Component/database

Component: Database

This component is provided by the database upgrade.

Component name: `database`.

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.

Callbacks:

• `get(slot:number):table`

Get the representation of the item stack stored in the specified slot.

• `computeHash(slot:number):string`

Computes 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):number`

Get the index of an item stack with the specified hash. Returns a negative value if no such stack was found.

• `clear(slot:number):boolean`

Clears the specified slot. Returns true if there was something in the slot before.

• `copy(fromSlot:number, toSlot:number[, address:string]):boolean`

Copies 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 Use:

```lua 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 ```

Components	Category	Documentation
Components	Core Components	3D Printer - Abstract Bus - Access Point - Chunkloader - Computer - Crafting - Data Card - Database - Debug - Drone - Drive - EEPROM - Experience - Filesystem - Generator - Geolyzer - GPU - Hologram - Internet - Inventory Controller - Leash - Microcontroller - Modem - Motion Sensor - Navigation - Net Splitter - Piston - Redstone - Redstone in Motion - Robot - Screen - Sign - Tank Controller - Tractor Beam - Transposer - Tunnel - World Sensor
	Others	Component Access - Signals
	Cross-Mod Integration	Applied Energistics