code: function(collectionName, criterion, key, parentKey) {
          var queryPart = '';
  
  
          if (parentKey) {
              return sql.prepareCriterion(collectionName, criterion, key, parentKey);
          }
  
          // OR
          if (key.toLowerCase() === 'or') {
              queryPart = sql.build(collectionName, criterion, sql.where, ' OR ');
              return ' ( ' + queryPart + ' ) ';
          }
  
          // AND
          else if (key.toLowerCase() === 'and') {
              queryPart = sql.build(collectionName, criterion, sql.where, ' AND ');
              return ' ( ' + queryPart + ' ) ';
          }
  
          // IN
          else if (_.isArray(criterion)) {
              queryPart = sql.prepareAttribute(collectionName, null, key) + " IN (" + sql.values(collectionName, criterion, key) + ")";
              return queryPart;
          }
  
          // LIKE
          else if (key.toLowerCase() === 'like') {
              return sql.build(collectionName, criterion, function(collectionName, value, attrName) {
                  var attrStr = sql.prepareAttribute(collectionName, value, attrName);
  
                  attrStr = attrStr.replace(/'/g, '"');
  
                  // TODO: Handle regexp criterias
                  if (_.isRegExp(value)) {
                      throw new Error('RegExp LIKE criterias not supported by the MySQLAdapter yet.  Please contribute @ http://github.com/balderdashy/sails-mysql');
                  }
  
                  var valueStr = sql.prepareValue(collectionName, value, attrName);
  
                  // Handle escaped percent (%) signs [encoded as %%%]
                  valueStr = valueStr.replace(/%%%/g, '\\%');
                  var condition = (attrStr + " LIKE " + valueStr);
  
                  //condition = condition.replace(/'/g, '"');
  
                  return condition;
              }, ' AND ');
          }
  
          // NOT
          else if (key.toLowerCase() === 'not') {
              throw new Error('NOT not supported yet!');
          }
  
          // Basic criteria item
          else {
              return sql.prepareCriterion(collectionName, criterion, key);
          }
  
      }
docs: Recursively parse a predicate calculus and build a SQL query