Overview - AmericanManufacturingCohort/HR-CDM-Data-Transformation GitHub Wiki
The image below illustrates the 3 steps to perform the data transformation: 1) Data Selection, 2) Field Mapping, and 3) Data Loading

Step 1: Data Selection
We selected relevant variables from the data sources and created a base data set.
In this step, we itemized the variables in the two data sources and identified those that are similar to each other. Working from one data source to the other, we checked each variable by its name, description, and content and came up with a matching pair. Once paired, we then relabelled the variables with a new same name to make them consistent during the merging. We completed this step by creating a single "base" data set that consists of 29 elected variables.
Step 2: Field Mapping
We mapped the variables from the base data set to the HR-CDM table schemas and normalized the relationships
In this step, we looked at each HR-CDM table schema and fields and identified the appropriate variable from the base data set to fill out the target field. Once we produced the mappings, an ETL program would read those mappings, extract the value from the base data set and build the HR-CDM tables. The program will split the source data table into many tables and assign unique identifiers to identify the rows. We then maintained the integrity and consistency of the base data set by referencing the table relationships using the identifiers.
Step 3: Data Loading
We created an easy and consistent way to load the HR-CDM tables into different data storage platforms.
At the time of this writing, we created data loading functions in R and Python languages that will load CSV files to data frames. Other platforms will come as future work.