How to Efficiently Retrieve Records Based on Multiple Values in a Single Database Column?

Retrieving Records Based on Multiple Column Values

In scenarios where a single database column contains multiple values, executing queries to retrieve records based on those values can be challenging. This is exemplified by the need to find parents who have a child named Alex.

The traditional approach of using "WHERE children = 'Alex'" is not feasible due to the presence of multiple names within the children column. Alternatives such as "WHERE children LIKE '%Alex%'" return broader results, including names that start with Alex (e.g., Alexandre). To precisely match single values, normalization of the schema is recommended.

Normalization involves creating a separate table with a separate row for each child. By joining this table with the parent table, it becomes possible to identify parents with specific children.

For scenarios where normalization is not an option, another technique is to utilize the FIND_IN_SET function:

WHERE FIND_IN_SET('Alex', children)

This function searches for a specific substring ('Alex' in this case) within the children column and returns a numeric index if found. Matching records will have an index greater than 0, facilitating effective filtering.

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