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ReQL command: literal

Command syntax

r.literal(object) → special

Description

Replace an object in a field instead of merging it with an existing object in a merge or update operation. Using literal with no arguments in a merge or update operation will remove the corresponding field.

Assume your users table has this structure:

[
    {
        "id": 1,
        "name": "Alice",
        "data": {
            "age": 18,
            "city": "Dallas"
        }
    }       
    ...
]

Using update to modify the data field will normally merge the nested documents:

r.table("users").get(1)
 .update(r.hashMap("data", r.hashMap("age", 19).with("job", "Engineer")))
 .run(conn);

// Result:
{
    "id": 1,
    "name": "Alice",
    "data": {
        "age": 19,
        "city": "Dallas",
        "job": "Engineer"
    }
}       

That will preserve city and other existing fields. But to replace the entire data document with a new object, use literal.

Example: Replace one nested document with another rather than merging the fields.

r.table("users").get(1)
 .update(r.hashMap("data", r.literal(r.hashMap("age", 19).with("job", "Engineer"))))
 .run(conn);

// Result:
{
    "id": 1,
    "name": "Alice",
    "data": {
        "age": 19,
        "job": "Engineer"
    }
}       

Example: Use literal to remove a field from a document.

r.table("users").get(1).merge(r.hashMap("data", r.literal())).run(conn);

// Result:
{
    "id": 1,
    "name": "Alice"
}

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https://rethinkdb.com/api/java/literal/