php - MySQL order by date until a specific date, after it reverse order

Php - MySQL order by date until a specific date, after it reverse order

To achieve a custom ordering in MySQL where you order by date up to a specific date in ascending order and then reverse the order after that date, you can use a combination of conditional ordering in your ORDER BY clause.

Example Scenario

Suppose you have a table named events with a column event_date, and you want to order the events up to 2023-12-31 in ascending order, and events after 2023-12-31 in descending order.

Solution

You can use a conditional statement in the ORDER BY clause to achieve this. Here's how you can do it:

SELECT * FROM events ORDER BY CASE WHEN event_date <= '2023-12-31' THEN 0 ELSE 1 END, CASE WHEN event_date <= '2023-12-31' THEN event_date ELSE event_date END DESC;

Explanation

  1. Conditional Ordering:

    • The first CASE statement creates a flag where all dates up to 2023-12-31 are assigned 0 and dates after 2023-12-31 are assigned 1.
    • This ensures that dates up to 2023-12-31 are considered first in the ordering.

  2. Secondary Ordering:

    • The second CASE statement orders dates up to 2023-12-31 in ascending order.
    • For dates after 2023-12-31, the same event_date is used but in descending order by appending DESC to it.

Full Example

Let's assume your events table structure is as follows:

CREATE TABLE events ( id INT AUTO_INCREMENT PRIMARY KEY, event_name VARCHAR(255), event_date DATE );

Here's a full query with some sample data:

-- Sample Data INSERT INTO events (event_name, event_date) VALUES ('Event 1', '2023-11-01'), ('Event 2', '2023-12-01'), ('Event 3', '2024-01-15'), ('Event 4', '2024-02-20'), ('Event 5', '2023-10-30'); -- Custom Ordered Query SELECT * FROM events ORDER BY CASE WHEN event_date <= '2023-12-31' THEN 0 ELSE 1 END, CASE WHEN event_date <= '2023-12-31' THEN event_date ELSE event_date END DESC;

Result

The above query would produce the following ordered result:

id | event_name | event_date --------------------------------- 5 | Event 5 | 2023-10-30 1 | Event 1 | 2023-11-01 2 | Event 2 | 2023-12-01 4 | Event 4 | 2024-02-20 3 | Event 3 | 2024-01-15

Events up to 2023-12-31 are ordered in ascending order, and events after 2023-12-31 are ordered in descending order.

Examples

  1. PHP MySQL order by date then reverse order after specific date

    Description: Order by date ascending until a specific date and then descending.

    Code:

    $specific_date = '2023-01-01'; $query = " SELECT * FROM your_table ORDER BY CASE WHEN date_column < '$specific_date' THEN date_column ELSE NULL END ASC, CASE WHEN date_column >= '$specific_date' THEN date_column ELSE NULL END DESC ";

  2. MySQL custom order by date before and after a specific date

    Description: Custom order the results by date before and after a given date using a combined query.

    Code:

    $specific_date = '2023-01-01'; $query = " (SELECT * FROM your_table WHERE date_column < '$specific_date' ORDER BY date_column ASC) UNION ALL (SELECT * FROM your_table WHERE date_column >= '$specific_date' ORDER BY date_column DESC) ";

  3. How to order MySQL query by date until a specific date and then reverse

    Description: Combine two queries with UNION to order the dates differently before and after a specified date.

    Code:

    $specific_date = '2023-01-01'; $query = " (SELECT * FROM your_table WHERE date_column < '$specific_date' ORDER BY date_column ASC) UNION ALL (SELECT * FROM your_table WHERE date_column >= '$specific_date' ORDER BY date_column DESC) ";

  4. MySQL sort by date conditionally reversing after a given date

    Description: Use CASE statements to conditionally order dates ascending and descending.

    Code:

    $specific_date = '2023-01-01'; $query = " SELECT * FROM your_table ORDER BY CASE WHEN date_column < '$specific_date' THEN date_column END ASC, CASE WHEN date_column >= '$specific_date' THEN date_column END DESC ";

  5. PHP MySQL conditional ordering by date

    Description: Split the results into two different orderings using CASE statements.

    Code:

    $specific_date = '2023-01-01'; $query = " SELECT * FROM your_table ORDER BY CASE WHEN date_column < '$specific_date' THEN date_column ELSE NULL END ASC, CASE WHEN date_column >= '$specific_date' THEN date_column ELSE NULL END DESC ";

  6. Order MySQL results by date with split ordering after a specific date

    Description: Use a UNION to combine results ordered before and after a specific date.

    Code:

    $specific_date = '2023-01-01'; $query = " (SELECT * FROM your_table WHERE date_column < '$specific_date' ORDER BY date_column ASC) UNION ALL (SELECT * FROM your_table WHERE date_column >= '$specific_date' ORDER BY date_column DESC) ";

  7. MySQL order dates ascending until specific date then descending

    Description: Use CASE to order dates conditionally before and after a specific date.

    Code:

    $specific_date = '2023-01-01'; $query = " SELECT * FROM your_table ORDER BY CASE WHEN date_column < '$specific_date' THEN date_column ELSE NULL END ASC, CASE WHEN date_column >= '$specific_date' THEN date_column ELSE NULL END DESC ";

  8. PHP MySQL order by date with conditional reversal

    Description: Achieve conditional date ordering using CASE statements.

    Code:

    $specific_date = '2023-01-01'; $query = " SELECT * FROM your_table ORDER BY CASE WHEN date_column < '$specific_date' THEN date_column ELSE NULL END ASC, CASE WHEN date_column >= '$specific_date' THEN date_column ELSE NULL END DESC ";

  9. MySQL query order by date with custom split point

    Description: Split the date ordering using a specific date as a point of reversal.

    Code:

    $specific_date = '2023-01-01'; $query = " (SELECT * FROM your_table WHERE date_column < '$specific_date' ORDER BY date_column ASC) UNION ALL (SELECT * FROM your_table WHERE date_column >= '$specific_date' ORDER BY date_column DESC) ";

  10. How to sort MySQL dates ascending until specific date and then descending

    Description: Use UNION to merge two differently ordered sets of results.

    Code:

    $specific_date = '2023-01-01'; $query = " (SELECT * FROM your_table WHERE date_column < '$specific_date' ORDER BY date_column ASC) UNION ALL (SELECT * FROM your_table WHERE date_column >= '$specific_date' ORDER BY date_column DESC) ";

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