class Sequel::Postgres::JSONExistsOp

Object representing json_exists calls

Constants

ON_ERROR_SQL

Attributes

expr [R]

Expression (context_item in PostgreSQL terms), usually JSONBaseOp instance

on_error [R]

How to handle errors when evaluating the JSON path expression

passing [R]

Variables to set in the JSON path expression

path [R]

JSON path expression to apply against the expression

Public Class Methods

new (expr, path, opts=OPTS)

Source

    # File lib/sequel/extensions/pg_json_ops.rb
929 def initialize(expr, path, opts=OPTS)
930   @expr = expr
931   @path = path
932   @passing = opts[:passing]
933   @on_error = opts[:on_error]
934   freeze
935 end

See JSONBaseOp#exists for documentation on the options.

Public Instance Methods

sequel_ast_transform (transformer)

Source

    # File lib/sequel/extensions/pg_json_ops.rb
946 def sequel_ast_transform(transformer)
947   opts = {}
948   transform_opts(transformer, opts)
949   self.class.new(transformer.call(@expr), @path, opts)
950 end

Support transforming of function call expression

to_s_append (ds, sql)

Source

    # File lib/sequel/extensions/pg_json_ops.rb
938 def to_s_append(ds, sql)
939   to_s_append_function_name(ds, sql)
940   to_s_append_args_passing(ds, sql)
941   to_s_append_on_error(ds, sql)
942   sql << ')'
943 end

Append the SQL function call expression to the SQL

Private Instance Methods

to_s_append_args_passing (ds, sql)

Source

    # File lib/sequel/extensions/pg_json_ops.rb
972 def to_s_append_args_passing(ds, sql)
973   ds.literal_append(sql, @expr)
974   sql << ', '
975   ds.literal_append(sql, @path)
976 
977   if (passing = @passing) && !passing.empty?
978     sql << ' PASSING '
979     comma = false
980     passing.each do |k, v|
981       if comma
982         sql << ', '
983       else
984         comma = true
985       end
986       ds.literal_append(sql, v)
987       sql << " AS " << k.to_s
988     end
989   end
990 end

Append the expression, path, and optional PASSING fragments

to_s_append_function_name (ds, sql)

Source

    # File lib/sequel/extensions/pg_json_ops.rb
967 def to_s_append_function_name(ds, sql)
968   sql << 'json_exists('
969 end

to_s_append_on_error (ds, sql)

Source

    # File lib/sequel/extensions/pg_json_ops.rb
993 def to_s_append_on_error(ds, sql)
994   unless @on_error.nil?
995     sql << " "
996     to_s_append_on_value(ds, sql, @on_error)
997     sql << " ON ERROR"
998   end
999 end

Append the optional ON ERROR fragments

to_s_append_on_value (ds, sql, value)

Source

     # File lib/sequel/extensions/pg_json_ops.rb
1002 def to_s_append_on_value(ds, sql, value)
1003   sql << ON_ERROR_SQL.fetch(value)
1004 end

Append the value to use for ON ERROR

transform_opts (transformer, opts)

Source

    # File lib/sequel/extensions/pg_json_ops.rb
956 def transform_opts(transformer, opts)
957   if @passing
958     passing = opts[:passing] = {}
959     @passing.each do |k, v|
960       passing[k] = transformer.call(v)
961     end
962   end
963 
964   opts[:on_error] = @on_error
965 end

Set the :passing and :on_error options when doing an AST transform.