How to solve "array overflow", either in php or using MySQL?

Prior to the question How to use php to get a unique word (string) pair and insert into a mysql table, you should first read

eg: if we have a pair dog cat

, we will not seecat dog

As @pala_ suggestion here is my code

 $sql= "INSERT INTO EM (source,target) VALUES ";

$res = array();
foreach($combine_words_array as $v1) {
  foreach($combine_words_array as $v2) {
    $t = array($v1, $v2);
    if(!in_array($t, $res)){
      $res[] = $t;


and the question comes up, this array must be very huge, and MySQL insert stop in 540000

rows, any idea that can use dynamic array or together with MySQL code?


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1 answer

I still think you should keep this logic in SQL as such:

SELECT t1.column AS source, t2.column AS target FROM input_table t1
INNER JOIN input_table t2 ON t1.column < t2.column


This should give you all the unique pairs and should be faster than getting a unique pair with PHP in_array testing. if the data is already in PHP and not MySQL, you can insert rows 540000

at that time into a temporary table and then run something like above to get the pairs you are interested in. Databases are designed to work with a lot, PHP definitely isn't.

If you insist on creating an array the way you do, and keep the whole thing in PHP memory, you should only run the string mysql_query(substr($sql,0,-1));

if you've reached the limit of your string or ended an outer loop. At this point you can reset the $ sql string to

$sql= "INSERT INTO EM (source,target) VALUES ";

again and start building the remainder of the building as you have so far. Flush and repeat until you are done or PHP process is not working =)



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