hrq2mongoq lets you formulate MongoDB queries in a human readable way by transforming HRQs (human readably queries) into MongoDB queries.
and, or, nor and not=, >, <, =>, =<, either...or, both...and and ranges$existsstrings, numbers, date and time, booleans and objectIDsAs easy as npm can be:
$ npm install hrq2mongoqExample with mongoose:
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/test');
var Person = mongoose.model('Person', yourSchema);
var hrq2mongoq = require('hrq2mongoq');
var hrquery = 'city of person is Amsterdam and occupation of person is studying';
var hrsort = 'date of birth descending, surname and firstname';
var hrproj = 'firstname and surname'
var mongoq = hrq2mongoq.parse(hrquery);
// mongoq = { '$and':
// [ { 'person.city': 'Amsterdam' },
// { 'person.occupation': 'studying' } ] }
var mongos = hrq2mongoq.parse(hrsort);
// mongos = { 'birth.date': -1, 'surname': 1, 'firstname': 1}
var mongop = hrq2mongoq.parse(hrproj);
// mongop = { 'firstname': 1, 'surname': 1}
Person.find(mongoq, mongop).sort(mongos);
// firstname and surname of people studying in Amsterdam, sorted in descending order by date of birth and then in ascending order by surname and first nameexpression <- field vexpr
Selects the documents for which the field satisfies the single value expression vexpr.
Examples
Instead of providing one value expression, one can provide multiple one with on the two following operators.
both...and operatorexpression <- field both vexpr , ... , vexpr and vexpr
expression <- field : vexpr & ... & vexpr & vexpr
Selects the documents for which the field satisfies all the listed value
expressions.
Examples
either...or operatorexpression <- field either vexpr , ... , vexpr or vexpr
expression <- field : vexpr | ... | vexpr | vexpr
Selects the documents for which the field satisfies at least one of the
listed value expressions.
Examples
and operatorexpression <- expression and expression
expression <- expression & expression
Selects the documents for which both expressions are satisfied.
Examples
The keyword and must be surrounded by whitespace, where as the & symbol can be used without surrounding spaces.
or operatorexpression <- expression or expression
expression <- expression | expression
Selects the documents for which on of the two expressions is satisfied.
Examples
The keyword or must be surrounded by whitespace, where as the | symbol can be used without surrounding spaces.
nor operatorexpression ->expression nor expression
Selects the documents for which none of the two expressions are satisfied.
The keyword nor must be surrounded by whitespace and it doesn't have a corresponding symbol.
Examples
Currently the logical operators all have the same precedence and are right associative. So
a and b or c and d is interpreted as a and (b or (c and d))
This might be counter intuitive, so it is advised to always use parentheses ( )when combining logical operators.
One could write for example: ( a and b ) or ( c and d ).
Examples
A value expression vexpr defines a constraint on a field.
The following operators can be used:
vexpr <- is value
vexpr <- is not value
vexpr <- is greater than value
vexpr <- is less than value
vexpr <- is equal or greater than value
vexpr <- is equal or less than value
vexpr <- = value
vexpr <- != value
vexpr <- < value
vexpr <- > value
vexpr <- =< value
vexpr <- => value
As with the logical operators, the 'natural language' keywords must be surrounded by whitespace, where the symbols can be used without surrounding spaces. If it is needed to explain the semantics of these operators any further, you can contact the author to make a personal appointment in Switzerland. During a hike in the Alps he will most happily explain all the ins and outs about them.
vexpr <- ranges from value to value
vexpr <- {}= value - value
The range operator constraints the value to be within the specified range (inclusive).
Examples
vexpr <- starts with string
vexpr <- ends with string
vexpr <- contains string
vexpr <- matches regex_string
vexpr <- $start= string
vexpr <- $end= string
vexpr <- $contains= string
vexpr <- $regex= regex_string
All string matching is currently case sensitive.
The matches and regex= operators constraint the value to match the specified regular expression (Perl compatible).
Examples
vexpr <- exists
vexpr <- *
States that the field should exist.
Examples
vexpr <- does not exist
vexpr <- ^
States that the field should not exist.
Examples
sorting <- field [descending], field [descending], ..., field [descending]
sorting <- field [descending] and field [descending] and ... and field [descending]
projection <- field, field, ..., field
projection <- field and field and ... and field
Parsing sorting and projection expressions will return a JSON document which can be used with Mongo's cursor.sort(sort) and db.collection.find(query, projection) respectively.
Examples
field <- word
field <- word . word . ... . word
field <- word of word of ... of word
field <- quoted string
Fields of embedded documents can be specified by using dot notation . or the keyword of. If the field is given as a quoted_string only the dot notation can be used.
Please note there is a subtle semantical difference between the dot notation and the of keyword:
field . subfield means the subfield of the field in human language, whereas subfield of field means field.subfield in mongo language. Hoping you still understand my language.
Examples
A value can be one of the following datatypes:
value <- word
value <- quoted string
value <- number
value <- datetime
value <- boolean
value <- objectID
A word
$ : { } - + " ' = < > & | ! * ^ . ,Examples
A `quoted string is a sequence of characters surrounded by double quotes. Quotes within the string should be escaped.
string <- "a string with double quotes"
string <- "a string containing \"quotes\""
Examples
A number can be a signed integers or a float, for example -4567 or 42.314.
Examples
datetime <- yyyy - MM - dd
datetime <- yyyy - MM - dd hh : mm
datetime <- yyyy - MM - dd hh : mm : ss
Note that all three formats will internally be converted to a JavaScript Date object, which is the number of milliseconds from 1 January 1970 00:00:00 UTC.
Examples
A boolean can be represented by the keywords true and false.
Examples
An objectID is represented as 0x followed by 24 hexadecimal characters.
Examples
hrq2mongoq is developed and maintained by David de Bos.
Initial development was sponsored by dividat GmbH in Schindellegi, Switzerland.