How Can I Combine Multiple MySQL Rows into a Single Field Using GROUP_CONCAT?

Consolidating Multiple MySQL Rows into a Single Field with GROUP_CONCAT

Need to combine data from multiple rows into a single field in your MySQL results? When joining tables, you might end up with more rows than you need. MySQL's GROUP_CONCAT function provides an elegant solution.

This function concatenates values from multiple rows into a single string within a group. Here's how it works:

<code class="language-sql">SELECT person_id,
       GROUP_CONCAT(hobbies SEPARATOR ', ') AS hobbies_list
FROM peoples_hobbies
GROUP BY person_id;</code>

This query efficiently compiles all hobbies for each person into a single comma-separated string within the hobbies_list column.

For even greater control, consider these options:

• DISTINCT: Avoid duplicate entries in the concatenated string.
• ORDER BY: Arrange the values before concatenation for a specific order.
• SET group_concat_max_len = <value>: Adjust the maximum length of the resulting string (the default is 1024 bytes). You'll need to adjust this if your concatenated string exceeds this limit.

By using these features, you can effectively manage and present your MySQL data in a more compact and organized format, perfectly tailored to your needs.

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