Joins are used to combine elements from different collections (e.g.
ImageCollection or FeatureCollection) based on a condition
specified by an ee.Filter. The filter is constructed with arguments for
the properties in each collection that are related to each other. Specifically,
leftField specifies the property in the primary collection that is related
to the rightField in the secondary collection. The type of filter (e.g.
equals, greaterThanOrEquals, lessThan, etc.)
indicates the relationship between the fields. The type of join indicates one-to-many
or one-to-one relationships between the elements in the collections and how many matches
to retain. The output of a join is produced by join.apply() and will vary
according to the type of join.
Join Overview
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Last updated 2021-05-26 UTC.
[null,null,["Last updated 2021-05-26 UTC."],[[["\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."]]