MQL-Tutorial

MQLMQL TutorialUlrik PetersenOctober 8, 2003What is Emdros?➲ Emdros is a text database engine.➲ Emdros deals with “annotated text”, or “analyzed text”.➲ Emdros is especially good at storing and retrieving syntactic analyses of text.➲ Emdros has a powerful query language (MQL).MQL Tutorial➲What follows is a short tutorial on MQL.➲The examples are mostly from a syntacticdatabase of the Hebrew Bible (Tanakh).MQL Tutorial➲MQL is centered around “object blocks” surrounded by [square brackets]:[Clause]Finds cla use-objectsMQL Tutorial – Structures➲ Object blocks can be: ● Nested or● Consecutive or● Separated by arbitrary str etches➲ These are the basic structural relationships that can obtain between object b locks.➲ They are used in the “basic principle o f MQL” (coming up next...)MQL Tutorial – Basic principle➲ Basic principle in MQL: The structure of the query mirrors the structure of the objects found by the query in terms of nesting, consecutiveness, and arbitrary space.(Examples follow..)MQL Tutorial - Nesting➲ If object block A (e.g., Phrase) is nested inside object block B (e.g., Clause), then the object found by A must be wholly contained in the object found by B:[Clause[Phrase]]Finds a phrase inside a clause.MQL Tutorial - Sequence➲ If object block B is consecutive to object block A, then the object found by B must be consecutive to the ob-ject found by A:[Word][Word]Finds two adjacent wordsMQL Tutorial – ...