I also included this SQL - which lets you easily count (manually) the number of UNIQUE entries. ROW_NUMBER() OVER (PARTITION BY status_to ORDER BY status_to) AS rn Let us first create a table mysql> create table DemoTable ( Id int NOT NULL AUTOINCREMENT PRIMARY KEY, Amount int ) Query OK, 0 rows affected (0. This query demonstrates how you can easily pick out those DISINCT values of status_to that have more than one record: SELECT COUNT(rn) OVER (PARTITION BY rn) AS "Unique count" Get the sum of a column in all MySQL rows - Use aggregate function SUM() to get the sum of a column in al rows. Syntax SUM ( expression) Parameter Values Technical Details Works in: From MySQL 4. Notice the extreme difference in the results of EXPLAIN ANALYZE at the bottom of the fiddle for this new query and my old one! SELECT SUM (Quantity) AS TotalItemsOrdered FROM OrderDetails Try it Yourself Definition and Usage The SUM () function calculates the sum of a set of values. it's much more difficult with "classic" SQL - with window functions, it's quite easy.ĬOUNT(DISTINCT(status_to)) AS "Unique count" Note that I have added 2 singleton values ( Single_1 and Single_2) to examine how one would, for example, count the DISTINCT values which had greater than 1 record in your table. Then populate it: INSERT INTO test VALUES You can do something like the following (all the code below is available on the fiddle here): CREATE TABLE test There's a far easier way to do what you want - I was thinking about this last night - see my second fiddle here.
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