The common way of obtaining data from a composite table file (.ctx) is performing queries using simple SQL statements or through esProc functions. The way becomes difficult, hard to code and unintelligible when a business task involves multi-table joins. To address the issue, esProc offers simple non-join Dimensional query syntax (Dimensional Query language). Statements written in this language are simply called DQL.
DQL adopts bus-based data models, which reduces coupling between tables and helps understand business data models. The language is particularly suitable for handling multi-table join queries.
This chapter aims to guide you through basic DQL query syntax.