class Sequel::Postgres::JSONBaseOp

The JSONBaseOp class is a simple container for a single object that defines methods that yield Sequel expression objects representing PostgreSQL json operators and functions.

In the method documentation examples, assume that:

json_op = Sequel.pg_json(:json)

Constants

EMPTY_STRING
GET
GET_PATH
GET_PATH_TEXT
GET_TEXT
IS_JSON
IS_JSON_MAP
IS_NOT_JSON
WITH_UNIQUE

Public Instance Methods

[](key) click to toggle source

Get JSON array element or object field as json. If an array is given, gets the object at the specified path.

json_op[1] # (json -> 1)
json_op['a'] # (json -> 'a')
json_op[%w'a b'] # (json #> ARRAY['a', 'b'])
    # File lib/sequel/extensions/pg_json_ops.rb
181 def [](key)
182   if is_array?(key)
183     json_op(GET_PATH, wrap_array(key))
184   else
185     json_op(GET, key)
186   end
187 end
Also aliased as: get
array_elements() click to toggle source

Returns a set of json values for the elements in the json array.

json_op.array_elements # json_array_elements(json)
    # File lib/sequel/extensions/pg_json_ops.rb
193 def array_elements
194   function(:array_elements)
195 end
array_elements_text() click to toggle source

Returns a set of text values for the elements in the json array.

json_op.array_elements_text # json_array_elements_text(json)
    # File lib/sequel/extensions/pg_json_ops.rb
200 def array_elements_text
201   function(:array_elements_text)
202 end
array_length() click to toggle source

Get the length of the outermost json array.

json_op.array_length # json_array_length(json)
    # File lib/sequel/extensions/pg_json_ops.rb
207 def array_length
208   Sequel::SQL::NumericExpression.new(:NOOP, function(:array_length))
209 end
each() click to toggle source

Returns a set of key and value pairs, where the keys are text and the values are JSON.

json_op.each # json_each(json)
    # File lib/sequel/extensions/pg_json_ops.rb
215 def each
216   function(:each)
217 end
each_text() click to toggle source

Returns a set of key and value pairs, where the keys and values are both text.

json_op.each_text # json_each_text(json)
    # File lib/sequel/extensions/pg_json_ops.rb
223 def each_text
224   function(:each_text)
225 end
extract(*a) click to toggle source

Returns a json value for the object at the given path.

json_op.extract('a') # json_extract_path(json, 'a')
json_op.extract('a', 'b') # json_extract_path(json, 'a', 'b')
    # File lib/sequel/extensions/pg_json_ops.rb
231 def extract(*a)
232   self.class.new(function(:extract_path, *a))
233 end
extract_text(*a) click to toggle source

Returns a text value for the object at the given path.

json_op.extract_text('a') # json_extract_path_text(json, 'a')
json_op.extract_text('a', 'b') # json_extract_path_text(json, 'a', 'b')
    # File lib/sequel/extensions/pg_json_ops.rb
239 def extract_text(*a)
240   Sequel::SQL::StringExpression.new(:NOOP, function(:extract_path_text, *a))
241 end
get(key)
Alias for: []
get_text(key) click to toggle source

Get JSON array element or object field as text. If an array is given, gets the object at the specified path.

json_op.get_text(1) # (json ->> 1)
json_op.get_text('a') # (json ->> 'a')
json_op.get_text(%w'a b') # (json #>> ARRAY['a', 'b'])
    # File lib/sequel/extensions/pg_json_ops.rb
249 def get_text(key)
250   if is_array?(key)
251     json_op(GET_PATH_TEXT, wrap_array(key))
252   else
253     json_op(GET_TEXT, key)
254   end
255 end
is_json(opts=OPTS) click to toggle source

Return whether the json object can be parsed as JSON.

Options:

:type

Check whether the json object can be parsed as a specific type of JSON (:value, :scalar, :object, :array).

:unique

Check JSON objects for unique keys.

json_op.is_json                 # json IS JSON
json_op.is_json(type: :object)  # json IS JSON OBJECT
json_op.is_json(unique: true)   # json IS JSON WITH UNIQUE
    # File lib/sequel/extensions/pg_json_ops.rb
267 def is_json(opts=OPTS)
268   _is_json(IS_JSON, opts)
269 end
is_not_json(opts=OPTS) click to toggle source

Return whether the json object cannot be parsed as JSON. The opposite of is_json. See is_json for options.

json_op.is_not_json                 # json IS NOT JSON
json_op.is_not_json(type: :object)  # json IS NOT JSON OBJECT
json_op.is_not_json(unique: true)   # json IS NOT JSON WITH UNIQUE
    # File lib/sequel/extensions/pg_json_ops.rb
277 def is_not_json(opts=OPTS)
278   _is_json(IS_NOT_JSON, opts)
279 end
keys() click to toggle source

Returns a set of keys AS text in the json object.

json_op.keys # json_object_keys(json)
    # File lib/sequel/extensions/pg_json_ops.rb
284 def keys
285   function(:object_keys)
286 end
populate(arg) click to toggle source

Expands the given argument using the columns in the json.

json_op.populate(arg) # json_populate_record(arg, json)
    # File lib/sequel/extensions/pg_json_ops.rb
291 def populate(arg)
292   SQL::Function.new(function_name(:populate_record), arg, self)
293 end
populate_set(arg) click to toggle source

Expands the given argument using the columns in the json.

json_op.populate_set(arg) # json_populate_recordset(arg, json)
    # File lib/sequel/extensions/pg_json_ops.rb
298 def populate_set(arg)
299   SQL::Function.new(function_name(:populate_recordset), arg, self)
300 end
strip_nulls() click to toggle source

Returns a json value stripped of all internal null values.

json_op.strip_nulls # json_strip_nulls(json)
    # File lib/sequel/extensions/pg_json_ops.rb
305 def strip_nulls
306   self.class.new(function(:strip_nulls))
307 end
to_record() click to toggle source

Builds arbitrary record from json object. You need to define the structure of the record using as on the resulting object:

json_op.to_record.as(:x, [Sequel.lit('a integer'), Sequel.lit('b text')]) # json_to_record(json) AS x(a integer, b text)
    # File lib/sequel/extensions/pg_json_ops.rb
313 def to_record
314   function(:to_record)
315 end
to_recordset() click to toggle source

Builds arbitrary set of records from json array of objects. You need to define the structure of the records using as on the resulting object:

json_op.to_recordset.as(:x, [Sequel.lit('a integer'), Sequel.lit('b text')]) # json_to_recordset(json) AS x(a integer, b text)
    # File lib/sequel/extensions/pg_json_ops.rb
321 def to_recordset
322   function(:to_recordset)
323 end
typeof() click to toggle source

Returns the type of the outermost json value as text.

json_op.typeof # json_typeof(json)
    # File lib/sequel/extensions/pg_json_ops.rb
328 def typeof
329   function(:typeof)
330 end

Private Instance Methods

_is_json(lit_array, opts) click to toggle source

Internals of IS [NOT] JSON support

    # File lib/sequel/extensions/pg_json_ops.rb
335 def _is_json(lit_array, opts)
336   raise Error, "invalid is_json :type option: #{opts[:type].inspect}" unless type = IS_JSON_MAP[opts[:type]]
337   unique = opts[:unique] ? WITH_UNIQUE : EMPTY_STRING
338   Sequel::SQL::BooleanExpression.new(:NOOP, Sequel::SQL::PlaceholderLiteralString.new(lit_array, [self, type, unique]))
339 end
function(name, *args) click to toggle source

Return a function with the given name, and the receiver as the first argument, with any additional arguments given.

    # File lib/sequel/extensions/pg_json_ops.rb
349 def function(name, *args)
350   SQL::Function.new(function_name(name), self, *args)
351 end
is_array?(a) click to toggle source

Whether the given object represents an array in PostgreSQL.

    # File lib/sequel/extensions/pg_json_ops.rb
354 def is_array?(a)
355   a.is_a?(Array) || (defined?(PGArray) && a.is_a?(PGArray)) || (defined?(ArrayOp) && a.is_a?(ArrayOp))
356 end
json_op(str, args) click to toggle source

Return a placeholder literal with the given str and args, wrapped in an JSONOp or JSONBOp, used by operators that return json or jsonb.

    # File lib/sequel/extensions/pg_json_ops.rb
343 def json_op(str, args)
344   self.class.new(Sequel::SQL::PlaceholderLiteralString.new(str, [self, args]))
345 end
wrap_array(arg) click to toggle source

Automatically wrap argument in a PGArray if it is a plain Array. Requires that the pg_array extension has been loaded to work.

    # File lib/sequel/extensions/pg_json_ops.rb
360 def wrap_array(arg)
361   if arg.instance_of?(Array) && Sequel.respond_to?(:pg_array)
362     Sequel.pg_array(arg)
363   else
364     arg
365   end
366 end