Combining MySQL Tables: Updating Occurrence Counts for Matching IPs and Adding New Entries

Other Questions MySQL
1

I’m trying to merge two MySQL tables, ‘log1’ and ‘log2’, which have the same structure. Each table has columns for ‘id’, ‘IP’, and ‘occurrence_count’. Here’s what I want to do:

  1. For IPs that exist in both tables, add the ‘occurrence_count’ from ‘log2’ to ‘log1’.
  2. For IPs in ‘log2’ that don’t exist in ‘log1’, add a new row to ‘log1’ (without including the ‘id’ because it’s auto-incremented).

For example, if ‘log1’ has an IP ‘192.168.1.1’ with a count of 50 and ‘log2’ has the same IP with a count of 30, the result in ‘log1’ should update that count to 80.

I’m not sure how to accomplish this in a single SQL statement. Any suggestions on how to proceed? I’m using phpMyAdmin, if that helps. Thanks!

2

hey there! you could try something like this:

UPDATE log1 l1
LEFT JOIN log2 l2 ON l1.IP = l2.IP
SET l1.occurrence_count = l1.occurrence_count + IFNULL(l2.occurrence_count, 0);

INSERT INTO log1 (IP, occurrence_count)
SELECT IP, occurrence_count FROM log2
WHERE IP NOT IN (SELECT IP FROM log1);

this should do the trick for ya. let me kno if u need more help!

3

I’ve dealt with a similar situation before, and here’s what worked for me:

First, update the existing entries in log1:

UPDATE log1 l1
INNER JOIN log2 l2 ON l1.IP = l2.IP
SET l1.occurrence_count = l1.occurrence_count + l2.occurrence_count;

Then, insert the new entries from log2:

INSERT INTO log1 (IP, occurrence_count)
SELECT l2.IP, l2.occurrence_count
FROM log2 l2
LEFT JOIN log1 l1 ON l2.IP = l1.IP
WHERE l1.IP IS NULL;

This approach worked efficiently for me with large datasets. It first updates matching IPs and then inserts new ones. Just make sure to back up your data before running these queries. Hope this helps!