The Data Layer is a simplified model of the HORIZON database. It can be thought of as a wrapper around the complex set of tables and views that make up the database. It is used by report writers and LIMS Administrators to gain access to the raw underlying data without having to know how to navigate the database.
The Data Layer is populated on demand for a specific HORIZON object, such as a workorder or sample. The content of the Data Layer will then include all HORIZON data pertaining to this particular object. Furthermore, this content has been filtered through the same set of application rules and logic enforced by the HORIZON LIMS. Only content pertinent to this object is included. Think of it as an exclusive private instance of the LIMS where your object is the only content.
The Data Layer can be easily populated directly through the “where” clause of a simple SQL “select” statement. You will not need to make any complicated “joins” to navigate the data. You can select the attributes that you are interested in from the Data Layer just as easy as selecting columns from a table.
The Data Layer is implemented as a set of Oracle user-defined objects. Each object represents a unique concept modeled in the HORIZON LIMS. The objects are populated with data for the specific HORIZON object you are interested in, e.g. workorder, sample, batch, etc. These objects are nested together in an easily understood hierarchal model. This structure is a simplistic presentation of data that eliminates the complexities of the database, yet preserves all the application logic that binds the data together. The nesting of the objects provides the context linking without having to explicitly join anything together.