How to Find the Most Frequent Value in a SQL Column?

Finding the Most Frequent Value in SQL Column

In SQL, finding the most frequent value within a given column is a common data retrieval scenario. Let's explore how to achieve this efficiently.

Method:

The most widely used approach involves combining aggregation and ordering functions. Here's a step-by-step approach:

1. Select the Column and Count:

   SELECT <column_name>, COUNT(<column_name>) AS `value_occurrence`

   This statement selects the column you're interested in along with the number of times each unique value appears in the column.

2. GroupBy Column:

   GROUP BY <column_name>

   This clause groups the data by the column you've selected, ensuring that all occurrences of each unique value are counted separately.

3. OrderBy Count (Descending):

   ORDER BY `value_occurrence` DESC

   This statement sorts the results in descending order of count, placing the most frequent values at the top.

4. Limit to Top Row:

   LIMIT 1

   Finally, add the LIMIT clause to retrieve only the top-ranked row, representing the most frequent value.

Complete Query:

Combining these steps, the complete query will look like this:

SELECT
  <column_name>,
  COUNT(<column_name>) AS `value_occurrence` 

FROM
  <my_table>

GROUP BY 
  <column_name>

ORDER BY 
  `value_occurrence` DESC

LIMIT 1;

Example:

Consider the table mentioned in the question:

one
two
two
three

Using the query:

SELECT
  value,
  COUNT(value) AS `value_occurrence` 

FROM
  sample_table

GROUP BY 
  value

ORDER BY 
  `value_occurrence` DESC

LIMIT 1;

The result will be:

two

Customization:

To retrieve the N most frequent values, simply change the LIMIT 1 clause to LIMIT N.

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