# Advanced Query for Get Data API

> Run complex filtered and paginated queries to retrieve precise datasets—perfect for dynamic app needs.

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

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

## Structure

**Query method**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "INSTANCE_NAME", database: 'DB_NAME', collection: "COLLECTION_NAME",
    find: {
        "pincode": 100050
    },
    limit: 1,
    select: "COLUMN_NAMES",
    deep: [{
        s_key: "SOURCE_COLLECTION_COLUMN_NAME",
        t_key: "TARGET_COLLECTION_COLUMN_NAME",
        t_col: "TARGET_COLLECTION_NAME",
        select: "COLUMN_NAMES"
    }],
    skip: 1,
    sort: "COLUMN_NAME",
    groupBy: "COLUMN_NAME"
});
```

## Simple query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find:{
        "first_name": "Bob"
    }
});
```

## Simple [headers]

**headers**

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

## Simple [select]

**select**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find:{
        "first_name": "Bob"
    },
    select: "first_name"
});
```

## Simple [limit]

**limit**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find:{
        "first_name": "Bob"
    },
    limit: 2
});
```

## Simple [skip]

**skip**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find:{
        "first_name": "Bob"
    },
    skip: 1
});
```

## Simple [sort]

**sort**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find:{
        "first_name": "Bob"
    },
    sort: "first_name"
});
```

## Simple [deep]

**deep**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find:{
        "first_name": "Bob"
    },
    deep: [
        {
            s_key: "customer_id",
            t_col: "products",
            t_key: "owner_id",
            select: "customer_id,first_name"
        }
    ]
});
```

## $lt query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        customer_id: {
            "$lt": 2
        }
    }
});
```

## $lte query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        customer_id: {
            "$lte": 2
        }
    }
});
```

## $gt query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        customer_id: {
            "$gt": 2
        }
    }
});
```

## $gte query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        customer_id: {
            "$gte": 2
        }
    }
});
```

## $eq query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        customer_id: {
            "$eq": 2
        }
    }
});
```

## $ne query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        customer_id: {
            "$ne": 2
        }
    }
});
```

## $not query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        customer_id: {
            "$not": {
                "$in": [1, 2, 3, 4]
            }
        }
    }
});
```

## $and query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        "$and": [
            {
                "customer_id": 2
            },
            {
                "pincode": 7171
            }
        ]
    }
});
```

## $or query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        "$or": [
            {
                "customer_id": 2
            },
            {
                "pincode": 7171
            }
        ]
    }
});
```

## $in query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        "customer_id": {
            "$in": [1, 2]
        }
    }
});
```

## $nin query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        "customer_id": {
            "$nin": [1, 2]
        }
    }
});
```

## $like query
```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        "first_name": {
            "$like": "Bob%"
        }
    }
});
```

## MongoDB $in operator in nested find

**$in operator in nested find**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        "eventListeners.versions.name": {
            "$in": [
                "Original",
                "1"
            ]
        }
    }
});
```

## MongoDB $nin operator in nested find

**$nin operator in nested find**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        "eventListeners.versions.name": {
            "$nin": [
                "Original",
                "1"
            ]
        }
    }
});
```

## MongoDB $and operator in nested find

**$and operator in nested find**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        "$and": [
            {
                "eventListeners.versions.name": "Original"
            },
            {
                "eventListeners.versions.version": "-1"
            }
        ]
    }
});
```

## MongoDB $or operator in nested find

**$or operator in nested find**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "mysql_8",
    database: "inventory",
    collection: "customers",
    find: {
        "$or": [
            {
                "eventListeners.versions.name": "Original"
            },
            {
                "eventListeners.versions.version": "-1"
            }
        ]
    }
});
```

## 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.

**Query the customers of the tenant acme**

```typescript
let query = await g.sys.db.gen.queryGen({
    instance: "crm::acme", database: "crm", collection: "customers",
    find: {
        "first_name": "Bob"
    },
    sort: "customer_id",
    limit: 10
});
```

## Related

- [Query for get data generated API](https://docs.apimaker.dev/v1/docs/apis-all/generated-apis/auto-generated-query-for-get-data-api.html) · [Schema API from code](https://docs.apimaker.dev/v1/examples/sys/db/query.html) · [The global object g](https://docs.apimaker.dev/v1/docs/pre-defined-terms/global-object-g.html)