二级教程上翻遍了竟然没有！

Specifies a condition that records in the current table must meet to be accessible.

不会在VFP中help一下?

我装的VFP6.0没有HELP文件

呵呵!那你就装个全的呗!
我这儿的是英文版，所以给你的是英文的帮助!自己凑合着看吧!

Specifies a condition that records in the current table must meet to be accessible.
Syntax

SET FILTER TO [lExpression]

Arguments

lExpression Specifies the condition that records must satisfy.

If the current table is indexed on a field or fields specified in lExpression, Visual FoxPro Rushmore technology will optimize queries based on the field or fields.

Remarks

Once SET FILTER is issued, only the records that satisfy the condition specified by the logical expression lExpression are available in the table. All commands that access the table respect the SET FILTER condition. A separate filter can be set for every open table.

The condition specified by SET FILTER isn抰 evaluated until the record pointer is moved in the table.

Issuing SET FILTER TO without lExpression turns off the filter for the current table.

SELECT - SQL does not respect the current filter condition.

通俗地说,使用了SET FILTER TO lExpression,在许多含有for短语的命令中,就可省略FOR短语了!

英文不太好啊 哪里有中文的帮助文档

SET FILTER TO [lExpression]

参数
lExpression

指定记录必须满足的条件。
如果当前表在 lExpression 中指定的一个或多个字段上建立了索引，Visual FoxPro Rushmore 技术会优化基于这个或这些字段的查询。

说明

如果使用 set filter 命令，则表中只有满足逻辑表达式 lExpression 指定的条件的记录才可以被访问。所有访问该表的命令都必须遵守 SET FILTER 指定的条件。对于每个打开的表，都可以设置单独的筛选条件。
只有当记录指针在表中移动时，才计算由 SET FILTER 指定的条件。
不带 lExpression 发出 SET FILTER TO 命令将关闭当前表的选择器。
注意：SELECT - SQL 不遵守当前的筛选条件。