PHP 代码插入/更新/删除 SQL 数据库中的条目

Question

I have two databases, one very big (5 GB) and a smaller one which is updated with a PHP running as a cron job to extract the necessary data from the big database.

I have so far been able to extract the data from the big database and insert it in the small one if the row doesn't already exist.

This is how a database row looks like:

123456 TeamA-TeamB 1.14 4.30 7.60
(id, eventname, odds1, oddsX, odds2)

The PHP needs to a) check whether the row exists, b1) add it if it doesn't exist, b2) if it does exist check do the values odds1, oddsX and odds2 differ, c) if they do, update the values.

This is the code which does a) and b1):

$SQL_INSERT="INSERT IGNORE INTO oddsnavi_baby.calc (id, eventname, odds1, oddsX, odds2) VALUES ('$eventid', '$eventname', '$odds1', '$oddsX', '$odds2')";
mysql_db_query($database_baby, $SQL_INSERT) or die("Failed Query of " . $SQL_INSERT);

How do I change this part to get the row updated if the existing values of either odds1, oddsX or odds2 are different than the ones intended to be written to the database? It would also be fine if the row would be updated if any value is different, as the first two won't change anyway.

Answer 1

$SQL_INSERT="INSERT IGNORE INTO oddsnavi_baby.calc (id, eventname, odds1, oddsX, odds2) VALUES ('$eventid', '$eventname', '$odds1', '$oddsX', '$odds2')";
$SQL_UPDATE="update oddsnavi_baby.calc set odds1=\"$odds1\",oddsX=\"$oddsX\",odds2=\"$odds2\" where id=\"$eventid\");
$query="select * from oddsnavi_baby.calc where id=\"$eventid\"";
$process=mysql_query($query);
if(mysql_num_rows($process))       
        mysql_db_query($SQL_UPDATE);
else
        mysql_db_query($database_baby, $SQL_INSERT) or die("Failed Query of " . $SQL_INSERT);

here in this case there is a redundancy if there is no change in row data then also it will be updates which would be an overhead. Checking for values could reduce it

Answer 2

Try:

REPLACE INTO 

instead of INSERT IGNORE INTO.

Docs here: http://dev.mysql.com/doc/refman/5.0/en/replace.html