framework/db/conditions/BetweenColumnsConditionBuilder.php
protected function createPlaceholder($value, &$params)
    {
        if ($value instanceof ExpressionInterface) {
            return $this->queryBuilder->buildExpression($value, $params);
        }

        return $this->queryBuilder->bindParam($value, $params);
    }
protected function createPlaceholder($value, &$params)
    {
        if ($value instanceof ExpressionInterface) {
            return $this->queryBuilder->buildExpression($value, $params);
        }

        return $this->queryBuilder->bindParam($value, $params);
    }
Attaches $value to $params array and returns placeholder.

@param mixed $value
@param array $params passed by reference
@return string