如何将两个查询与不同的WHERE / LIKE条件结合使用？

Question

My two queries:

$compareTotals1 = mysqli_query($con,"
    SELECT *,   (SUM(rent_amount)+SUM(late_fees)-SUM(discount_amount)) AS total,
                SUM(late_fees) AS latefees,
                SUM(discount_amount) AS discounts
    FROM        transaction
    WHERE       paid_on LIKE '%2014%'
");
$compareTotals2 = mysqli_query($con,"
    SELECT *,   (SUM(rent_amount)+SUM(late_fees)-SUM(discount_amount)) AS total,
                SUM(late_fees) AS latefees,
                SUM(discount_amount) AS discounts
    FROM        transaction
    WHERE       paid_on LIKE '%2015%'
");

How I'm outputting results:

if ($row = mysqli_fetch_array($compareTotals1)) {
    echo CURRENCY.number_format($row['total'],2);
    echo CURRENCY.number_format($row['latefees'],2);
    echo CURRENCY.number_format($row['discounts'],2);
} else { 
    echo "No Records."; 
}

if ($row = mysqli_fetch_array($compareTotals2)) {
    echo CURRENCY.number_format($row['total'],2);
    echo CURRENCY.number_format($row['latefees'],2);
    echo CURRENCY.number_format($row['discounts'],2);
} else { 
    echo "No Records."; 
}

The paid_on LIKE '% %' is generated dynamically by a dropdown box and some javascript. That's the only part that changes.

How can I condense this into one query so I only need to use one mysqli_fetch_array ?

Answer 1

Assuming you want multiple rows a union is likely the cleanest

$compareTotals1 = mysqli_query($con,"
    SELECT *,   (SUM(rent_amount)+SUM(late_fees)-SUM(discount_amount)) AS total,
                SUM(late_fees) AS latefees,
                SUM(discount_amount) AS discounts,
                '2014' as Yr
    FROM        transaction
    WHERE       paid_on LIKE '%2014%'
    UNION ALL
    SELECT *,   (SUM(rent_amount)+SUM(late_fees)-SUM(discount_amount)) AS total,
                SUM(late_fees) AS latefees,
                SUM(discount_amount) AS discounts,
                '2015' as Yr
    FROM        transaction
    WHERE       paid_on LIKE '%2015%'
");

You may be able to combine the where's into an OR and be sure to spell out a group by or you will not know which is 2015 or 2014 unless * includes such details.

$compareTotals1 = mysqli_query($con,"
    SELECT *,   (SUM(rent_amount)+SUM(late_fees)-SUM(discount_amount)) AS total,
                SUM(late_fees) AS latefees,
                SUM(discount_amount) AS discounts,
                case when paid_on like '%2014%' then '2014' 
                     when paid_on like '%2015%' then '2015' end as yr
    FROM        transaction
    WHERE       paid_on LIKE '%2014%'
       OR       paid_on LIKE '%2015%'
   --GROUP BY    all fields from select relevant to group by... without structure and sample data from table can't figure out.
   -- This might work though I'd be concerned all the * columns could be returning improper results.
   GROUP BY case when paid_on  like '%2014%' then '2014' when paid_on like '%2015%' then '2015' end
");

maybe... group by case when paid_on like '%2014%' then '2014' when paid_on like '%2015%' then '2015' end but this is very specific.

we might be able to group by paid_on, but it appears it's not just a year... so you may get multiple rows per year... so again without sample data for structure can't figure out what to do.

Or maybe you want a cross join more columns... not more rows...

$compareTotals1 = mysqli_query($con,"
    Select * from (
    SELECT *,   (SUM(rent_amount)+SUM(late_fees)-SUM(discount_amount)) AS total,
                SUM(late_fees) AS latefees,
                SUM(discount_amount) AS discounts
    FROM        transaction
    WHERE       paid_on LIKE '%2014%') CROSS JOIN

    (SELECT *,   (SUM(rent_amount)+SUM(late_fees)-SUM(discount_amount)) AS total,
                SUM(late_fees) AS latefees,
                SUM(discount_amount) AS discounts
    FROM        transaction
    WHERE       paid_on LIKE '%2015%') B
");

Answer 2

Why not just use an OR in your WHERE?

$compareTotals1 = mysqli_query($con,"
    SELECT *,   (SUM(rent_amount)+SUM(late_fees)-SUM(discount_amount)) AS total,
                SUM(late_fees) AS latefees,
                SUM(discount_amount) AS discounts
    FROM        transaction
    WHERE       paid_on LIKE '%2014%'
        OR      paid_on LIKE '%2015%'
    GROUP BY    YEAR(paid_on) -- is `paid_on` a date?
");