Import Large CSV file into MySQL
I am trying to import a csv file into a mysql table and I currently have a script that is running line by line because I need to hash an id combined with another id as well as format the date for mysql format.
The csv file has MORE columns than I am currently importing. Is it easier to just import all columns?
I was reading about LOAD DATA INFILE (http://dev.mysql.com/doc/refman/5.1/en/load-data.html), but I am wondering how I can use this and hash the ids and format the date without doing row by row execution. My current script is taking way too long and causing site performance issues while running.
Here is what I have:
$url = 'http://www.example.com/directory/file.csv';
if (($handle = fopen($url, "r")) !== FALSE)
{
fgetcsv($handle, 1000, ",");
while (($data = fgetcsv($handle, 1000, ",")) !== FALSE)
{
$EvID = $data[0];
$Ev = $data[1];
$PerID = $data[2];
$Per = $data[3];
$VName = $data[4];
$VID = $data[5];
$VSA = $data[6];
$DateTime = $data[7];
$PCatID = $data[8];
$PCat = $data[9];
$CCatID = $data[10];
$CCat = $data[11];
$GCatID = $data[12];
$GCat = $data[13];
$City = $data[14];
$State = $data[15];
$StateID = $data[16];
$Country = $data[17];
$CountryID = $data[18];
$Zip = $data[19];
$TYN = $data[20];
$IMAGEURL = $data[21];
$URLLink = $data[22];
$data[7] = strtotime($data[7]);
$data[7] = date("Y-m-d H:i:s",$data[7]);
if((($PCatID == '2') && (($CountryID == '217') or ($CountryID == '38'))) || (($GCatID == '16') or ($GCatID == '19') or ($GCatID == '30') or ($GCatID == '32')))
{
if(!mysql_query("INSERT IGNORE INTO TNDB_CSV2
(id, EvID, Event, PerID, Per, VName,
VID, VSA, DateTime, PCatID, PCat,
CCatID, CCat, GCatID, GCat, City,
State, StateID, Country, CountryID, Zip,
TYN, IMAGEURL) VALUES
('".md5($EventID.$PerformerID)."','".addslashes($data[0])."','".addslashes($data[1])."','".addslashes($data[2])."','".addslashes($data[3])."','".addslashes($data[4])."',
'".addslashes($data[5])."','".addslashes($data[6])."','".addslashes($data[7])."','".addslashes($data[8])."','".addslashes($data[9])."',
'".addslashes($data[10])."','".addslashes($data[11])."','".addslashes($data[12])."','".addslashes($data[13])."','".addslashes($data[14])."',
'".addslashes($data[15])."','".addslashes($data[16])."','".addslashes($data[17])."','".addslashes($data[18])."','".addslashes($data[19])."',
'".addslashes($data[20])."','".addslashes($data[21])."')"))
{
exit("<br>" . mysql_error());
}
}
}
fclose($handle);
}
Any help is always greatly appreciated. Thanks in advance.
Answer
try optimising your scripts first. First off, never run single queries when importing unless you have no other choice, the network overhead can be a killer.
Try something like (obviously untested and coded in the SO textbox, check brackets match e.c.t.):
$url = 'http://www.example.com/directory/file.csv';
if (($handle = fopen($url, "r")) !== FALSE)
{
fgetcsv($handle, 1000, ",");
$imports = array();
while (($data = fgetcsv($handle, 1000, ",")) !== FALSE)
{
$EvID = $data[0];
$Ev = $data[1];
$PerID = $data[2];
$Per = $data[3];
$VName = $data[4];
$VID = $data[5];
$VSA = $data[6];
$DateTime = $data[7];
$PCatID = $data[8];
$PCat = $data[9];
$CCatID = $data[10];
$CCat = $data[11];
$GCatID = $data[12];
$GCat = $data[13];
$City = $data[14];
$State = $data[15];
$StateID = $data[16];
$Country = $data[17];
$CountryID = $data[18];
$Zip = $data[19];
$TYN = $data[20];
$IMAGEURL = $data[21];
$URLLink = $data[22];
$data[7] = strtotime($data[7]);
$data[7] = date("Y-m-d H:i:s",$data[7]);
if((($PCatID == '2') && (($CountryID == '217') or ($CountryID == '38'))) || (($GCatID == '16') or ($GCatID == '19') or ($GCatID == '30') or ($GCatID == '32')))
{
$imports[] = "('".md5($EventID.$PerformerID)."','".addslashes($data[0])."','".addslashes($data[1])."','".addslashes($data[2])."','".addslashes($data[3])."','".addslashes($data[4])."',
'".addslashes($data[5])."','".addslashes($data[6])."','".addslashes($data[7])."','".addslashes($data[8])."','".addslashes($data[9])."',
'".addslashes($data[10])."','".addslashes($data[11])."','".addslashes($data[12])."','".addslashes($data[13])."','".addslashes($data[14])."',
'".addslashes($data[15])."','".addslashes($data[16])."','".addslashes($data[17])."','".addslashes($data[18])."','".addslashes($data[19])."',
'".addslashes($data[20])."','".addslashes($data[21])."')";
}
}
$importarrays = array_chunk($imports, 100);
foreach($importarrays as $arr) {
if(!mysql_query("INSERT IGNORE INTO TNDB_CSV2
(id, EvID, Event, PerID, Per, VName,
VID, VSA, DateTime, PCatID, PCat,
CCatID, CCat, GCatID, GCat, City,
State, StateID, Country, CountryID, Zip,
TYN, IMAGEURL) VALUES ".implode(',', $arr)){
die("error: ".mysql_error());
}
}
fclose($handle);
}
Play around with the number in array_chunk, too big and it may cause problems like the query being too long (yes there is a configurable limit in my.cnf), too small and its unneccassary overhead.
You could also drop the use of assign the $data[x] to variables as its a waste given how small the script is, just use the $data[x] directly in your query e.c.t. (wont give a massive improvement, but depending on your import size it could save a little).
Next thing would be to use low priority inserts/updates, check out this for more info on that to get you started: How to give priority to certain queries?
after all of that, you could think of mysql config optimisation's, but that's one for google to explain really as the best settings are different for everyone and their unique situations
Edit: Another thing i've done before is if you have a lot of keys set up that aren't required for the import, you can drop those keys temporarily and add them back when the script is done. This can yield good time improvements too, but as your working on a live database there are pitfalls to work around if you go down that route.