ArangoDb - custom property name - json

Is there a way to get the value from key "· gc.alloc.rate"? Because the standard reference name after the dot returns an error.
...
"secondaryMetrics": {
"·gc.alloc.rate": {
"score": 502.22945873992126,
"scoreError": "NaN",
"scoreConfidence": [
"NaN",
"NaN"
],
...


You can either escape the attribute name with backticks or forward ticks, or use the bracket notation and a quoted string:
secondaryMetrics.`·gc.alloc.rate`
secondaryMetrics.´·gc.alloc.rate´
secondaryMetrics['·gc.alloc.rate']
secondaryMetrics["·gc.alloc.rate"]
https://www.arangodb.com/docs/stable/aql/fundamentals-syntax.html#names

Related

Regex Operation to Extract html Strings

I have the following html code:
'"height": { "#type": "QuantitativeValue", "value": "6-1" },\n
"weight": {"#type": "QuantitativeValue", "value": "195 lbs" }\n}\n'
I want to create a Regex that'll extract the height and weight values (6-1 and 195 lbs). What re expression can do this?

If you don't have anything else with the pattern "value": "", then just use:
value":\s"?(.*)"
https://regex101.com/r/clWVkg/1
If you do, then you can specify that you only want the values from height and weight caught:
(height|weight).*"value":\s"?(.*)"
https://regex101.com/r/5ShdKO/1
This will check for the word height or weight first, then ignore everything until value before doing a lazy catch all to capture the value. You should be able to extract the value by extracting the group.

JSON Schema - allow null with regex pattern

Would like to allow null on an optional date property where the date format is validated with a regex expression. Is this even possible?
"dateOfRetirement": {
"description": "Optional. Format: yyyy-MM-dd.",
"type": ["string", "null"],
"pattern": "^\\d{4}-\\d{2}-\\d{2}$"
}

To get the regular syntax for that you have to add a condition to your regex.
Your regex will get (assuming your regex syntax has no error!):
^(\\d{4}-\\d{2}-\\d{2}|null)$
Steps done:
incapsulate the normal regex with brackets (())
add an or-operator to the regex (|)
add the second validation for null to the regex after the or-operator
In the end the regex will allow a-valid-date-format or null as text.

I don't think that will work when "column": null.
It will only account for "column": "null" in regex

What do I call the object-hierarchical "path" of JSON attributes / properties / members and what is their standardized name?

Consider I have following typed JSON objects:
Parent: {
"field1" : "Value of field1"
"fieldC" : {Child}
}
Child: {
"field2" : "Value of field2"
}
Q: What do I call field1 and field2?
Just Strings?
Q: What to i call the "path" fieldC.field2?
Accessor path?
Field path?
Member hierarcy path?

field1 and field2 are just strings.
[anything, ..., ... ] is just an array, so the elements of an object.
and then you have 0-9 (with decimals, negative, positive or with e), true/false and null, as numeric values, boolean and nullvalue
{Child} is an object. I don't think it's called path (I'd say that's opinion-based). maybe field-path, but it's rather a child-object. the key is a string and the value is an object/array/string/bool/null/numeric or decimal
all the possibilities e.g.:
{
"string": "string-value",
"nulltype": null,
"child_object": {
"boolean": true,
"any_decimal_int": -1.5e3
},
"array_values":[
{
"any_value": true
},
{
"any_value": false
}
]
}
of course you can combine more and have unlimited child-objects and lists :)

jsonapi.org seems to refer field1,fieldC,and field2 as member names, which I find much more descriptive than just 'Strings'.
As mentioned in my comment to first answer, I guess I'll personally be using (hierarchical) property path or just (object) member hierarchy while referring to 'writing open' the object-hierarchical property/attribute/member 'path' such as fieldC.field2. Seems to be alot of room for interpretation in that. : ]

Does JSON grammar allow bare labels for elements? and are single quotes allowed?

After examining the JSON.org railroad (grammar) definition, it appears that the label and value pair for an element ( label : value ) requires quotes around the labels. Are quotes required always, or are they allowed to be omitted from simple words?
Example - this appears to be legal,
{ "vehicle" : { "type" : "truck", "year" : 1954, "make" : "ford" } }
Example - would this be legal?
{ vehicle : { type : "truck", year : 1954, make : "ford" } }
Also, are single quotes (') allowed, or only double quotes (")? Example,
{ 'vehicle' : { 'type' : 'truck', 'year' : 1954, 'make' : 'ford' } }
Many languages allow labels to be bare, and Ruby (for example) allows symbols to be prefixed by colon (:), example,
:fruit

Yes, according to the official JSON spec double quotes (and only double quotes) are required around every string, including object keys.
This is just one reason why JSON is a subset of the Javascript object literal notation, not a complete implementation.

JSON syntax is a subset of the JavaScript object notation syntax:
•Data is in name/value pairs
•Data is separated by commas
•Curly braces hold objects
•Square brackets hold arrays
I think - http://www.w3schools.com/json/json_syntax.asp will calrify your questions.

Perl Decode JSON - Not an ARRAY referencce

Getting error "Not an ARRAY reference" when trying to print my hash. Not sure where I am going wrong. IS there a way to print the decoded json in such a way that it makes identfying the hash elements easier?
use JSON qw( decode_json );
my $owm_json= <<'__EOI__';
{"cod":"200","city":{"id":"4270936","name":"Bazine","coord":{"lon":-99.6935,"lat":38.4421},"country":"United States of America","population":0},"cnt":65,"model":"OWM","list":{"0":{"dt":1390615200,"main":{"temp":39.63,"temp_min":39.69,"temp_max":43.7,"pressure":950.95,"humidity":62.4},"weather":[{"id":803,"main":"Clouds","description":"broken clouds","icon":"04n"}],"clouds":{"all":73,"low":0,"middle":6,"high":72},"wind":{"speed":15.98,"deg":269,"gust":13.8},"sys":{"pod":"n"}},"1":{"dt":1390626000,"main":{"temp":40.89,"temp_min":39.69,"temp_max":43.7,"pressure":951.79,"humidity":54.7},"weather":[{"id":803,"main":"Clouds","description":"broken clouds","icon":"04n"}],"clouds":{"all":82,"low":0,"middle":3,"high":82},"wind":{"speed":16.78,"deg":290,"gust":16.5},"sys":{"pod":"n"}},"2":{"dt":1390636800,"main":{"temp":41.45,"temp_min":40.91,"temp_max":41.72,"pressure":952.77,"humidity":47.7},"weather":[{"id":802,"main":"Clouds","description":"scattered clouds","icon":"03n"}],"clouds":{"all":35,"low":0,"middle":0,"high":35},"wind":{"speed":16.63,"deg":314,"gust":18.7},"sys":{"pod":"n"}},"3":{"dt":1390647600,"main":{"temp":39.81,"temp_min":39.83,"temp_max":41.72,"pressure":953.7,"humidity":48.9},"weather":[{"id":802,"main":"Clouds","description":"scattered clouds","icon":"03n"}],"clouds":{"all":32,"low":0,"middle":0,"high":32},"wind":{"speed":14.13,"deg":314,"gust":16.5},"sys":{"pod":"n"}},"4":{"dt":1390658400,"main":{"temp":40.51,"temp_min":38.5,"temp_max":40.53,"pressure":954.95,"humidity":50.3},"weather":[{"id":801,"main":"Clouds","description":"few clouds","icon":"02d"}],"clouds":{"all":23,"low":0,"middle":0,"high":23},"wind":{"speed":12.79,"deg":318,"gust":13.9},"sys":{"pod":"d"}},"5":{"dt":1390669200,"main":{"temp":51.67,"temp_min":38.5,"temp_max":51.66,"pressure":955.03,"humidity":44.3},"weather":[{"id":801,"main":"Clouds","description":"few clouds","icon":"02d"}],"clouds":{"all":18,"low":0,"middle":0,"high":18},"wind":{"speed":14.49,"deg":348,"gust":10.1},"sys":{"pod":"d"}},"6":{"dt":1390680000,"main":{"temp":54.99,"temp_min":51.75,"temp_max":55,"pressure":952.14,"humidity":40.3},"weather":[{"id":800,"main":"Clear","description":"sky is clear","icon":"01d"}],"clouds":{"all":1,"low":0,"middle":0,"high":1},"wind":{"speed":8.45,"deg":326,"gust":7.5},"sys":{"pod":"d"}},"7":{"dt":1390690800,"main":{"temp":46.15,"temp_min":45.82,"temp_max":55.35,"pressure":950.37,"humidity":53},"weather":[{"id":800,"main":"Clear","description":"sky is clear","icon":"02d"}],"clouds":{"all":10,"low":0,"middle":0,"high":10},"wind":{"speed":5.05,"deg":233,"gust":3.3},"sys":{"pod":"d"}},"8":{"dt":1390701600,"main":{"temp":45.1,"temp_min":45.1,"temp_max":47.71,"pressure":948.92,"humidity":53.8},"weather":[{"id":800,"main":"Clear","description":"sky is clear","icon":"01n"}],"clouds":{"all":0,"low":0,"middle":0,"high":0},"wind":{"speed":12.77,"deg":235,"gust":9.8},"sys":{"pod":"n"}},"9":{"dt":1390712400,"main":{"temp":43.43,"temp_min":43.41,"temp_max":47.71,"pressure":947.31,"humidity":56.4},"weather":[{"id":800,"main":"Clear","description":"sky is clear","icon":"01n"}],"clouds":{"all":0,"low":0,"middle":0,"high":0},"wind":{"speed":14.21,"deg":243,"gust":12.5},"sys":{"pod":"n"}},"10":{"dt":1390723200,"main":{"temp":41.38,"temp_min":41.43,"temp_max":43.41,"pressure":946.75,"humidity":59},"weather":[{"id":800,"main":"Clear","description":"sky is clear","icon":"01n"}],"clouds":{"all":0,"low":0,"middle":0,"high":0},"wind":{"speed":14.52,"deg":257,"gust":13.9},"sys":{"pod":"n"}},"11":{"dt":1390734000,"main":{"temp":39.83,"temp_min":39.4,"temp_max":43.41,"pressure":946.52,"humidity":56.8},"weather":[{"id":800,"main":"Clear","description":"sky is clear","icon":"01n"}],"clouds":{"all":0,"low":0,"middle":0,"high":0},"wind":{"speed":11.66,"deg":321,"gust":11.7},"sys":{"pod":"n"}},"12":{"dt":1390744800,"main":{"temp":41.22,"temp_min":39.16,"temp_max":41.25,"pressure":947.87,"humidity":50.3},"weather":[{"id":800,"main":"Clear","description":"sky is clear","icon":"01d"}],"clouds":{"all":0,"low":0,"middle":0,"high":0},"wind":{"speed":9.37,"deg":327,"gust":8},"sys":{"pod":"d"}},"13":{"dt":1390755600,"main":{"temp":51.73,"temp_min":39.16,"temp_max":51.76,"pressure":947.62,"humidity":34.6},"weather":[{"id":800,"main":"Clear","description":"sky is clear","icon":"01d"}],"clouds":{"all":0,"low":0,"middle":0,"high":0},"wind":{"speed":11.36,"deg":346,"gust":7.7},"sys":{"pod":"d"}},"14":{"dt":1390766400,"main":{"temp":53.58,"temp_min":51.85,"temp_max":53.64,"pressure":945.56,"humidity":30.5},"weather":[{"id":800,"main":"Clear","description":"sky is 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clouds","icon":"04d"}],"clouds":{"all":100,"low":44,"middle":100,"high":0},"wind":{"speed":10.04,"deg":14,"gust":5.9},"sys":{"pod":"d"}},"21":{"dt":1390842000,"main":{"temp":23.4,"temp_min":20.01,"temp_max":23.4,"pressure":965.27,"humidity":17.9},"weather":[{"id":804,"main":"Clouds","description":"overcast clouds","icon":"04d"}],"clouds":{"all":100,"low":52,"middle":100,"high":0},"wind":{"speed":6.83,"deg":6,"gust":4.2},"sys":{"pod":"d"}},"22":{"dt":1390852800,"main":{"temp":25.48,"temp_min":23.4,"temp_max":25.54,"pressure":963.17,"humidity":17.4},"weather":[{"id":804,"main":"Clouds","description":"overcast clouds","icon":"04d"}],"clouds":{"all":100,"low":44,"middle":100,"high":0},"wind":{"speed":4.73,"deg":346,"gust":3.5},"sys":{"pod":"d"}},"23":{"dt":1390863600,"main":{"temp":24.8,"temp_min":23.4,"temp_max":25.63,"pressure":963.34,"humidity":19.6},"weather":[{"id":804,"main":"Clouds","description":"overcast 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__EOI__
my $decoded = decode_json($owm_json);
print $decoded->{list}[0]->{weather}[0]->{description};

Your string $owm_json isn't a valid Perl string. From the short segment:
"{"cod":"200","city":{"id":"4270936","name":
This should actually be:
"{\"cod\":\"200\",\"city\":{\"id\":\"4270936\",\"name\":
You need to escape the inner quotation marks. Try putting use strict at the beginning of the script and that should have caught this error.
Update from comments:
Looking at your JSON data, you do have an incorrect access to the descpiption field. Here's the section you are trying to display in your example:
"list" : {
"0" : {
"weather" : [{
"id" : 803,
"main" : "Clouds",
"description" : "broken clouds",
"icon" : "04n"
}
],
Notice that after "list" you have "0", not an array reference which would use the [] characters. In your script, after {list} use {0} and not [0] and that should fix your issue:
print $decoded->{list}{0}{weather}[0]{description};

The value of list is a hash (...,"list":{"0":{...},...), but you try to dereference is with ->[0] which is an array dereference.
You want:
$decoded->{list}{0}{weather}[0]{description}
instead of
$decoded->{list}[0]{weather}[0]{description}