Class: Query

ClearBlade.Query

new Query(options) → {Object}

creates and returns 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:
Returns:
Clearblade.Query the created query
Type
Object

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

fetch(callback) → {ClearBlade.Item}

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:
Returns:
An array of ClearBlade Items
Type
ClearBlade.Item
Example

The typical callback

var query = ClearBlade.Query({'collection': 'COLLECTIONID'});
var callback = function (err, data) {
    if (err) {
        //error handling
    } else {
        console.log(data);
    }
};
query.fetch(callback);

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

matches(field, pattern)

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

Adding an regex matching clause to a query

var query = ClearBlade.Query();
query.matches('name', 'Smith$');
//will only match if an item has an attribute 'name' that That ends in 'Smith'

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 = 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 = ClearBlade.Query();
var query2 = 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 = 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'

setPage(pageSize, pageNum)

Set the pagination options for a Query.
Parameters:
Name Type Description
pageSize int Number of items per response page. The default is 100.
pageNum int Page number, taking into account the page size. The default is 1.
Source:

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 = 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