variable-length field

例句：

1. 1. In this program, we usea variable-length field to store theuser's name and email address.
   在这个程序中，我们使用可变长度字段来存储用户的姓名和电子邮件地址。
2. 2. Thevariable-length field in the database allowsus to easily update the data without havingto rewrite the entire record.
   数据库中的可变长度字段使我们能够轻松更新数据，而无需重新编写整个记录。
3. 3. Thevariable-length field is used to storelarge amounts of data that would otherwise betoo large to fit into a regular string.
   可变长度字段用于存储大量数据，否则这些数据将无法适应常规字符串的大小。