Make a BACKUP before doing anything to the database. Be safe.

Assumptions

This post assumes that

• the store_id for Default store is 0
• you have only 1 multi-store
• you are moving things from Multi-store to Default store
• you want to delete Multi-Store
• you have products that were added to both Default and Multi-store
• everything means products, categories, manufacturers and information

We can’t delete a multi-store if there are orders associated with it. So the first step of the process would be to update all existing orders to associate with our main (default) store.

Update Store details for all existing Orders

The table to edit is oc_order and the columns we’ll be editing are store_id, store_name and store_url. The store_id for the Default store is 0.

UPDATE `oc_order` SET `store_id`=0,`store_name`="Cakebox.ME", `store_url`="http://cakebox.me"

Using this command, you can change Store details for all existing orders. Once you have linked all existing orders to the default store, you can go to the Admin and delete the multi-store.

Cleanup

After we’re done with deleting multi-store, we need to do cleanup. For every Product, Category, Manufacturer, and Information page that was linked to the multi-store, there’ll be a row in the database saying so. If you had hundreds of products for your multi-store, there’ll be hundreds of rows for it in the database.

We need to a) update these rows to link to our Default store (in case you are moving everything to the default) and b) remove duplicates (in case you added a product to your default as well as multi-store, because then the same product will have a row for every store).

The cleanup, while not necessary, is recommended. You can go by without doing it, but if you have hundreds of useless rows in the database, it’ll only slow things down and effect performance. Delete them to make your site faster.

Note: You can use this extension to Bulk move products, categories and manufacturers between stores. It’ll, however, not delete duplicates.

Update Store ID for all existing Products

The table to edit is oc_product_to_store, the column is store_id. We are going to delete duplicates first and then update all products to link them to Default store.

Show all Products that are duplicates and are not linked to Default store

SELECT * FROM `oc_product_to_store` WHERE `product_id` = `product_id` AND `store_id` != 0;

Delete duplicates

DELETE FROM `oc_product_to_store` WHERE `product_id` = `product_id` AND `store_id` != 0;

Link all products to Default store

UPDATE `oc_product_to_store` SET `store_id` = 0 WHERE `store_id` != 0;

If you get

# MySQL returned an empty result set (i.e. zero rows).

that’s fine. It means that after deleting the duplicates, there were no products that didn’t already link to the Default store.

Update Store ID for all existing Categories

The table to edit is oc_category_to_store, the column is store_id.

Show all Categories that are duplicates and are not linked to Default store

SELECT * FROM `oc_category_to_store` WHERE `category_id` = `category_id` AND `store_id` != 0

Delete them

DELETE FROM `oc_category_to_store` WHERE `category_id` = `category_id` AND `store_id` != 0

Link all Categories to Default store

UPDATE `oc_category_to_store` SET `store_id` = 0 WHERE `store_id` != 0;

Update Store ID for all existing Manufacturers

The table to edit is oc_manufacturer_to_store, the column is store_id.

Show all Manufacturers that are duplicates and are not linked to Default store

SELECT * FROM `oc_manufacturer_to_store` WHERE `manufacturer_id` = `manufacturer_id` AND `store_id` != 0

Delete them

DELETE FROM `oc_manufacturer_to_store` WHERE `manufacturer_id` = `manufacturer_id` AND `store_id` != 0

Link all Manufacturers to Default store

UPDATE `oc_manufacturer_to_store` SET `store_id` = 0 WHERE `store_id` != 0;

Update Store ID for all existing Information pages

The table to edit is oc_information_to_store, the column is store_id.

Show all Information pages that are duplicates and are not linked to Default store

SELECT * FROM `oc_information_to_store` WHERE `information_id` = `information_id` AND `store_id` != 0

Delete them

DELETE FROM  `oc_information_to_store` WHERE  `information_id` =  `information_id` AND  `store_id` !=0

Link all Information pages to Default store

UPDATE `oc_information_to_store` SET `store_id` = 0 WHERE `store_id` != 0;

Get everything done in one step

The following code deletes duplicates and updates _storeid for all products, categories, manufacturers and information in one go. Only use this if you understand everything i have explained above, are confident in what you are doing and have a backup that you can restore if anything goes wrong.

DELETE FROM `oc_product_to_store` WHERE `product_id` = `product_id` AND `store_id` != 0;
DELETE FROM `oc_category_to_store` WHERE `category_id` = `category_id` AND `store_id` != 0;
DELETE FROM `oc_manufacturer_to_store` WHERE `manufacturer_id` = `manufacturer_id` AND `store_id` != 0;
DELETE FROM `oc_information_to_store` WHERE  `information_id` =  `information_id` AND  `store_id` !=0;

UPDATE `oc_product_to_store` SET `store_id` = 0 WHERE `store_id` != 0;
UPDATE `oc_category_to_store` SET `store_id` = 0 WHERE `store_id` != 0;
UPDATE `oc_manufacturer_to_store` SET `store_id` = 0 WHERE `store_id` != 0;
UPDATE `oc_information_to_store` SET `store_id` = 0 WHERE `store_id` != 0;

That’s it. You should now have all existing products, categories, manufacturers and information linked to your Default store, have no duplicates and gotten rid of your multi-store.