# Array Operations API (generated)

> Push, add to set, pull, pull all, pop and set elements of array fields in MongoDB documents with the generated array operations API of API Maker, several operations in one call.

Source: https://docs.apimaker.dev/v1/docs/apis-all/generated-apis/auto-generated-array-operations-api.html

Changes array fields of MongoDB documents in place : push, addToSet, pull, pullAll, pop and set, on every document matching `find`, several operations in one call.

| | |
|---|---|
| Method | PUT |
| URL | `/api/gen/admin/mysql8/inventory/customers/array-operations` |
| Body | `{ find, select?, operations: [ … ] }` |
| Query params | none |
| Answer | `data` : one array per operation with the documents matched, projected to the array (or `select`) |
| Databases | MongoDB only |
| Cached | no (a write ; it resets the cache of the table) |
| From code | [`g.sys.db.gen.arrayOperationsGen`](https://docs.apimaker.dev/v1/examples/sys/db/gen/arrayOperationsGen.html) |
| API id | `GEN_ARRAY_OPERATIONS` (groups, settings, hooks, WebSocket subscriptions) |
| The other family | [Array operations as a schema API](https://docs.apimaker.dev/v1/docs/apis-all/schema-apis/auto-generated-schema-based-array-operations-api.html) |

> **Schemaless : the data passes as it is**
>
> The generated APIs never read the [schema](https://docs.apimaker.dev/v1/docs/schema/schema.html) of the table. Nothing is converted, validated, defaulted, encrypted or numbered : what you send is what the database gets, and a filter matches the type you send (`"22"` does not match the number `22`). On MongoDB, strings which look like ObjectIds are converted. Every table has these APIs, with or without a schema ; the same operations under `/api/schema` apply the schema.

## The URL

`/api/gen/admin/mysql8/inventory/customers/array-operations` : replace `admin` with the user path of your account, `mongodb` with your instance, `inventory` with the database and `customers` with the table. The examples use this table :

| customer_id | first_name | last_name | last_update           | pincode | isActive |
|-------------|------------|-----------|-----------------------|---------|----------|
| 1           | Bob        | lin       | 2022-11-14 04: 34: 58 | 382345  | 1        |
| 2           | Alice      | Page      | 2022-10-15 02: 10: 40 | 382346  | 1        |
| 3           | Mallory    | Brown     | 2022-09-13 03: 44: 05 | 382347  | 1        |
| 4           | Eve        | Mathly    | 2022-11-12 01: 59: 33 | 382348  | 1        |
| 5           | Eve        | Page      | 2022-11-12 01: 59: 33 | 382349  | 1        |

## The body

```json
{
    "find": { "customer_id": 1 },
    "operations": [
        { "operation": "push", "path": "ages", "dataToPush": [ { "age": 33, "birth_year": 1989 } ] }
    ]
}
```

| Key | Meaning |
|---|---|
| `find` | Which documents to change. `{}` : all of them. |
| `select` | The fields to return for the matched documents. Without it, the array of `path`. |
| `operations` | Run one after the other, each on every matched document. |

| Operation | Keys | Does |
|---|---|---|
| `push` | `path`, `dataToPush` (array), `position`, `slice`, `sort` | Appends the items. `position` inserts at an index, `slice` keeps the first N (or last N when negative), `sort` (`{ field: 1 or -1 }`) reorders. |
| `addToSet` | `path`, `dataToPush` (one value or an array) | Appends only the values which are not there yet. |
| `pull` | `path`, `queryToRemove` | Removes every item matching the query. |
| `pullAll` | `path`, `dataToPull` (array) | Removes every item equal to one of the values. |
| `pop` | `path`, `direction` | `1` removes the last item, `-1` the first. |
| `set` | `dataToSet`, `arrayFilters`, `upsert` | Updates fields of items with the positional `$[item]` syntax and its filters. |

## Push and pull

**Push two items at the front, keep the array at 10**

```json
{ "find": {}, "operations": [ { "operation": "push", "path": "ages", "dataToPush": [ { "age": 2 }, { "age": 5 } ], "position": 0, "slice": 10, "sort": { "age": 1 } } ] }
```

**Remove the items of a year**

```json
{ "find": { "customer_id": 1 }, "operations": [ { "operation": "pull", "path": "ages", "queryToRemove": { "birth_year": 1989 } } ] }
```

**Remove exact values**

```json
{ "find": {}, "operations": [ { "operation": "pullAll", "path": "tags", "dataToPull": [ "old", "draft" ] } ] }
```

## Set inside an array

```json
{
    "find": {},
    "operations": [ {
        "operation": "set",
        "dataToSet": { "ages.$[item].age": 45, "ages.$[item].birth_year": 1999 },
        "arrayFilters": [ { "item.birth_year": 1999 } ],
        "upsert": true
    } ]
}
```

- `arrayFilters` decide which items `$[item]` means, `upsert: true` inserts a document when `find` matches none.

## Several operations at once

```json
{ "find": {}, "operations": [
    { "operation": "push", "path": "ages", "dataToPush": [ { "age": 60 } ] },
    { "operation": "pull", "path": "ages", "queryToRemove": { "age": 2 } }
] }
```

**Answer : one entry per operation**

```json
{ "success": true, "statusCode": 200, "data": [
    [ { "_id": "63e0775abd0e063920533f7c", "ages": [ { "age": 33 }, { "age": 60 } ] } ],
    [ { "_id": "63e0775abd0e063920533f7c", "ages": [ { "age": 33 }, { "age": 60 } ] } ]
] }
```

## From your code

[`g.sys.db.gen.arrayOperationsGen`](https://docs.apimaker.dev/v1/examples/sys/db/gen/arrayOperationsGen.html) makes the same call from custom APIs, hooks, events, schedulers and test cases, with the same headers and params. Pass `true` as the second argument to get the whole [response envelope](https://docs.apimaker.dev/v1/docs/apis-all/response-format.html) instead of `data`.

## Headers

Every call takes the [request headers](https://docs.apimaker.dev/v1/docs/apis-all/header/requestHeader.html) : the tokens, `x-am-response-case`, `x-am-content-type-response` (JSON, XML, YAML…), `x-am-response-object-type: make_flat`, `x-am-cache-control`, `x-am-get-encrypted-data`, `x-am-internationalization`, `x-am-tenant-username`, `x-am-meta`.

## Errors

| Code | When |
|---|---|
| `401` | The token in `x-am-authorization` is missing or invalid. |
| `403` | No group of the API user grants this API of this table, or a field of the request. |
| `404` | The instance, database or table of the URL does not exist. |
| `400` | The query or the body is wrong : the [error messages](https://docs.apimaker.dev/v1/docs/apis-all/error-codes.html) say which key and why. |

## Related

- [All APIs at a glance](https://docs.apimaker.dev/v1/docs/apis-all/overview.html) · [Query params](https://docs.apimaker.dev/v1/docs/apis-all/query-params/query-params.html) · [Response format](https://docs.apimaker.dev/v1/docs/apis-all/response-format.html) · [Pre hooks](https://docs.apimaker.dev/v1/docs/apis-all/hooks/preHook-api.html) and [post hooks](https://docs.apimaker.dev/v1/docs/apis-all/hooks/postHook-api.html) · [Automatic caching](https://docs.apimaker.dev/v1/docs/features/automatic-caching.html)