MYSQL Rows Replaced

lstables

I have come across a strange problem when recording data to the database.

I have 3 tables product_category, product_subcategory, product_description. If the product subcategory field matches the same data as one already in the table it get replaced. For example

product_category product_subcategory product_description
------------------|---------------------|-------------------
systems | main | a description
power | supplies | a description
| |

As you can see i have a subcategory call main. If I create a new category i.e electrical and set the subcategory to main the systems row would get replaced by electrical. If I named the Subcategory main2 the the entry would work as normal.

Is this something I am doing wrong? or simply a bug that needs fixing

Thanks

admin

What are the unique keys of your tables?