Hello Everyone,

In this blog we will discuss about how to update multiple array elements in MongoDb using a single query.

Let say we have a collection in MongoDb named "Form" which consists of the below available documents:

> db.Form.find().pretty()
{
    "_id" : ObjectId("5637345bb8bd53700e2ec054"),
    "title" : "Customer Complaints",
    "formData" : [
        {
            "minimise" : true,
            "label" : "test",
            "value" : "",
            "type" : "textInput",
            "required" : false,
            "description" : "Eg.Josh",
            "metaData" : {
                "placeholder" : "Enter name"
            }
        },
        {
            "label" : "test",
            "value" : "",
            "type" : "textArea",
            "required" : false,
            "description" : "eg.street one",
            "metaData" : {
                "placeholder" : "placeholder"
            }
        },
        {
            "label" : "test",
            "value" : "",
            "type" : "select",
            "required" : false,
            "description" : "description",
            "metaData" : {
                "placeholder" : "placeholder",
                "options" : [
                    "Male",
                    "Female"
                ]
            }
        }
    ],
    "userId" : "sf12h12a412s",
    "userName" : "Ankit Chettri"
}
{
    "_id" : ObjectId("56373832b8bd53700e2ec057"),
    "title" : "User requirements",
    "formData" : [
        {
            "label" : "test",
            "value" : null,
            "type" : "sliderInput",
            "required" : false,
            "description" : "Range",
            "metaData" : {
                "ceiling" : 10000,
                "floor" : 1000,
                "step" : "1000"
            }
        },
        {
            "label" : "test",
            "value" : "",
            "type" : "switchInput",
            "required" : false,
            "description" : "options",
            "metaData" : {
                "switch_value_one" : "Yes",
                "switch_value_two" : "No"
            }
        }
    ],
    "userId" : "sf12h12a412s",
    "userName" : "Ankit Chettri"
}

If you want to update the content of label of multiple array elements in the above (Form)documents in one query below is the query:-

 db.Form.find().forEach(function (Form) {Form.formData.forEach(function (formData) {formData.label="Name";db.Form.save(Form);});})

Output

> db.Form.find().pretty()
{
    "_id" : ObjectId("5637345bb8bd53700e2ec054"),
    "title" : "Customer Complaints",
    "formData" : [
        {
            "minimise" : true,
            "label" : "Name",
            "value" : "",
            "type" : "textInput",
            "required" : false,
            "description" : "Eg.Josh",
            "metaData" : {
                "placeholder" : "Enter name"
            }
        },
        {
            "label" : "Name",
            "value" : "",
            "type" : "textArea",
            "required" : false,
            "description" : "eg.street one",
            "metaData" : {
                "placeholder" : "placeholder"
            }
        },
        {
            "label" : "Name",
            "value" : "",
            "type" : "select",
            "required" : false,
            "description" : "description",
            "metaData" : {
                "placeholder" : "placeholder",
                "options" : [
                    "Male",
                    "Female"
                ]
            }
        }
    ],
    "userId" : "sf12h12a412s",
    "userName" : "Ankit Chettri"
}
{
    "_id" : ObjectId("56373832b8bd53700e2ec057"),
    "title" : "User requirements",
    "formData" : [
        {
            "label" : "Name",
            "value" : null,
            "type" : "sliderInput",
            "required" : false,
            "description" : "Range",
            "metaData" : {
                "ceiling" : 10000,
                "floor" : 1000,
                "step" : "1000"
            }
        },
        {
            "label" : "Name",
            "value" : "",
            "type" : "switchInput",
            "required" : false,
            "description" : "options",
            "metaData" : {
                "switch_value_one" : "Yes",
                "switch_value_two" : "No"
            }
        }
    ],
    "userId" : "sf12h12a412s",
    "userName" : "Ankit Chettri"
}