php - Partial replace on a modified preorder tree traversal from script -

i have mptt (modified preorder tree traversal) this:

(taken sitepoint)

my real tree has thousands of nodes , more complex structure, simplification shows problem.

until moment, every time need change tree used shell script looks this:

#!/bin/bash mysql -umyuser -pmypass database < tree.sql 

and executes (tree.sql):

drop table if exists `tree`; create table `tree` (   `parent` varchar(32) default null,   `title` varchar(32) collate utf8_unicode_ci not null,   `lft` int(11) not null,   `rgt` int(11) not null ) engine=innodb default charset=utf8 collate=utf8_unicode_ci;  lock tables `tree` write; insert `tree` values (....),(....).... 

(note: use shell script because there multiple instalations of same php application in multiple servers , easy/fast way update them, if required can move update php).

but now, requirements state that:

1. food/meat branch exist
2. food/meat subtree must preserved because users can edit contents
3. other parts of tree must updated (food/fruit in case app agnostic structure).

so, given cannot execute drop table, need retrieve branch (food/meat) , insert tree after drop table, create table , insert table executed.

the question is: how retrieve branch shell? , how insert again? (note if it's not possible shell script can create 2 small php scripts, still have no idea of how branch , insert again, idea welcome)