Project Items
Project items in the Design view and the connections between them make up the graph (Directed Acyclic
Graph, DAG) that is executed when the 
or 
buttons are pressed.
See Executing Projects for more information on how a DAG is processed by Spine Toolbox. Those interested in looking under the hood can check the Project Item Development section.
Project Item Properties
Each project item has its own set of properties. You can view and edit them by selecting a project
item in the Design View. The properties are displayed in the Properties dock widget on the main
window. Project item properties are saved into the project save file (project.json), which can be
found in <proj_dir>/.spinetoolbox/ directory, where <proj_dir> is your current project
directory.
In addition, each project item has its own directory in the <proj_dir>/.spinetoolbox/items/
directory. You can quickly open the project item directory in a file explorer by clicking the
button located in the upper right corner of each Properties form.
Project Item Descriptions
The following items are currently available:
Data Connection 
A Data connection item provides access to data files. The item has two categories of files: references connect to files anywhere on the file system or on remote (non-Spine) databases while data files reside in the item’s own data directory.
Data Store 
A Data store item represents a connection to a (Spine) database. Currently, the item supports sqlite and mysql dialects. The database can be accessed and modified in Spine db editor available by double-clicking a Data store on the Design view, from the item’s properties, or from a right-click context menu.
Data Transformer 
Data transformers set up database manipulators for successor items in a DAG. They do not transform data themselves; rather, Spine Database API does the transformations configured by Data transformers when the database is accessed. Currently supported transformations include entity class and parameter renaming as well as value transformations.
Exporter 
Exporter outputs database data into tabulated file formats that can be consumed by Tool or be used by external software for analysis. See Importing and Exporting Data for more information.
Importer 
This item provides the user a chance to define a mapping from tabulated data such as comma separated values or Excel to the Spine data model. See Importing and Exporting Data for more information.
Merger 
A Merger item transfers data between Data Stores. When connected to a single source database, it simply copies data from the source to all output Data Stores. Data from more than one source gets merged to outputs.
Tool 
Tool is the heart of a DAG. It is usually the actual model to be executed in Spine Toolbox but can be an arbitrary script, executable or system command as well. A Tool is specified by its specification.
