例如，要把字段值限定为所有数字，需要编写一个确保输入全都是数字的例程。

For instance, to limit values in a field to all Numbers, write a routine that makes sure the input is all Numbers.

youdao

字段的大小并不需要提前指定，不过您必须要知道字段大小的限定值。

Field sizes do not have to be specified up front, although you have to know the limitations of field sizes.

youdao

接下来，指定在提交已修改数据时需要包含到严格限定的update语句中的字段。

Next, specify the field (s) to include in the overqualified update statement when modified data is committed.

youdao