How to count two separate columns from two different tables? [duplicate] - sql

Question

This question already has answers here:
Combining the results of two SQL queries as separate columns
(4 answers)
Closed 3 years ago.
I am trying to query two different columns from two different table where I could count the number of certain column. I could do it in two separate query but I think it would create a slowdown in the future. What I want is a single query where I could display both of those counts in a single query only.
I tried using two separated select statements but I think is not good, I also tried using Union All, but the results are not what I expected.
upload_monitoring (12 Columns)
upm_FileName | upm_Status
----------------+--------------
Monitoring_0608 | Distributed
Monitoring_0607 | Distributed
Monitoring_0606 | Distributed
Monitoring_0605 | Uploaded
(100 rows)
distribute_monitoring (7 Columns)
dist_ProductName | dist_Status
-------------------+--------------
Monitoring_0608 | Pending
Monitoring_0607 | Pending
Monitoring_0606 | Pending
Monitoring_0605 | Touched
(100 rows)
I tried with these:
$query2 = "
SELECT
COUNT(upm_Status) AS total_DistItems
FROM
upload_monitoring
WHERE
upm_Status = 'Distributed'
AND
upm_FileName = '$upm_FileName'
";
$result2 = mysqli_query($connection, $query2);
$fetchResult2 = mysqli_fetch_assoc($result2);
$total_DistItems = $fetchResult2['total_DistItems'];
$query3 = "
SELECT
COUNT(dist_Status) AS total_PendItems
FROM
distribute_monitoring
WHERE
dist_Status = 'Pending'
AND
dist_Product = '$upm_FileName'
";
$result3 = mysqli_query($connection, $query3);
$fetchResult3 = mysqli_fetch_assoc($result3);
$total_PendItems = $fetchResult3['total_PendItems'];
I also tried with these one
$query2 = "
SELECT
upm_Status,
COUNT(upm_Status) AS total_DistItems
FROM
upload_monitoring
WHERE
upm_Status = 'Distributed'
AND
upm_FileName = '$upm_FileName'
UNION ALL
SELECT
dist_Status,
COUNT(dist_Status) AS total_PendItems
FROM
distribute_monitoring
WHERE
dist_Status = 'Pending'
AND
dist_Product = '$upm_FileName'
";
$result2 = mysqli_query($connection, $query2);
however the result is
upm_Status | total_DistItems
------------+--------------
Distributed | 34
Pending | 12
What I expect the result to be is like this one.
upm_Status | total_DistItems | dist_Status | total_PendItems
------------+-----------------+-------------+-----------------
Distributed | 34 | Pending | 12

Answer 1

Here is one method:
SELECT u.*, d.*
FROM (SELECT 'Distributed' as upm_Status,
COUNT(*) AS total_DistItems
FROM upload_monitoring
WHERE upm_Status = 'Distributed' AND
upm_FileName = ?
) u CROSS JOIN
(SELECT 'Pending' as dist_Status, COUNT(dist_Status) AS total_PendItems
FROM distribute_monitoring
WHERE dist_Status = 'Pending' AND
dist_Product = ?
) d;
Note that I replaced the $upm_filename with ?. This indicates that you should be using parameters to pass values into the query, rather than munging the query string with such values. Your method puts you at risk for unexpected syntax errors and SQL injection attacks.