Question

I hope someone can help me out. I have a table that logs our import jobs. I need a query that will produce a matrix with the names of tables on the vertical axis, the import dates on the horizontal axis, and the total number of records imported for that table on that date in the matrix cell. I don’t care if we have to create a temporary table, but the whole thing must be done in MySQL.

Below is a simplified sample of our event log table. Not only does it have many more fieds, but we import many more tables. Therefore, the solution should account for querying the table names. You will notice that data can be imported into a table more than once per day, as in records 5 and 6.

id  table_name  import_date          num_recs 
----+-----------+--------------------+------- 
0   customer    2010-06-20 00:00:00  10        
1   order       2010-06-20 00:00:00  15        
2   customer    2010-06-21 00:00:00  5         
3   order       2010-06-21 00:00:00  6         
4   customer    2010-06-22 00:00:00  1         
5   order       2010-06-22 00:00:00  6         
6   order       2010-06-22 00:00:00  1         

We are looking for a result something like this. It does not have to be exact

table_name  06-20 06-21 06-22
------------+-----+-----+------
customer    |  10 |   5 |   1
order       |  15 |   6 |   7

Answer 1

What about output of the form:

table_name   date    imports
------------+-------+--------
customer    | 06-20 |   10
customer    | 06-21 |   5
order       | 06-20 |   15
order       | 06-21 |   6

This way you can do it with a simple GROUP BY:

SELECT table_name, DATE(import_date) AS date, SUM(*) AS imports
FROM yourTable
GROUP BY table_name, date;

Otherwise, your query is going go be really nasty.