to_json.sql

CREATE OR REPLACE FUNCTION escape_json (text) RETURNS text AS $$                                    
SELECT replace($1, '"', '"'); $$ LANGUAGE SQL IMMUTABLE;                                            
                                                                                                    
                                                                                                    
CREATE OR REPLACE FUNCTION to_json(text) RETURNS text AS $$                                         
SELECT escape_json($1) $$ LANGUAGE SQL IMMUTABLE;                                                   
                                                                                                    
                                                                                                    
CREATE OR REPLACE FUNCTION to_json(KEY text, value text) RETURNS text AS $$                         
SELECT '"' || to_json($1) || '" : "' || to_json($2) || '"'; $$ LANGUAGE SQL IMMUTABLE;              
                                                                                                    
                                                                                                    
CREATE OR REPLACE FUNCTION to_json(hstore) RETURNS text AS $$                                       
SELECT '{' || array_to_string(array_agg(to_json(item.KEY, item.value)), ', ') || '}'                
FROM each($1) item; $$ LANGUAGE SQL IMMUTABLE;                                                      
                                                                                                    
                                                                                                    
CREATE OR REPLACE FUNCTION to_json(text[]) RETURNS text AS $$                                       
SELECT to_json(hstore($1)); $$ LANGUAGE SQL IMMUTABLE;                                              
                                                                                                    
SELECT to_json(hstore(array[array['a', 'b'], array['c', 'd']])) two_dimensional_array_to_hstore_to_json,
       to_json(array[array['a', 'b'], array['c', 'd']]) two_dimensional_array_to_to_json,           
       to_json(hstore(array['a', 'b'], array['c', 'd'])) multi_array_to_hstore_to_json,             
       to_json(hstore(array['a', 'b', 'c', 'd'])) array_to_hstore_to_json,                          
       to_json(array['a', 'b', 'c', 'd']) array_to_to_json;