sql中带有单独组的最新结果

Question

I have table data like below image.

Per we enter 6 records in 3times. (morning 2, afternoon 2, evening 2)

When I search by DATE, I want to get the result like below image.

I want to foreach that result like below.

I tried this sql query but no luck.

select c.currency, c.date, c.textbody
                from currencies c
                inner join (
                    select currency, max(date) as MaxDate
                    from currencies
                    group by currency
                ) cc on c.currency = cc.currency and c.date = cc.MaxDate
                where date ='2017-11-20'
                group by currency
                order by currency'

Story of the Requirement Per day user enter 6 records in 3 session of the time, When the morning time user enter 2 records(EURUSD and GBPUSD). I will display then in a web page as one group. Then in the evening user enter another 2 records(EURUSD and GBPUSD), after that I need to show the latest 2 records are in the top group and previous 2 records and below. per day 6 records 3 groups.

Answer 1

I think you search for GROUP BY timestamp like this:

SELECT GROUP_CONCAT(currency) AS currencies, GROUP_CONCAT(text_body) AS text_bodyies, GROUP_CONCAT(timestamp) AS inserted_time
FROM currencies
WHERE date = '2017-11-20'
GROUP BY 
CASE 
    WHEN HOUR(timestamp) < 14 THEN 1 -- MORNING
    WHEN HOUR(timestamp) < 17 THEN 2 -- AFTERNOON
    WHEN HOUR(timestamp) < 21 THEN 3 -- EVENING
END
ORDER BY timestamp DESC

Answer 2

Make simple query:

 SELECT currency, textBody FROM currencies 
 WHERE date = '2017-11-20'
 ORDER BY timestamp, currency

Then fetch the data to the $rows array, add a check to display only the paired rows and display them. In PHP this will be as follows:

$rowsCount = count($rows);

if (in_array($rowsCount, [2, 4, 6])) {

    for ($i = 0; $i < $rowsCount; $rowIndex++) {
        echo $rows[$i]['currency'] . ' ' . $rows[$i + 1]['currency'] . ' ' 
            . $rows[$i]['textbody'] . ' ' . $rows[$i + 1]['textbody'].PHP_EOL;
        $rowIndex += 1;
    }
}