how to approach this in MySql query? - mysql

Question

I want to select the data as per condition:I have a table with physician_key and corresponding quality score for a given month. I want to select count of distinct physicians with quality score 1,2.
For a month, there could be more entries for a physician_key and accordingly the quality assigned(on scale 1-7). I want to select only the count of those physicians which have quality (1,2) and if the same physician has quality >2 in given month, I don't want to count that physician.I want the information by product and month

Answer 1

I created an example table, since you didn't provide one:
mysql> select * from sales_mkt_rep_qual;
+-------------------+---------+-------+-------------------+
| GEO_PHYSICIAN_KEY | product | month | SALES_REP_QUALITY |
+-------------------+---------+-------+-------------------+
| 1 | a | 8 | 1 |
| 1 | a | 8 | 2 |
| 1 | a | 8 | 3 |
| 2 | b | 8 | 2 |
| 2 | b | 8 | 1 |
| 2 | b | 9 | 2 |
| 1 | a | 9 | 2 |
| 2 | b | 9 | 3 |
| 3 | a | 9 | 2 |
+-------------------+---------+-------+-------------------+
The query from your comment indeed gives an error:
SELECT COUNT(DISTINCT GEO_PHYSICIAN_KEY) AS encount_1to2,
product,MONTH
FROM sales_mkt_rep_qual
WHERE MAX(SALES_REP_QUALITY) = 2 ;
ERROR 1111 (HY000): Invalid use of group function
If you change that to:
SELECT DISTINCT geo_physician_key AS encount_1to2, product, month
FROM sales_mkt_rep_qual
WHERE (geo_physician_key,month,product)
NOT IN (
SELECT geo_physician_key, month, product
FROM sales_mkt_rep_qual
WHERE sales_rep_quality >2 );
you see the detailed result:
+--------------+---------+-------+
| encount_1to2 | product | month |
+--------------+---------+-------+
| 2 | b | 8 |
| 1 | a | 9 |
| 3 | a | 9 |
+--------------+---------+-------+
No, you can introduce the counting:
SELECT COUNT(distinct geo_physician_key ) AS no_of_physicians,product, month
FROM sales_mkt_rep_qual
WHERE (geo_physician_key,month,product)
NOT IN (
SELECT geo_physician_key, month, product
FROM sales_mkt_rep_qual WHERE sales_rep_quality >2 )
GROUP BY month, product;
+------------------+---------+-------+
| no_of_physicians | product | month |
+------------------+---------+-------+
| 1 | b | 8 |
| 2 | a | 9 |
+------------------+---------+-------+
If that still isn't what you are looking for, give more specific table structure and data example.

Answer 2

Try this:
SELECT count(DISTINCT physician_key)
FROM my_table
WHERE month = desired_month
AND max(quality) = 2
GROUP BY month

Answer 3

Actually I want the data to be like the output below:
+--------------+---------+-------+
| encount_1to2 | product | MONTH |
+--------------+---------+-------+
| 2 | b | 8 |
+--------------+---------+-------+
and for the criteria SALES_REP_QUALITY <= 2, isn't there a possibility that while selecting the distinct geo physician key, it might select out of first 2 considering it matches the criteria? Thats the reason I have used Thanix approach of max function with group by product and month, so that the aggregate function is applied on every product within a month