I have the following prepared statement to run a dynamic pivot query across three tables
SET @sql = NULL;
SELECT GROUP_CONCAT(DISTINCT CONCAT(
'max(case when division_id = ', dp.division_id, ' then process_name end) AS ', d.division_shortName, ' '
)
) INTO @sql
FROM
erp_divisionProcess dp LEFT JOIN erp_division d ON d.division_id = dp.division_id;
SET @sql = concat('SELECT ', @sql, 'FROM (
SELECT d.division_id, p.process_name, X.rnk
FROM erp_division d
LEFT JOIN (SELECT dp.division_id, dp.process_id, (SELECT COUNT(*) FROM erp_divisionProcess A WHERE dp.division_id = A.division_id AND dp.process_id < A.process_id) AS rnk
FROM erp_divisionProcess dp) X ON X.division_id = d.division_id
LEFT JOIN erp_BusinessProcess p ON p.process_id = X.process_id
) x
GROUP BY rnk');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
which produces a pivoted dataset like this:
+-----------------+-----------------+------------+------------+--------------+------------+------------+-------+
| PBL | PLI | PMI | PBT | PBP | PBI | PBTL | PRDT |
+-----------------+-----------------+------------+------------+--------------+------------+------------+-------+
| Sales | Human Resources | Production | Purchasing | Sales | Purchasing | Purchasing | Sales |
| Human Resources | Purchasing | NULL | NULL | Purchasing | NULL | NULL | NULL |
| Purchasing | Finance | NULL | NULL | Distribution | NULL | NULL | NULL |
| Distribution | NULL | NULL | NULL | Production | NULL | NULL | NULL |
| Production | NULL | NULL | NULL | NULL | NULL | NULL | NULL |
| Finance | NULL | NULL | NULL | NULL | NULL | NULL | NULL |
+-----------------+-----------------+------------+------------+--------------+------------+------------+-------+
I'd like the resulting dataset to be available to pull into Excel, but MS Query throws and error when I try and run the full statement. I believe I can't create a view from the prepared statement, so how can I have the query result available without having to retype (copy and paste) it every time and get the results out of MySQL.
Thanks!
I believe I can't create a view from the prepared statement, so how can I have the query result available without having to retype (copy and paste)
You can create a view
using Prepared Queries.
Try following change in your code:
-- SET @sql = concat('SELECT ', @sql, 'FROM (
SET @sql = concat( 'CREATE VIEW view_name AS SELECT ', @sql, ' FROM (
SELECT d.division_id, p.process_name, X.rnk
FROM erp_division d
LEFT JOIN (SELECT dp.division_id, dp.process_id,
(SELECT COUNT(*) FROM erp_divisionProcess A
WHERE dp.division_id = A.division_id
AND dp.process_id < A.process_id) AS rnk
FROM erp_divisionProcess dp) X
ON X.division_id = d.division_id
LEFT JOIN erp_BusinessProcess p ON p.process_id = X.process_id
) Y
GROUP BY rnk');
Once view is created, you can issue a select * from view_name
to fetch data into client.
Demo @ MySQL 5.5.32 Fiddle
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.