DELIMITER $$

CREATE OR REPLACE PROCEDURE usp_parsejson (
  IN _uuid VARCHAR(100),
  IN _json TEXT
)
/*
  CALL usp_parsejson('1234', '{ "id":"abc", "nmae": "Michael"}');
  SELECT * from _jsondata WHERE guid = '1234';
  
  DELETE FROM _jsondata WHERE guid = '1234';
*/
BEGIN
  DECLARE _json_clean TEXT;
  DECLARE _pair TEXT;
  DECLARE _key VARCHAR(255);
  DECLARE _value TEXT;
  DECLARE _valuetype VARCHAR(20);
  DECLARE _pos INT DEFAULT 1;
  DECLARE _len INT;
  DECLARE _curr INT DEFAULT 1;
  DECLARE _next INT;
  DECLARE _cnt INT DEFAULT 1;
  
  -- 建立暫存表
  CREATE TEMPORARY TABLE IF NOT EXISTS _jsondata (
    guid VARCHAR(100),
    rowid INT,
    fieldname VARCHAR(255),
    contents TEXT,
    fieldtype VARCHAR(20)
  );

  -- 清除左右大括號與空白
  SET _json_clean = REPLACE(_json,'{','');
  SET _json_clean = REPLACE(_json_clean,'}','');

  -- 計算逗號數（也就是 key:value 數）
  SET _len = LENGTH(_json_clean) - LENGTH(REPLACE(_json_clean, ',', '')) + 1;

  WHILE _cnt <= _len DO
    -- 取出第 cnt 個 key:value 配對
    SET _pair = SUBSTRING_INDEX(SUBSTRING_INDEX(_json_clean, ',', _cnt), ',', -1);

    -- 取出 key
    SET _key = SUBSTRING_INDEX(_pair, ':', 1);
    SET _key = REPLACE(TRIM(_key),'"','');
	
    -- 取出 value
    SET _value = SUBSTRING_INDEX(_pair, ':', -1);
    SET _value = TRIM(_value);

    -- 判斷型別
    IF LEFT(_value, 1) = '"' AND RIGHT(_value, 1) = '"' THEN
      SET _valuetype = 'string';
      SET _value = REPLACE(_value,'"','');
    ELSE
      SET _valuetype = 'number';
    END IF;

    -- 寫入結果
    INSERT INTO _jsondata (guid, rowid, fieldname, contents, fieldtype)
    VALUES (_uuid, _cnt, _key, _value, _valuetype);

    -- 下一筆
    SET _cnt = _cnt + 1;
  END WHILE;
END$$

DELIMITER ;