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使用集合让一切井井有条
根据您的偏好保存内容并对其进行分类。
联接用于根据 ee.Filter 指定的条件组合来自不同集合（例如 ImageCollection 或 FeatureCollection）的元素。过滤条件是使用每个集合中彼此相关的属性的参数构建的。具体而言，leftField 指定主要集合中与次要集合中的 rightField 相关的属性。过滤器的类型（例如 equals、greaterThanOrEquals、lessThan 等）
表示字段之间的关系。联接类型表示集合中元素之间的一对多或一对一关系，以及要保留的匹配数量。联接的输出由 join.apply() 生成，并会因联接类型而异。
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最后更新时间 (UTC)：2025-07-25。
[null,null,["最后更新时间 (UTC)：2025-07-25。"],[[["\u003cp\u003eJoins combine elements from different collections like \u003ccode\u003eImageCollection\u003c/code\u003e and \u003ccode\u003eFeatureCollection\u003c/code\u003e based on a specified condition using an \u003ccode\u003eee.Filter\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eee.Filter\u003c/code\u003e defines the relationship between properties in the collections using \u003ccode\u003eleftField\u003c/code\u003e and \u003ccode\u003erightField\u003c/code\u003e along with a filter type like \u003ccode\u003eequals\u003c/code\u003e or \u003ccode\u003elessThan\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eDifferent join types handle one-to-one or one-to-many relationships and control the number of matches retained, impacting the output produced by \u003ccode\u003ejoin.apply()\u003c/code\u003e.\u003c/p\u003e\n"]]],["Joins combine elements from different collections using an `ee.Filter` based on a specified condition. `leftField` and `rightField` define related properties within the primary and secondary collections, respectively. The filter type determines the relationship between these fields (e.g., equals, greaterThan). Join type specifies one-to-many or one-to-one relationships and the number of matches. The `join.apply()` method produces the output, which varies based on the chosen join type.\n"],null,["# Join Overview\n\nJoins are used to combine elements from different collections (e.g.\n`ImageCollection` or `FeatureCollection`) based on a condition\nspecified by an `ee.Filter`. The filter is constructed with arguments for\nthe properties in each collection that are related to each other. Specifically,\n`leftField` specifies the property in the primary collection that is related\nto the `rightField` in the secondary collection. The type of filter (e.g.\n`equals`, `greaterThanOrEquals`, `lessThan`, etc.)\nindicates the relationship between the fields. The type of join indicates one-to-many\nor one-to-one relationships between the elements in the collections and how many matches\nto retain. The output of a join is produced by `join.apply()` and will vary\naccording to the type of join."]]
