How to Perform Multi-Table Keyword Searches in PHP and MySQL?

Performing Multi-Table Keyword Searches in PHP and MySQL

Introduction:

When working with multiple tables in a MySQL database, searching for a specific keyword across those tables can become challenging. This article addresses this issue by providing a comprehensive solution in PHP.

Multi-Table Search Using LIKE:

To perform a multi-table search using the LIKE operator, you can utilize the UNION operator to combine multiple queries. Each query targets a specific table (in this case, 'messages,' 'topics,' and 'comments') and searches within the 'content' and 'title' fields.

$query = "(SELECT content, title, 'msg' as type FROM messages WHERE content LIKE '%" . $keyword . "%' OR title LIKE '%" . $keyword ."%')
UNION
(SELECT content, title, 'topic' as type FROM topics WHERE content LIKE '%" . $keyword . "%' OR title LIKE '%" . $keyword ."%')
UNION
(SELECT content, title, 'comment' as type FROM comments WHERE content LIKE '%" . $keyword . "%' OR title LIKE '%" . $keyword ."%')";

Identifying Table Origin:

Once you have executed the combined query, you can identify the table of origin for each result row by looking at the 'type' column. Each row will have its 'type' value set to 'msg' (messages), 'topic' (topics), or 'comment' (comments), allowing you to easily categorize the results.

Conclusion:

By leveraging the UNION operator and utilizing a 'type' column to identify table origin, you can effectively perform multi-table keyword searches in PHP and MySQL. This technique provides a versatile and efficient way to search across multiple tables, enhancing data retrieval capabilities and streamlining your development process.

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