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MongoDB

MongoDB is a document-oriented NoSQL database used for high-volume data storage. It doesn't store the data in the form of tables and rows as in traditional relational databases. Instead, it stores the data in collections and documents in a JSON format (using key-value pairs).

{% hint style="warning" %} The following document assumes that you understand the basics of connecting to databases on Appsmith. If not, please go over them before reading further. {% endhint %}

Connection Settings

Appsmith needs the following parameters for connecting to a Mongo database:

{% hint style="success" %} All required fields are suffixed with an asterisk (*). {% endhint %}

Connection

To set up a connection, fill in the following parameters:

  • Connection Mode*: You must choose one of the following two modes:
    • Read Only: Choosing this mode gives Appsmith read-only permission on the database. This only allows you to fetch data from the database.
    • Read / Write: Choosing this mode gives Appsmith both read and write permissions on the database. This allows you to execute all CRUD queries.
  • Connection Type*: You must choose one of the following connection types:
    • Direct Connection: Choose this connection type to connect directly to a mongo instance
    • Replicate Set: Choose this connection type to connect to a set of mongo instances.
  • Host Address / Port*: Fill in the database host’s address and port. If you don’t specify a port, Appsmith will try to connect to port 27017. You can specify multiple host addresses for a replicate set. If you have an SRV URI, please follow these steps to connect to your MongoDB instance.
  • Default Database Name*: Fill in the name of the database you want to connect to. This is your database’s name on your mongo server.

Authentication

For authentication, fill in the following parameters:

  • Database Name: Fill in the name of the database against which you want to authenticate. This is typically admin for most MongoDB instances.
  • Authentication Type*: Choose the authentication mechanism to connect to your database. This can be one of SCRAM-SHA-1, SCRAM-SHA-256, or MONGO-CR.
  • Username: Fill in the username required for authenticating connection requests to your database. Set this to empty if you won't want to specify a username to authenticate with.
  • Password: Fill password required for authenticating connection requests for the given username to the database. Set this to empty if you want to log in without a password (please ensure your database accepts such connections).

SSL

The SSL Mode can be set to one of the following values:

  • Default: Depends on Connection Type. If using the Replica set, this is Enabled. If using a Direct connection, this is Disabled.
  • Enabled: Reject connection (if SSL is not available).
  • Disabled: Connect without SSL, use a plain unencrypted connection.

Connect using SRV URI

The Service Record URI (SRV URI) comprises of following components. For example, the SRV URI can be represented as below:

{% hint style="warning" %} mongodb+srv://<your_username>:<your_password>@<host_name_or_connection_url>/<authDBName> {% endhint %}

The fields from the URI can be mapped as below:

  • <connection_url> to the Host Address field
  • <defaultDbName> to the Default Database Name field
  • <your_username> to the Username field
  • <your_password> to the Password field
  • <authDbName> to the Database Name field under the Authentication sub-section.

Read more on MongoDB documentation.

Querying Mongo (Form Input)

Form input provides an easy interface to query the Mongo database.

As part of Form Input, Appsmith supports queries like Find one or more documents, Insert a document, Update one, Count, and more.

{% hint style="info" %} All mongo queries return an array of objects where each object is a mongo document, and the object's properties are the document's keys. {% endhint %}

1. Find Document(s)

This command selects documents in a collection or view. The following fields are supported in Appsmith for this command :

Collection Name: The name of the collection or view to query. The input is expected in a string format like the following :

restaurants

Query: The query predicate. If unspecified, then all documents in the collection will match the predicate. The input is expected in JSON/BSON format like the following :

{
     rating: { $gte: 9 }, 
     cuisine: "italian" 
}

Sort : (Optional) The sort specification for ordering the results. The input is expected in JSON/BSON format like the following :

{ name: 1 }

Projection : (Optional) The projection specification determines which fields to include in the returned documents. The input is expected in JSON/BSON format like the following :

{ name: 1, rating: 1, address: 1 }

Limit : (Optional) The maximum number of documents to return. If unspecified, then defaults to 10 documents. The input is expected in number format :

10

Skip : (Optional) Number of documents to skip. Defaults to 0. The input is expected in number format :

0

2. Insert Document(s)

This command inserts one or more documents and returns a document containing the status of all inserts. The following fields are supported in Appsmith for this command :

Collection Name: The name of the target collection. The input is expected in a string format like the following :

users

Documents: An array of one or more documents to insert into the named collection. The input is expected in a JSON/BSON Array format like the following :

[ { _id: 1, user: "abc123", status: "A" } ]

3. Update Document(s)

This command modifies multiple documents in a collection. The following fields are supported in Appsmith for this command :

Collection Name: The collection against which to run the command. The input is expected in a string format like the following :

people

Query: The query that matches documents to update. The input is expected in JSON/BSON format like the following :

{ name: "Andy" }

Update: The modifications to apply. The input is expected in JSON/BSON format like the following :

{ $inc: { score: 1 } }

Limit: The dropdown is used to configure if this delete command should act upon a single document or if this command should delete all the matching documents according to the query.

4. Delete Document(s)

This command removes documents from a collection. The following fields are supported in Appsmith for this command :

Collection Name: The target collection against which to run the command. The input is expected in a string format like the following :

orders

Query: The query that matches document(s) to delete. The input is expected in JSON/BSON format like the following :

{ status: "D" }

Limit: The dropdown is used to configure if this delete command should act upon a single document or if this command should delete all the matching documents according to the query.

5. Count

This command counts the number of documents in a collection or a view. Returns a document that contains this count. The following fields are supported in Appsmith for this command :

Collection Name: The name of the collection or view to count. The input is expected in a string format like the following :

orders

Query: A query that selects which documents to count in the collection or view. The input is expected in JSON/BSON format like the following :

{ ord_dt: { $gt: new Date('01/01/2021') }

6. Distinct

This command finds the distinct values for a specified field across a single collection. The following fields are supported in Appsmith for this command :

Collection Name: The name of the collection to query for distinct values. The input is expected in a string format like the following :

inventory

Query: A query specifies documents from which to retrieve the distinct values. The input is expected in JSON/BSON format like the following :

{ dept: "A"} }

Key/Field: The field for which to return distinct values. The input is expected in a string format like the following :

item.sku

7. Aggregate

This command performs aggregation operation using the aggregation pipeline. The pipeline allows users to process data from a collection or other source with a sequence of stage-based manipulations. The following fields are supported in Appsmith for this command :

Collection Name: The name of the collection or view that acts as the input for the aggregation pipeline. The input is expected in a string format like the following :

articles

Array of Pipelines: An array of aggregation pipeline stages that process and transform the document stream as part of the aggregation pipeline. The input is expected in JSON/BSON array format like the following :

[
      { $project: { tags: 1 } },
      { $unwind: "$tags" },
      { $group: { _id: "$tags", count: { $sum : 1 } } }
]

The above example performs an aggregate operation on the articles collection to calculate the count of each distinct element in the tags array that appears in the collection.

Querying Mongo (Advanced)

You can use a Raw command to write your custom Mongo queries.

{% hint style="warning" %} The mongo database command syntax is slightly different from the mongo collection methods you may be familiar with. Read more. {% endhint %}

To add a Raw query, set your query parameters as below:

  • Commands - Select Command as Raw.
  • Query palette - Add the Raw query to it.
  • Click Run to test your query.

How to create a Raw Query?

{% hint style="info" %} All mongo queries return an array of objects where each object is a mongo document, and the object's properties are the document's keys. {% endhint %}

The pipeline is an array that contains the aggregation stages that process the documents. In your Raw query, you'll have to include the filter criteria in a pipeline keyword when using aggregation. For example, you wish to fetch data from movies where the revenue is 42600000. You'll use $match that checks for documents where the revenue is 42600000. You added the below query:

{
   "aggregate":"movies",
   "$lookup":[
      {
         "$match":{
            "revenue":42600000
         }
      }
   ],
   "cursor":{
      "batchSize":10
   }
}

{% hint style="info" %} By default, Mongo returns only 101 records due to its default batchSize. You can update the limit and batchSize by adding values to your query. {% endhint %}

  • Click the Run button to execute the query.

The queries will fail to execute and throw an exception Pipeline option must be specified as an array.

The error generated when the pipeline keyword  is not added

  • For Raw queries, you'll have to add the filter criteria to the pipeline keyword as below:
{
   "aggregate":"movies",
   "pipeline":[
      {
         "$match":{
            "revenue":42600000
         }
      }
   ],
   "cursor":{
      "batchSize":10
   }
}
  • Click the Run button to execute the query.

A raw query response

Template Queries

Appsmith provides template queries to help with the syntax.

Using Queries in applications

Once you have successfully run a Query, you can use it in your application to