2.2.11 Using HQL standard
By specifying HQL (Hitachi Query Language) for HQL::filter, you can filter the target data. A collection refers to data to be filtered.
Use UTF-8 encoding and encode characters and symbols that cannot be expressed as a URL.
Format
To define a collection of a resource request, use the following expressions:
expression ::= "(" expression ")" | binary-expression | expression junction expression
junction ::= ( "and" | "or" )
binary-expression ::= (compare-expression | tuple-expression)
compare-expression ::= name-expression compare-operation value-expression
name-expression ::= property-name | "[" property-name "]"
compare-operation ::= ( "eq" | "=" | "ne" | "<>" | "!=" | "gt" | ">" | "lt" | "<" | "ge" |">=" | "le" |"<=" | "starts" | "ends" )
value-expression ::= ( string-expression | number-expression |Boolean-expression )
string-expression ::= "'" ([^'] | [']{2})* "'"
number-expression::= ( "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" )+
Boolean-expression::= "true" | "false" |"TRUE" | "FALSE"
tuple-expression ::= name-expression tuple-operation tuple-value-expression
tuple-value-expression ::= "[" value-expression ("," value-expression)* "]"
tuple-operation ::= ( "in" | "not in" )
property-name is a member name defined in a resource.
value-expression displays whether the expression is a string expression, number expression, or Boolean expression. This value is different from the actual data type of the member defined in a resource.
The following table describes the relationship between the data types and expression formats.
Data type |
Expression format |
|---|---|
integer/long |
number-expression |
enum |
string-expression |
string |
string-expression |
ISO8601String |
string-expression |
URLString |
string-expression |
boolean |
Boolean-expression |
The following table lists and describes the operators supported by HQL in preferential order.
Operator |
Description |
Specifiable data type |
Priority |
|---|---|---|---|
eq |
Equal |
number-expression, string-expression (string, enum), Boolean-expression |
1 |
ne |
Not equal |
number-expression, string-expression (string, enum), Boolean-expression |
1 |
gt |
Greater than |
number-expression, string-expression (string, enum) |
1 |
lt |
Smaller than |
number-expression, string-expression (string, enum) |
1 |
ge |
Equal or greater than |
number-expression, string-expression (string, enum) |
1 |
le |
Equal or smaller than |
number-expression, string-expression (string, enum) |
1 |
starts# |
Start value |
string-expression (string, excluding ISO8601String) |
1 |
ends# |
End value |
string-expression (string, excluding ISO8601String) |
1 |
in |
Included |
number-expression, string-expression (string, enum), Boolean-expression |
1 |
not in |
Not included |
number-expression, string-expression (string, enum), Boolean-expression |
1 |
and |
Both true |
compare-expression, tuple-expression |
2 |
or |
Either of them true |
compare-expression, tuple-expression |
3 |
- #
The operators are not case sensitive.
Usage example
The example below filters the specified line. If you want to specify a character string that cannot be expressed as a URL, use UTF-8 encoding and encode the character string.
- Before URL encoding:
...?HQL::filter=instanceID in [1000,1001,1002] and status = 'running'
- After URL encoding:
...?HQL::filter=instanceID%20in%20%5b1000%2c1001%2c1002%5d%20and%20status%20%3d%20%27running%27