r.literal(object) → special
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({ :data => { :age => 19, :job => 'Engineer' } }).run(conn)
{
: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({ :data => r.literal({ :age => 19, :job => 'Engineer' }) }).run(conn)
{
: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({:data => r.literal() }).run(conn)
{
:id => 1,
:name => "Alice"
}
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