and improved application performance, understanding the trade-offs and efficiencies between LIKE and REGEXP is crucial.

Using `LIKE` vs `REGEXP`: The Trade-offs

When querying data, you'll encounter cases that require searching for multiple patterns in a column. In such cases, you have two options: LIKE and REGEXP. Let's dive deeper:

When to Use `LIKE`?

LIKE is straightforward and perfect for simple pattern matching. It's great you're matching a specific, invariable pattern:

SELECT * FROM users WHERE username LIKE '%JohnDoe%' OR username LIKE '%JDoe%';

Remember, wildcards (%) overuse can lead to full table scans—performance killer.

`REGEXP`: A More Robust Tool for Complex Patterns

For handling more complex patterns, REGEXP offer advanced capabilities:

SELECT * FROM users WHERE username REGEXP 'JohnDoe|JDoe';

With REGEXP, multi-pattern checks can be condensed into a single concise statement.

Evaluating The Efficiency

LIKE is perfect for single, simple patterns, whereas REGEXP is useful for multi-pattern searches – avoiding the need for multiple LIKE clauses with OR.

Extra `REGEXP` Tips:

Make your RegExp case-insensitive with the (?i) flag.
Match start and end of string with ^ and $.
Define character ranges with [a-z] or [0-9].

Depending on your use case and the complexity of your searches, LIKE and REGEXP can both be your best friends.

Optimizing MySQL: Tips and Tricks

Performance Enhancement

Use Indexes: When using LIKE with known patterns, indexes improve performance.
Wildcards: %apple causes a slower search than 'apple%' because it doesn't benefit from index.
REGEXP Costs More: REGEXP involves more computer power than LIKE; avoid it for simple patterns

Common Pitfalls

Leading wildcard in LIKE on large datasets slows down searches, a no-go when you're in a hurry.
A simple LIKE can serve the same purpose as overly complicated REGEXP expressions, don't be unnecessarily fancy.
Full-text search is better suited for natural-language searches on large text fields, helps in saving time when going through mountains of text data.