From the Oracle docs ROWID Pseudocolumn For each row in the database, the ROWID pseudocolumn returns the address of the row. Oracle Database rowid values contain information necessary to locate a row: The data object number of the object The data block in the datafile in which the row resides The position of the row … Read more
Take a look at this. Change your query to: SET @rank=0; SELECT @rank:=@rank+1 AS rank, itemID, COUNT(*) as ordercount FROM orders GROUP BY itemID ORDER BY ordercount DESC; SELECT @rank; The last select is your count.
For the first question, why not just use? SELECT COUNT(*) FROM myTable to get the count. And for the second question, the primary key of the row is what should be used to identify a particular row. Don’t try and use the row number for that. If you returned Row_Number() in your main query, SELECT … Read more
There is no ranking functionality in MySQL. The closest you can get is to use a variable: SELECT t.*, @rownum := @rownum + 1 AS rank FROM YOUR_TABLE t, (SELECT @rownum := 0) r so how would that work in my case? I’d need two variables, one for each of col1 and col2? Col2 would … Read more