Class: Query

ClearBlade. Query

new Query(options)

creates a Query object that can be used in Collection methods or on its own to operate on items on the server
Parameters:
Name Type Description
options Object Object that has configuration values used when instantiating a Query object
Source:

Methods

equalTo(field, value)

Creates an equality clause in the query object
Parameters:
Name Type Description
field String String defining what attribute to compare
value String String or Number that is used to compare against
Source:
Example

Adding an equality clause to a query

var query = new ClearBlade.Query();
query.equalTo('name', 'John');
//will only match if an item has an attribute 'name' that is equal to 'John'

fetch(callback)

Reqests an item or a set of items from the query. Requires that the Query object was initialized with a collection.
Parameters:
Name Type Description
callback function Supplies processing for what to do with the data that is returned from the collection
Source:
Examples

The typical callback

var callback = function (err, data) {
    if (err) {
        //error handling
    } else {
        console.log(data);
    }
};

Fetching data from a collection

var returnedData = [];
var callback = function (err, data) {
    if (err) {
        throw new Error (data);
    } else {
        returnedData = data;
    }
};

query.fetch(callback);
//this will give returnedData the value of what ever was returned from the server.

greaterThan(field, value)

Creates a greater than clause in the query object
Parameters:
Name Type Description
field String String defining what attribute to compare
value String String or Number that is used to compare against
Source:
Example

Adding a greater than clause to a query

var query = new ClearBlade.Query();
query.greaterThan('age', 21);
//will only match if an item has an attribute 'age' that is greater than 21

greaterThanEqualTo(field, value)

Creates a greater than or equality clause in the query object
Parameters:
Name Type Description
field String String defining what attribute to compare
value String String or Number that is used to compare against
Source:
Example

Adding a greater than or equality clause to a query

var query = new ClearBlade.Query();
query.greaterThanEqualTo('age', 21);
//will only match if an item has an attribute 'age' that is greater than or equal to 21

lessThan(field, value)

Creates a less than clause in the query object
Parameters:
Name Type Description
field String String defining what attribute to compare
value String String or Number that is used to compare against
Source:
Example

Adding a less than clause to a query

var query = new ClearBlade.Query();
query.lessThan('age', 50);
//will only match if an item has an attribute 'age' that is less than 50

lessThanEqualTo(field, value)

Creates a less than or equality clause in the query object
Parameters:
Name Type Description
field String String defining what attribute to compare
value String String or Number that is used to compare against
Source:
Example

Adding a less than or equality clause to a query

var query = new ClearBlade.Query();
query.lessThanEqualTo('age', 50);
//will only match if an item has an attribute 'age' that is less than or equal to 50

notEqualTo(field, value)

Creates a not equal clause in the query object
Parameters:
Name Type Description
field String String defining what attribute to compare
value String String or Number that is used to compare against
Source:
Example

Adding a not equal clause to a query

var query = new ClearBlade.Query();
query.notEqualTo('name', 'Jim');
//will only match if an item has an attribute 'name' that is not equal to 'Jim'

or(that)

chains an existing query object to the Query object in an or
Parameters:
Name Type Description
that Query Query object that will be added in disjunction to this query object
Source:
Example

Chaining two queries together in an or

var query1 = new ClearBlade.Query();
var query2 = new ClearBlade.Query();
query1.equalTo('name', 'John');
query2.equalTo('name', 'Jim');
query1.or(query2);
//will match if an item has an attribute 'name' that is equal to 'John' or 'Jim'

remove(callback)

Removes an item or set of items from the Query
Parameters:
Name Type Description
callback function Function that handles the response from the server
Source:
Example

Removing an item in a collection

//This example assumes that you have a collection with the item whose 'name' attribute is 'John'
var query = new ClearBlade.Query({'collection': 'COLLECTIONID'});
query.equalTo('name', 'John');
var callback = function (err, data) {
    if (err) {
        throw new Error (data);
    } else {
        console.log(data);
    }
};

query.remove(callback);
//removes every item whose 'name' attribute is equal to 'John'

update(changes, callback)

Updates an existing item or set of items. Requires that a collection was set when the Query was initialized.
Parameters:
Name Type Description
changes Object Object representing the attributes that you want changed
callback function Function that handles the response of the server
Source:
Example

Updating a set of items

//This example assumes a collection of items that have the columns name and age.
var query = new ClearBlade.Query({'collection': 'COLLECTIONID'});
query.equalTo('name', 'John');
var changes = {
    age: 23
};
var callback = function (err, data) {
    if (err) {
        throw new Error (data);
    } else {
        console.log(data);
    }
};

query.update(changes, callback);
//sets John's age to 23