Function array_to_json 

pub fn array_to_json<Arr: ArrayOrNullableArray + MaybeNullableValue<Json>, array>(
    array: array,
) -> array_to_json<Arr, array>
where
    array: AsExpression<Arr>,

Available on crate feature postgres_backend only.

Converts any Array to json.

Example

let json = diesel::select(array_to_json::<Array<Integer>, _>(vec![1, 2, 3, 4, 5]))
    .get_result::<Value>(connection)?;
let expected: Value = serde_json::json!([1, 2, 3, 4, 5]);
assert_eq!(expected, json);
let json = diesel::select(array_to_json::<Array<Text>, _>(vec![
    "hello", "world", "John", "Doe",
]))
.get_result::<Value>(connection)?;
let expected: Value = serde_json::json!(["hello", "world", "John", "Doe"]);
assert_eq!(expected, json);
let empty: Vec<String> = Vec::new();
let json = diesel::select(array_to_json::<Array<Nullable<Text>>, _>(empty))
    .get_result::<Value>(connection)?;
assert_eq!(serde_json::json!([]), json);
let json = diesel::select(array_to_json::<Nullable<Array<Integer>>, _>(
    None::<Vec<i32>>,
))
.get_result::<Option<Value>>(connection)?;
assert_eq!(None, json);