Six-seven years ago when I started with Magento, the import feature was lacking. While it improved, it still has quite a few issues even today. Mostly every import task I worked on was delayed due to unexpected core bugs. Extensions that promise to help with this come with their own set of issues. There is hope with the https://github.com/magento-engcom/import-export-improvements project, but till that’s done we have to get by.
First, the imports do not have a programmatic interface you can hook into, i.e. pass an array with data and get it imported. Luckly, Firegento fixed this with https://github.com/firegento/FireGento_FastSimpleImport2 . The module is just a simple wrapper over the standard import, so not many chances to break. Of course there is the standard Magento 2 product API, but it’s pretty useless for anything else than a few products due to slowness.
The second thing I ran into is that tier price imports are a special entity, i.e. you first import the product data in a format, then import the tier pricing in a totally different one. This is not what a merchant would expect and sadly, not even the Firegento extension has a programmatic interface for tiers.
Then another gotcha is that importing empty values does nothing by default. So if you set a product color, then decide to unset it by importing an empty value, it will still keep the same value as before. Similarly, if you import category associations and want to remove an older association, you are out of luck, the old link remains. This is almost a “feature” in Magento – https://github.com/magento/magento2/issues/7930 . The proposed fix is to use the “Replace” behaviour of imports, but that creates another issue – with “Replace”, product data is wiped out and recreated. Not something you want todo if you care about stats/old orders since all the product IDs will change.
Another nuisance is that all custom attributes need to be crammed in a single csv field like:
For most of my clients, additional attributes is where the bulk of the data lives, so having them formatted as above is clunky.
For the good parts, the import is pretty fast, it can import images correctly and once you get the format right, most of the stuff works.
The conclusion? If you’re working on a import task, pad your estimates substantially, you will need the time to go through a various set of quirks you never thought of. By the way, all of the above refers strictly to the simple products, other product types might come with their own set of problems.