# Master Save and Update API

> Master-level save/update for single or multiple records with full control—perfect for robust backend data management.

Source: https://docs.apimaker.dev/v1/examples/sys/db/gen/masterSaveGen.html

`g.sys.db.gen.masterSaveGen` calls the [master save generated API](https://docs.apimaker.dev/v1/docs/apis-all/generated-apis/auto-generated-master-save-api.html) from your code : no schema, the data as it is in the table.

## Structure

**Master save**

```typescript
let masterSave = await g.sys.db.gen.masterSaveGen({
    instance: "INSTANCE_NAME", database: 'DB_NAME', collection: "COLLECTION_NAME",
    saveData: {
        first_name: "James",
        last_name: "Bond"
    }
});
```

## master save single data

**Master save**

```typescript
let masterSave = await g.sys.db.gen.masterSaveGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    saveData: {
        "first_name": "Bob",
        "last_name": "Lin"
    }
});
```

## master save multiple data

**Master save**

```typescript
let masterSave = await g.sys.db.gen.masterSaveGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    saveData: [
        {
            "first_name": "Bob",
            "last_name": "Lin"
        },
        {
            "first_name": "Bob",
            "last_name": "Lin"
        }
    ]
});
```

## with header

**Master save with header**

```typescript
let masterSave = await g.sys.db.gen.masterSaveGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    saveData: {
        "first_name": "Bob",
        "last_name": "Lin"
    },
    headers: {
        "x-am-response-case": "capitalCase"
    }
});
```

## multiple database entry

**Master save with multy data[with help of schema configuration]**

```typescript
let masterSave = await g.sys.db.gen.masterSaveGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    saveData: {
        "city_name": "Wembley", //city_name save in mysql database
        "state_id": {
            "state_name": "London", //state_name save in maria database
            "country_id": {
                "country_name":"UK" //country_name save in postGreSql database
            }
        }
    },
    headers: {
        "x-am-response-case": "capitalCase"
    }
});
```

## multiple database multiple entry entry

**Master save with multy data[with help of schema configuration]**

```typescript
let masterSave = await g.sys.db.gen.masterSaveGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    saveData: [{
        "city_name": "Wembley",
        "state_id": {
            "state_name": "London",
            "country_id": 302
        }
    },
    {
        "city_name": "Buffalo",
        "state_id": {
            "state_name": "Chicago",
            "country_id": 303
        }
    }],
    headers: {
        "x-am-response-case": "capitalCase"
    }
});
```

## Multi-tenant
- `instance: "crm::acme"` works on the database of the tenant `acme` of the [multi-tenant](https://docs.apimaker.dev/v1/docs/features/multi-tenant.html) instance `crm`.
- With `instance: "crm"`, the call works on the database of the tenant of the request: a custom API called with the [x-am-tenant-username](https://docs.apimaker.dev/v1/docs/apis-all/header/requestHeader.html#x-am-tenant-username) header passes it on to the APIs it calls. A request without a tenant works on the structure database.

**Master save a customer of the tenant acme**

```typescript
let masterSave = await g.sys.db.gen.masterSaveGen({
    instance: "crm::acme", database: "crm", collection: "customers",
    saveData: {
        "first_name": "Bob",
        "last_name": "Lin"
    }
});
```

## Related

- [Master save generated API](https://docs.apimaker.dev/v1/docs/apis-all/generated-apis/auto-generated-master-save-api.html) · [Schema API from code](https://docs.apimaker.dev/v1/examples/sys/db/masterSave.html) · [The global object g](https://docs.apimaker.dev/v1/docs/pre-defined-terms/global-object-g.html)