Using Datamartist- blocks and connections
Data transformations are done in Datamartist by using data blocks that are placed on the canvas and connected together via connection stubs. The location of the stub on the block defines if it is an input or and output. Input stubs provide the data sets that the block will do its transformations on, and output stubs make the results of the transformation available for other blocks to use on their input stubs.
- Input Stubs - Left and Top sides of the block.
- Output Stubs - Right and Bottom sides of the block.
Preview mode- dashed lines
If blocks or connectors use dashed lines, this indicates that they do not contain all of the underlying data available, but only a preview of the data. This is done to make it possible to use very large data sets and not have performance issues while designing and manipulating the data blocks.
Putting new blocks on the canvas
New blocks can be placed onto the canvas by either dragging and dropping from the transform blocks tab at the upper left of the interface, or by right clicking either on the canvas or on an existing block.
Dragging and Dropping
Right clicking can be done either on the canvas, to insert any new block without connecting it to anything, or by clicking on an existing block on the canvas. When you click on an existing block, the right click menu will only include blocks that are compatible with the outputs of the selected block. When you use this option the blocks will be connected using default stubs.
Connecting blocks together
To connect blocks together, first select a stub on a block, and hold down the left mouse button. Now as you move the cursor, a line will follow it, and as you pass over stubs on other blocks, the cursor will indicate if the stub can be connected to the anchor stub you have selected. Depending on where the cursor is, the target stub selected will be highlighted.
Configuring or editing blocks
Each type of block performs a particular type of data transformation using the data provided by the connections on its input stubs- and then passes the result out to the next blocks in the chain through their output stubs. Blocks do not modify the data in the blocks connected to their inputs.
There are two ways to edit the configuration of a block, depending on the block type. Some blocks use dialog boxes for configuration, and others show controls right in the data viewer and configuration area when clicked upon. In both cases, right clicking the block and selecting edit will call up the controls.
In the example below, a combine block has been selected, and we can see in the data viewer and configuration area the controls for that blocks configuration are displayed, allowing us to modify how the block transforms the data.
Viewing Data in connectors and stubs
To view the data on a stub or in a connector select it by clicking. The data viewer will be called up in the data view/config pane. By selecting the data profiler tab () it is possible to see row counts by category which is useful for determining the distribution of values, and the existance of nulls or other potential issues.