...
Operator | Meaning | Example | ||
|---|---|---|---|---|
= | Equal |
| ||
> | Greater than |
| ||
>= | Greater than or equal to |
| ||
< | Smaller than |
| ||
<= | Smaller than or equal to |
| ||
!= | not equals to |
|
Advanced AQL operatorsoperators
matches
matches operator is used in WHERE clause. It has left expression. This operator needs left operand and right operand. Left operand is an AQL identified path. Right operand is enclosed within curly braces. Right operand of matches operator has three forms:
- type of constraint ADL (cADL): this type of matches right operand can be a value list , a value range,
These advanced operators are not yet supported by the grammar. The operator syntax is borrowed from ADL specifications. These are proposed to improve the richness and flexibility of AQL so that AQL syntax supports more complicated query scenarios.
...
This is an example of a terminology URI:
...
...
EHR URI
to be continued...
...
Value range leaf data is enclosed within curly braces after matches operator. It is only used in AQL WHERE clause to specify a criteria within a range. The syntax is similar as intervals of ordered primitive types (detailed in Section 4.5.2) in , adl.pdf. Some examples:
| Code Block |
|---|
matches {|3.0..5.0|} // means 3.0 <= x <=5.0
matches {|<8|} // means x<8 x<8
|
AQL structure
Overview
AQL structure has been briefly introduced in Section 2.2. This section introduces AQL structure in details.
...