MySql选择计数直到找到一定的值

Question

id  number my_id
 1    1     789  
 1    2     645
 1    3     222
 1    4     544
 1    5     155

With simple count result will equal 5

SELECT COUNT(id) AS count FROM table WHERE id = 1 

How I can count until find a certain value?

For example: count until my_id is '222' with count result = 3

Thank you!

Answer 1

That depends on the order, what do you mean by "until my_id is 222"?

You can make a query like this(or the opposite) but this will use the my_id field to determine who should be counted:

SELECT count(id) as count
FROM YourTable
WHERE id = 1 AND my_id <= 222

EDIT: Your question missing some crucial information, but maybe you meant this:

SELECT COUNT(t.id) as count
FROM YourTable t
WHERE t.id = 1
  AND t.number <= (SELECT number FROM YourTable s
                   WHERE s.id = 1 and S.my_id = 222)

This query is relying on the fact the only 1 record will match the inner query .

SQLFiddle

Answer 2

假设数字已排序

select count(*) from t where `number`<=(select `number` from t where my_id=222)