当每行的值发生变化时，计算有多少行具有指定值

Question

When I was querying a table by a specific id I would also count how many rows in that table shared the same name:

SELECT *, COUNT(name) FROM table WHERE id = 24601

Now I'm no longer querying a table by a specific id, instead getting all of the table's output. Is there a way I could still get that count for each row?

SELECT *, COUNT(this specific row's name) FROM table

Answer 1

If you want to get the count of rows per name , then use GROUP BY :

SELECT name, COUNT(*) AS count 
FROM table
GROUP BY name

You'll get one row per distinct value of name , with a second column that has the integer count.

If you also need the other columns for each row, you should write that as a separate query. Don't combine aggregated results with non-aggregated results in the same query.