Sets
Before version 3.0.0-beta, sets were simply arrays that deduplicated their items. To emulate the former behaviour, add the clause VALUE $value.distinct() to a DEFINE FIELD definition.
A set is similar to an array, but with two key differences:
- The values in a set are automatically deduplicated.
- The values in a set are automatically ordered.
A set can be created using the literal syntax {}.
RETURN {1, 6, 6, 2};
To create a set with zero items or a single item, add a comma.
{,}.is_set();
{9,}.is_set();
{}.is_set();
{9}.is_set();
In addition to the {} literal syntax, an array can be cast into a set.
DEFINE FIELD bank_accounts ON TABLE customer TYPE array<int>;
DEFINE FIELD languages ON TABLE customer TYPE set<string>;
CREATE customer SET
bank_accounts = [
55555,
55555,
98787
],
languages = <set>[
"en",
"ja",
"kr",
"kr"
];
Output
[
{
bank_accounts: [
55555,
98787
],
id: customer:uv6mn62t8td9vzvfogh4,
languages: {
'en',
'ja',
'kr'
}
}
]
Casting into a set and back into an array can be a convenient way to deduplicate items in the same way that the array::distinct() and array::sort() functions are used.
<array><set>[18,7,6,6,6,6,5,4,3,9];
[18,7,6,6,6,6,5,4,3,9].distinct().sort();
Output
[3, 4, 5, 6, 7, 9, 18]
