Component : Database

Description

This component is provided by the database upgrade.

The database component is primarily useful to work with “full” item stacks, including NBT tags, which are (by default) not available to Lua scripts (to avoid exploits / breaking of other mods' gameplay). Some components allow specifying item stacks by instead specifying the address of a database component, and slot the item stack is in that database - for example, the Export Bus driver for Applied Energistics 2 makes use of this functionality.

Component name: database.

Methods

• get(slot:number):tableGet the representation of the item stack stored in the specified slot.
• computeHash(slot:number):stringComputes a hash value for the item stack in the specified slot. This value is guaranteed to be the same for identical item stacks, allowing comparison of item stacks across a network (by comparing the hash values).
• indexOf(hash:string):numberGet the index of an item stack with the specified hash. Returns a negative value if no such stack was found.
• clear(slot:number):booleanClears the specified slot. Returns true if there was something in the slot before.
• copy(fromSlot:number, toSlot:number[, address:string]):booleanCopies an entry to another slot, optionally to another database. Returns true if something was overwritten.
• clone(address:string):number Copies the data stored in this database to another database with the specified address.

Example

            
-- https://ocdoc.cil.li/component:database
local component = require("component")
local sides = require("sides")
 
local db = component.database -- primary database component
local invcontrol = component.inventory_controller -- primary inventory controller
 
-- define slot numbers
dbSlot = 1
invSlot = 1
 
-- compare item inside remote inventory to item in first slot of database
if db.get(dbSlot).label == invcontrol.getStackInSlot(sides.north, invSlot).label then
	-- items match, do stuff with it. 
else
	-- items don't match, do nothing, or do something else.
end