Using eSQL
About this Guide
The guide describes the eSQL language and is aimed at administrators who have been trained accordingly by OPTIMAL SYSTEMS. In order to use eSQL, you should already be familiar with the yuuvis® object type system and the SQL database query language. Knowledge of yuuvis® management-studio is also highly recommended.
About yuuvis® RAD and eSQL
With yuuvis® RAD, OPTIMAL SYSTEMS provides an ECM platform that is tailored to meet the requirements of digital information management with modern technologies. In contrast to many other systems, this not only involves data filing, but rather focuses on the integration of information into dynamic company processes. The platform enables companies and organizations to turn available data and information into useful knowledge.
These challenges have been firmly anchored in the basic architecture of yuuvis® RAD. yuuvis® RAD is a system that is able to react extremely flexibly to constantly changing requirements from the business context, in addition to the compliance aspects and usual requirements for data management. In addition to other modern technologies, yuuvis® RAD provides:
- A powerful object type system for more realistic and object-oriented modeling of business objects
- Project-specific relation types for structuring typed links between the managed objects
- A powerful language anchored in the system for querying objects and relations: eSQL
Based on these characteristics, yuuvis® RAD can also be denoted as an object-relational database.
The eSQL language and how it is embedded into the overall architecture are presented in this guide. This guide can also be used by system architects and system administrators as a reference for everyday use.
eSQL in a Nutshell
eSQL offers users and administrators who have prior knowledge of the widely used SQL language a simple way of accessing all relevant data and information of the ECM system.
eSQL is a simple query language. It is not possible to insert, delete, or change data.
All important information about the data saved in the ECM system can be queried within the data model using eSQL. No knowledge of the actual data storage form is necessary for this.
eSQL extends SQL with object-oriented aspects. yuuvis® RAD's object-oriented modeling approach provides the option to model in a far more practice-oriented way, as derivatives of object types can also be depicted within the data model.
eSQL enables queries to be depicted within the class hierarchy. In addition to the object types from the customer's data model, the yuuvis® RAD object type system also provides important classes for Enterprise Content Management systems that can be used in the queries.
eSQL takes all security aspects into account. An eSQL query only returns the data and objects that are visible for the querying user account for each authorization model set up. As these visibility restrictions are rules-based, unlike in conventional SQL databases, and can even be applied to individual objects and records, unauthorized accesses to the system via queries is not possible.
eSQL offers special language elements in order to be able to form queries easily in object type system logic for all important aspects of the object type system, such as version control, inheritance, and links between objects and relations, for example.
eSQL hides the implementation details of the storage, so that system architects and specialist users can move within their data model without having to consider the underlying technology. The ECM application spectrum can therefore be significantly widened, as neither the interfaces nor the programming logic need to be adapted in order to access information outside of the standard.
Compared to the SQL standard, eSQL offers the extended option of including relations between objects set up in the system or project in the queries. This simplifies the language, as the technical details for generating relations (e.g., foreign keys) can be automatically resolved and used.
eSQL is deeply embedded in yuuvis® RAD and is used continuously by the system itself. eSQL is therefore also available on all important interfaces for integrating other systems. The object-oriented approach not only provides the option of accessing pure data in the form of column values, as is common in conventional database systems, but also accessing objects immediately through the interfaces. The system thus already converts the data into convenient programming interfaces.
eSQL Application Areas
eSQL is the language used consistently in yuuvis® RAD for determining user data and information. All queries to the system are formulated and executed internally in eSQL. This basic principle provides the basis for a future-proof and extendable platform, which can be used to depict current and future requirements.
eSQL can also be used by system architects in order to adapt yuuvis® RAD to special project requirements and thus benefit from the full performance of the system. This can be used in the following situations, for example, in order to:
- Formulate special queries to the system
- Perform special queries within the yuuvis® RAD development environment in internal scripts that are connected to interface elements
- Check inputs or the plausibility within the business logic
- Link rights in the rights system to conditions and thus grant or revoke them in a targeted manner
- Easily extract and further process data from the ECM system on interfaces in business intelligence applications