Hi, i want to delete some extra libraries from my koha system. Then, i could delete three from GUI; Koha-&gt; Administration-&gt; Libraries &amp; Groups. But, there are more two including default &quot;My library&quot;. Then i went to mysql an tried to delete those two library names, which are as sub-branch; but, i cannot delete those. Error shows:<br>

<i><b><br>mysql + #1451 - Cannot delete or update a parent row: a foreign key constraint fails</b></i><br clear="all"><br>-- <br>Best,<br>Zico<br>