Question

i want to sort my table in this manner.
This is the current state of my table:

And this would be the outcome:

So basically in pseudo code it’s:

IF SAME STRING IN "tag" COLUMN THEN add both "power" 

Can anyone suggest an efficient way to achieve this if any?

Answer 1

Create a new table called t1_temp with the exact same structure as your original table called t1. The following should get the job done:

TRUNCATE t1_temp; INSERT INTO t1_temp (id, power, tag) VALUES (SELECT id, SUM(power), tag FROM t1 GROUP BY tag); RENAME TABLE t1 TO t1_temp2, t1_temp TO t1, t1_temp2 TO t1_temp

---

However, I will recommend that you try to modify your insert statement. Create a unique index on tag and then use something like the following (assuming that id is auto-increment)

INSERT INTO t1 (power, tag) VALUES (3, 'option1') ON DUPLICATE KEY UPDATE power = power + 3