Object Query Language (OQL) - Syntax Reference	Contents
	OQL built-In Function Reference
	The OQL Filter/Expression Editor

ReportWeaver uses the Object Query Language as defined by the ODMG standardisation organisation.

An ReportWeaver filter or formula is an OQL predicate. A predicate is the where part of an OQL query. A general OQL query has the form:
select this from that where predicate

In ReportWeaver the variable name of the outermost scope can be written as this and the type of this is either the element type of the collection to which the predicate is applied to or the type of the single object where the predicate is evaluated.

Example:
Assume there is a collection of Students, that you want to report on. To select all students whose name starts with a you would write:
name like "a*"
This is equivalent to the general OQL query:
select * from Students this where name like "a*"

ReportWeaver implements a subset of OQL. The parts of OQL that are specified interactively in ReportWeaver such as aggregation, sorting, grouping, and structure building have been omitted. For the semantics of the grammar rules below please see the ODMG standard which is available through the ODMG

The OQL implementation of ReportWeaver provides a number of standard functions that can be used within predicates or formulas.

Here is an overview of the OQL predicate syntax as implemented by ReportWeaver:

1. Basic
   query ::=nil | true | false | this | env
   query ::=integer | float | character | string
   query ::=(query)
2. Simple Expression (see 4.9.5)
   query ::=query + query
   query ::=query - query
   query ::=query * query
   query ::=query / query
   query ::=- query
   query ::=query mod query
   query ::=abs (query)
   query ::=query || query // string concatenation also written as +
3. Comparison Expression
   query ::=query comparison_operator query
   query ::=query like string_literal
   comparison_operator ::==
   comparison_operator ::=!=
   comparison_operator ::=>
   comparison_operator ::=<
   comparison_operator ::=>=
   comparison_operator ::=<=
4. Boolean Expression
   query ::=not query
   query ::=query and query
   query ::=query or query
5. Access Expression
   query ::=query dot attribute_name
   query ::=query dot operation_name(query {,query}) // not implemented
   dot ::=. | ->
   query ::=* query // not implemented
   query ::=query [query]
   query ::=query [query:query] //sub list
   query ::=query [query .. query] //sub list
   query ::=first (query)
   query ::=last (query)
   query ::=function_name([query {,query}]) // implemented for a number of predefined functions
6. Collection Expression
   query ::=for all identifier in query: query
   query ::=exists identifier in query: query
   query ::=exists(query) // not implemented
   query ::=unique(query) // not implemented
   query ::=query in query // not implemented
   query ::=query comparison_operator quantifier query // not implemented
   quantifier ::= some | any | all
   query ::=count (query)
   query ::=count ( * ) // not implemented
   query ::=sum (query) // not implemented
   query ::=min (query) // not implemented
   query ::=max (query) // not implemented
   query ::=avg (query) // not implemented
7. Select Expression // not implemented
   There is a non standard short hand notation for a nested select expression:
   filter identifier in query: query
   This is equivalent to;
   select * from query identifier where query
8. Set Expression
   query ::=query intersect query // also written as query * query
   query ::=query union query // also written as query + query
   query ::=query except query // also written as query / query
9. Conversion Expression
   query ::=listtoset (query) // not implemented
   query ::=element (query) // not implemented
   query ::=distinct(e) // not implemented
   query ::=flatten (query) // not implemented
   query ::=(class_name) query

Related topics:

•  OQL editor
•  Built-in function reference
•  Variable editor
•  Table wizard
•  Adding Computed Fields to Views

The OQL Filter/Expression Editor

Contents

OQL built-In Function Reference