PHP unserialize in Postgresql to json

php_unserialize_to_json.sql

/**
Decode a php serialized value to json. This function only supports basic 
data types:
- arrays (will always become a json object)
- booleans
- integers
- floats
- strings
- NULL
The php_unserialize(text) function is a helper function which extracts the first value
found in the string and returns a ROW( vartype, varval, serializedlength)
The php_unserialize_to_json(text) function returns the json value extracted from
the serialized string. 
*/

---
--- This function is the helper function
---

CREATE OR REPLACE FUNCTION public.php_unserialize(str text)
  RETURNS json AS
$BODY$
DECLARE
  vartype CHAR;
  varlength INT;
  jsonstr TEXT;
  varcount INT;
  jsonval JSONB;
  arrkey JSON;
  arrval JSON;
  -- String length of the serialized data
  serialized_string_length INT;
BEGIN
  CASE substring(str, 1, 1)
    WHEN 'a' THEN -- array
      -- init object
      jsonval := '{}'::jsonb;
      
      -- remove the "a" and ":" characters
      str := substring(str, 3);
      
      -- Detect number of values in array
      varlength := substring(str, 1, position(':' IN str) - 1)::INT;
      
      -- Base size of array is 5 (a:[size]:{})
      serialized_string_length := 5 + char_length(varlength::TEXT);
      
      -- If no values, return empty object, as this always returns objects
      IF varlength = 0 THEN 
        return json_build_array('array', '{}'::JSON, serialized_string_length)::JSON;
      END IF;

      -- remove the array size and ":{"
      str := substring(str, char_length(varlength::TEXT) + 3);
      
      -- Find the number of variables specified
      FOR varcount IN 1 .. varlength LOOP
        -- Find the value of the key and remove it from base string
        arrkey := php_unserialize(str);
        str := substring(str, (arrkey->>2)::INT + 1);

        -- Find the value of the value and remove it from base string
        arrval := php_unserialize(str);
        str := substring(str, (arrval->>2)::INT + 1);

        serialized_string_length := serialized_string_length + (arrkey->>2)::INT + (arrval->>2)::INT;

        -- Append value
        jsonval := jsonval || jsonb_build_object(arrkey->>1, arrval->1);
      END LOOP;
      
      return json_build_array('array', jsonval, serialized_string_length);
    WHEN 'b' THEN -- boolean
      return json_build_array('bool',(CASE substring(str, 3, 1) WHEN '1' THEN TRUE ELSE FALSE END)::BOOL, 4);
    WHEN 'd' THEN -- float
      return json_build_array('float', substring(str, 3, position(';' IN str) - 3)::DOUBLE PRECISION, position(';' IN str));
    WHEN 'i' THEN -- int
      return json_build_array('int', substring(str, 3, position(';' IN str) - 3)::INT, position(';' IN str));
    WHEN 'N' THEN -- null
      return json_build_array('null', NULL, 2);
    WHEN 's' THEN -- string
      varlength := regexp_replace(substring(str, 3, position(':' IN str)), '[^0-9]+', '', 'g')::INT;
      
      return json_build_array('string', substring(str, char_length(varlength::TEXT) + 5, varlength)::TEXT, position(';' IN str));
    ELSE
      RAISE EXCEPTION 'Unable to decode serialized value, unsupported type: %', substr(str, 1, 1);
  END CASE;
END;
$BODY$
  LANGUAGE plpgsql IMMUTABLE
  COST 10;
  
---
--- The main function
---
CREATE OR REPLACE FUNCTION public.php_unserialize_to_json(str text)
  RETURNS json AS
$BODY$
DECLARE
  varlength INT;
BEGIN
  CASE substring(str, 1, 1)
    WHEN 'a' THEN
      return php_unserialize(str)->1;
    WHEN 'b' THEN
      return php_unserialize(str)->1;
    WHEN 'd' THEN
      return php_unserialize(str)->1;
    WHEN 'i' THEN
      return php_unserialize(str)->1;
    WHEN 'N' THEN
      return php_unserialize(str)->1;
    WHEN 's' THEN
      return php_unserialize(str)->1;
    ELSE
      RETURN NULL;
  END CASE;
END;
$BODY$
  LANGUAGE plpgsql IMMUTABLE
  COST 10;
  


CREATE OR REPLACE FUNCTION public.test_php_unserialize_to_json()
  RETURNS void AS
$BODY$
DECLARE
BEGIN
  
  IF 
  	php_unserialize_to_json('N;')::TEXT
	<> 'null'
  THEN
    RAISE EXCEPTION 'Expected null, got "%"', php_unserialize_to_json('N;')::TEXT;
  END IF;
  
  IF 
  	php_unserialize_to_json('b:1;')::TEXT
	<> 'true'
  THEN
    RAISE EXCEPTION 'Expected true, got "%"', php_unserialize_to_json('b:1;')::TEXT;
  END IF;
  
  IF 
  	php_unserialize_to_json('b:0;')::TEXT
	<> 'false'
  THEN
    RAISE EXCEPTION 'Expected false, got "%"', php_unserialize_to_json('b:0;')::TEXT;
  END IF;
  
  IF 
  	php_unserialize_to_json('i:1337;')::TEXT
	<> '1337'
  THEN
    RAISE EXCEPTION 'An integer 1337, got "%"', php_unserialize_to_json('i:1337;')::TEXT;
  END IF;
  
  IF 
  	php_unserialize_to_json('d:1.337;')::TEXT
	<> '1.337'
  THEN
    RAISE EXCEPTION 'An double 1.337, got "%"', php_unserialize_to_json('d:1.337;')::TEXT;
  END IF;
  
  IF 
  	php_unserialize_to_json('s:0:"";')::TEXT
	<> '""'
  THEN
    RAISE EXCEPTION 'An empty string, got "%"', php_unserialize_to_json('s:0:"";')::TEXT;
  END IF;
  
  IF 
  	php_unserialize_to_json('s:8:"a string";')::TEXT
	<> '"a string"'
  THEN
    RAISE EXCEPTION 'Expected value "a string", got "%"', php_unserialize_to_json('s:8:"a string";')::TEXT;
  END IF;
  
  IF 
  	(php_unserialize_to_json('s:15:"a longer string";'))::TEXT
	<> '"a longer string"'
  THEN
    RAISE EXCEPTION 'Expected value "a longer string", got "%"', php_unserialize_to_json('s:15:"a longer string";')::TEXT;
  END IF;
  
  IF 
  	(php_unserialize_to_json('a:0:{}'))::TEXT
	<> '{}'
  THEN
    RAISE EXCEPTION 'Expected empty array, got "%"', php_unserialize_to_json('a:0:{}')::TEXT;
  END IF;
  
  IF 
  	(php_unserialize_to_json('a:1:{i:0;s:5:"array";}'))::TEXT
	<> ('{"0": "array"}'::JSON)::TEXT
  THEN
    RAISE EXCEPTION 'Expected array with one value, got "%"', php_unserialize_to_json('a:1:{i:0;s:5:"array";}')::TEXT;
  END IF;
  
  IF 
  	(php_unserialize_to_json('a:2:{i:0;i:123;i:1;b:1;}'))::TEXT
	<> ('{"0": 123, "1": true}'::JSON)::TEXT
  THEN
    RAISE EXCEPTION 'Expected array with one value, got "%"', php_unserialize_to_json('a:2:{i:0;i:123;i:1;b:1;}')::TEXT;
  END IF;
  
  IF 
  	(php_unserialize_to_json('a:1:{i:0;i:123;}'))::TEXT
	<> ('{"0": 123}'::JSON)::TEXT
  THEN
    RAISE EXCEPTION 'Expected array with one value, got "%"', php_unserialize_to_json('a:1:{i:0;i:123;}')::TEXT;
  END IF;
  
  IF 
  	php_unserialize_to_json('a:5:{i:0;d:1;s:1:"k";a:3:{i:0;s:1:"a";i:1;s:1:"b";s:3:"sub";a:3:{i:0;s:1:"a";i:1;s:1:"b";i:2;s:1:"c";}}i:1;N;i:2;b:1;i:3;b:0;}')::TEXT
	<> ('{"0": 1, "1": null, "2": true, "3": false, "k": {"0": "a", "1": "b", "sub": {"0": "a", "1": "b", "2": "c"}}}'::JSON)::TEXT
  THEN
    RAISE EXCEPTION 'Unexpected complex value, got: "%"', php_unserialize_to_json('a:5:{i:0;d:1;s:1:"k";a:3:{i:0;s:1:"a";i:1;s:1:"b";s:3:"sub";a:3:{i:0;s:1:"a";i:1;s:1:"b";i:2;s:1:"c";}}i:1;N;i:2;b:1;i:3;b:0;}')::TEXT;
  END IF;
-- SELECT php_unserialize_to_json('a:2:{i:0;d:1;s:1:"k";a:2:{i:0;s:1:"a";i:1;s:1:"b";}}')::TEXT;
END;
$BODY$
  LANGUAGE plpgsql IMMUTABLE
  COST 10;

SELECT public.test_php_unserialize_to_json();
DROP FUNCTION public.test_php_unserialize_to_json();

Hi
It fails to unserialize a simple array:

SELECT php_unserialize_to_json('a:1:{s:3:"abc";s:10:"abcde12345";}')::TEXT

Output is:

{"abc": "\""}

Looks like arrays with string keys are getting messed up.

Thanks,
gali

Hi @storeman ,

thanks for this solution! but I noticed that this works only with arrays with items length < 10. For example (using @galiganu example) :

SELECT php_unserialize_to_json('a:1:{s:3:"abc";s:10:"abcde12345"}');
 php_unserialize_to_json 
-------------------------
 {"abc": "\""}
(1 row)

This is not working as expected, but if I change "10" to "9" it works better:

SELECT php_unserialize_to_json('a:1:{s:3:"abc";s:9:"abcde12345"}');
 php_unserialize_to_json 
-------------------------
 {"abc": "abcde1234"}
(1 row)

So I replaced this:

WHEN 's' THEN -- string
      varlength := substring(str, 3, position(':' IN str) - 1)::INT;

with this (removed the "-1" and added a 'regexp_replace' to get only numbers):

WHEN 's' THEN -- string
      varlength := regexp_replace(substring(str, 3, position(':' IN str)), '[^0-9]+', '', 'g')::INT;

and now works as expected:

SELECT php_unserialize_to_json('a:1:{s:3:"abc";s:10:"abcde12345";}')::TEXT
;
 php_unserialize_to_json 
-------------------------
 {"abc": "abcde12345"}
(1 row)

Thanks @roldan, @galiganu for letting me know. There were also some issues with the types of integers, floats, bools and nulls. These are now correctly returned in the json. I also added a test-function which runs and deletes after valid testing.

Line #50
return json_build_array('array', '{}'::TEXT[], serialized_string_length)::JSON;
will return [] in the end (at least for me on postgres13), and that will break functions expecting an object and not an array

@synchrone I understand, a consistent return type is better. I changed it and updated the test.

Awesome function! This is a life saver migrating wordpress data into pg. I ran into a case where it fails for strings larger than 99 chars. I changed the function to this for strings position(':"' IN str)-1 the :" is a better stop I think. These were strings that had "https://" in them as well.

    WHEN 's' THEN -- string
      varlength := regexp_replace(substring(str, 3, position(':"' IN str)-1), '[^0-9]+', '', 'g')::INT;

Hi guys i am trying to parse a json that has html content and i get the following error:
select php_unserialize_to_json('a:4:{s:7:"content";s:331:"<p dir="ltr" style="text-align:left;">Buenas noches, mi nombre es Ovando Yésica. Estoy en mi primer año de la carrera de LGTI. Me interese por esta carrera por que hice un curso en operación de computadoras y me despertó la curiosidad de aprender más sobre la industria de la tecnología. Les deseo buena cursada a todos!!</p>";s:14:"pathnamehashes";a:0:{}s:12:"discussionid";i:327611;s:13:"triggeredfrom";s:20:"forum_add_discussion";}')

ERROR: Unable to decode serialized value, unsupported type: "
CONTEXT: función PL/pgSQL php_unserialize(text) en la línea 66 en RAISE
función PL/pgSQL php_unserialize(text) en la línea 38 en asignación
función PL/pgSQL php_unserialize_to_json(text) en la línea 7 en RETURN
SQL state: P0001

Can you help me? Thanks

Yes, you need to escape this char " in your HTML : <p dir="ltr"

select substring((regexp_matches(db_fieldname,'("\d+")','g'))[1] from '"(\d+)"') from db_tablename

I modded your gist for support Objects (stdClass) and strings separated by ";" ("text1;text2;text3;text4")

      `CREATE OR REPLACE FUNCTION public.php_unserialize(str text)
        RETURNS json AS
      $BODY$
      DECLARE
        vartype CHAR;
        varlength INT;
        jsonstr TEXT;
        varcount INT;
        jsonval JSONB;
        arrkey JSON;
        arrval JSON;
        -- String length of the serialized data
        serialized_string_length INT;
      BEGIN
        CASE substring(str, 1, 1)
          WHEN 'a' THEN -- array
            -- init object
            jsonval := '{}'::jsonb;
            
            -- remove the "a" and ":" characters
            str := substring(str, 3);
            
            -- Detect number of values in array
            varlength := substring(str, 1, position(':' IN str) - 1)::INT;
            
            -- Base size of array is 5 (a:[size]:{})
            serialized_string_length := 5 + char_length(varlength::TEXT);
            
            -- If no values, return empty object, as this always returns objects
            IF varlength = 0 THEN 
              return json_build_array('array', '{}'::JSON, serialized_string_length)::JSON;
            END IF;
      
            -- remove the array size and ":{"
            str := substring(str, char_length(varlength::TEXT) + 3);
            
            -- Find the number of variables specified
            FOR varcount IN 1 .. varlength LOOP
              -- Find the value of the key and remove it from base string
              arrkey := php_unserialize(str);
              str := substring(str, (arrkey->>2)::INT + 1);
      
              -- Find the value of the value and remove it from base string
              arrval := php_unserialize(str);
              str := substring(str, (arrval->>2)::INT + 1);
      
              serialized_string_length := serialized_string_length + (arrkey->>2)::INT + (arrval->>2)::INT;
      
              -- Append value
              jsonval := jsonval || jsonb_build_object(arrkey->>1, arrval->1);
            END LOOP;
            
            return json_build_array('array', jsonval, serialized_string_length);
          WHEN 'O' THEN -- Object
            -- init object
            jsonval := '{}'::jsonb;
            
            -- remove the "a" and ":" characters
            str := substring(str, 16);
            
            -- Detect number of values in array
            varlength := substring(str, 1, position(':' IN str) - 1)::INT;
            
            -- Base size of array is 5 (a:[size]:{})
            serialized_string_length := 5 + char_length(varlength::TEXT);
            
            -- If no values, return empty object, as this always returns objects
            IF varlength = 0 THEN 
              return json_build_array('array', '{}'::JSON, serialized_string_length)::JSON;
            END IF;
      
            -- remove the array size and ":{"
            str := substring(str, char_length(varlength::TEXT) + 3);
            
            -- Find the number of variables specified
            FOR varcount IN 1 .. varlength LOOP
              -- Find the value of the key and remove it from base string
              arrkey := php_unserialize(str);
              str := substring(str, (arrkey->>2)::INT + 1);
      
              -- Find the value of the value and remove it from base string
              arrval := php_unserialize(str);
              str := substring(str, (arrval->>2)::INT + 1);
      
              serialized_string_length := serialized_string_length + (arrkey->>2)::INT + (arrval->>2)::INT;
      
              -- Append value
              jsonval := jsonval || jsonb_build_object(arrkey->>1, arrval->1);
            END LOOP;
            
            return json_build_array('array', jsonval, serialized_string_length);
          WHEN 'b' THEN -- boolean
            return json_build_array('bool',(CASE substring(str, 3, 1) WHEN '1' THEN TRUE ELSE FALSE END)::BOOL, 4);
          WHEN 'd' THEN -- float
            return json_build_array('float', substring(str, 3, position(';' IN str) - 3)::DOUBLE PRECISION, position(';' IN str));
          WHEN 'i' THEN -- int
            return json_build_array('int', substring(str, 3, position(';' IN str) - 3)::INT, position(';' IN str));
          WHEN 'N' THEN -- null
            return json_build_array('null', NULL, 2);
          WHEN 's' THEN -- string
            varlength := substring(str, 3, position(':' IN substring(str, 3)) - 1)::INT;
            return json_build_array('string', substring(str, char_length(varlength::TEXT) + 5, varlength)::TEXT, position('";' IN str) + 1);
          ELSE
            RAISE EXCEPTION 'Unable to decode serialized value, unsupported type: %', substr(str, 1, 1);
        END CASE;
      END;
      $BODY$
        LANGUAGE plpgsql IMMUTABLE
        COST 10;
        
      ---
      --- The main function
      ---
      CREATE OR REPLACE FUNCTION public.php_unserialize_to_json(str text)
        RETURNS json AS
      $BODY$
      DECLARE
        varlength INT;
      BEGIN
        CASE substring(str, 1, 1)
          WHEN 'a' THEN
            return php_unserialize(str)->1;
          WHEN 'O' THEN
            return php_unserialize(str)->1;
          WHEN 'b' THEN
            return php_unserialize(str)->1;
          WHEN 'd' THEN
            return php_unserialize(str)->1;
          WHEN 'i' THEN
            return php_unserialize(str)->1;
          WHEN 'N' THEN
            return php_unserialize(str)->1;
          WHEN 's' THEN
            return php_unserialize(str)->1;
          ELSE
            RETURN NULL;
        END CASE;
      END;
      $BODY$
        LANGUAGE plpgsql IMMUTABLE
        COST 10;`