How To Use LOAD DATA LOCAL INFILE REPLACE

Question

I have a script that I am using to migrate data from one db to another. I have already done so with using regular mysql insert and update scripts. It just takes way too long.

In any case I have dumped all of the data that I want to update in the new db to a csv, I am just worried that if I run this script I am going to get duplicate entries. I dont have an "id" that matches up so I can't do a comparison on the REPLACE script listed below. I was wondering if anyone could give me a heads up on whether or not this script looks correct.

Currently I have rows of data in the new db, I just want to overwrite any fields in the new db with this new data in the csv's if they match. The "archived_id_number" field is the only field that I could match on, but it is not a Primary Key.

Can someone shoot me the following:

I want to replace any data in fields with data in the csv's if the archived_id_number on the csv matches what is in the new db. If there is no match, the I want to insert the data as a new row.

$sql = '
LOAD DATA LOCAL INFILE "'.$theFile.'" 
REPLACE INTO TABLE Product 
FIELDS TERMINATED BY "|" 
LINES TERMINATED BY "\\n"
(archived_id_number, sku, name, upc, account_id, shippingBox_id, unit_cost, supplier_id, description, productLength, productWidth, productHeight)
;';

Thanks for your help!!!

Answer 1

As an elaboration of my comment, while your query looks fine I advise testing this against a copy of your current table. This will allow you to confirm precisely what will happen without risking your existing data. You can achieve this by doing the following 3 queries (obviously chuck in a the php to execute $sql).

$sql = '
    CREATE TABLE `_test_Product` LIKE Product; 
';

$sql = '
    INSERT `_test_Product` SELECT * FROM Product;
';

$sql = '
    LOAD DATA LOCAL INFILE "'.$theFile.'" 
    REPLACE INTO TABLE `_test_Product`
    FIELDS TERMINATED BY "|" 
    LINES TERMINATED BY "\\n"
    (
        archived_id_number, 
        sku, name, upc, account_id, shippingBox_id, unit_cost, 
        supplier_id, description, productLength, productWidth, productHeight
    );
';

(more info available in Duplicating a MySQL table, indexes and data )