DataObjectTag

DataObjectTag

Represents a collection of values associated with a data object e.g. a collection of tags of an article, a set of skills of a person etc.

This association may be defined in a field of a data model as follows: 


 {
     "name": "Person", "title": "Persons", "inherits":"Party", "version": "1.1",
     "fields": [
        ...
        {
            "@id": "https://themost.io/skills",
            "name": "skills",
            "title": "Skills",
            "description": "A collection of skills of this person.",
            "many": true,
            "type": "Text"
        }
        ...
     ]
     }

where model [Person] has a one-to-many association with a collection of strings in order to define the skills of a person.

An instance of DataObjectTag class overrides DataQueryable methods for filtering associated values: 


 var persons = context.model('Person');
 persons.where('email').equal('veronica.fletcher@example.com')
     .getTypedItem().then(function(person) {
            person.property('skills').all().then(function(result) {
                return done(null, result);
            });
        }).catch(function(err) {
            return done(err);
        });

Insert item(s): 


 var persons = context.model('Person');
 persons.where('email').equal('veronica.fletcher@example.com')
     .getTypedItem().then(function(person) {
                person.property('skills').insert([
                    "node.js",
                    "C#.NET",
                    "PHP"
                ]).then(function() {
                    return done();
                });
            }).catch(function(err) {
                return done(err);
            });

Remove item(s): 


 var persons = context.model('Person');
 persons.where('email').equal('veronica.fletcher@example.com')
 .getTypedItem().then(function(person) {
                person.property('skills').remove([
                    "C#.NET"
                ]).then(function() {
                    return done();
                });
            }).catch(function(err) {
                return done(err);
            });

Constructor

new DataObjectTag(obj, association)

Parameters:
Name Type Description
obj DataObject An object which represents the parent data object
association String | * A string that represents the name of the field which holds association mapping or the association mapping itself.
Properties:
Name Type Description
baseModel DataModel The model associated with this data object junction
parent DataObject Gets or sets the parent data object associated with this instance of DataObjectTag class.
mapping DataAssociationMapping Gets or sets the mapping definition of this data object association.
Source:

Extends

Methods

add(x) → {DataQueryable}

Prepares an addition (e.g. ([field] + 4))
Parameters:
Name Type Description
x number | * The
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of products
 context.model('Product')
 .select('id','name', 'price')
 //perform ((ProductData.price + 100)>300)
 .where('price').add(100).lowerThan(300)
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

all(callbackopt) → {Deferred|*}

Parameters:
Name Type Attributes Description
callback function <optional>
Inherited From:
Source:
Returns:
- If callback function is missing returns a promise.
Type
Deferred | *

alsoSelect(attr) → {DataQueryable}

Adds a field or an array of fields to select statement
Parameters:
Name Type Description
attr String | Array | DataField | *
Inherited From:
Deprecated:
  • Yes
Source:
Returns:
Type
DataQueryable

and(attr) → {DataQueryable}

Prepares a logical AND expression
Parameters:
Name Type Description
attr string The name of field that is going to be used in this expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
context.model('Order').where('customer').equal(298)
 .and('orderStatus').equal(1)
 .list().then(function(result) {
        //SQL: WHERE ((OrderData.customer=298) AND (OrderData.orderStatus=1)
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

asArray(valueopt) → {DataQueryable}

Parameters:
Name Type Attributes Description
value Boolean <optional>
Inherited From:
Source:
Returns:
Type
DataQueryable

average(attr, callbackopt) → {Deferred|*}

Executes the query against the current model and returns the average value of the given attribute.
Parameters:
Name Type Attributes Description
attr string A string that represents a field of the current model
callback function <optional>
 A callback function where the first argument will contain the Error object if an error occured, or null otherwise. The second argument will contain the result, if any.
Inherited From:
Source:
Returns:
- If callback parameter is missing then returns a Deferred object.
Type
Deferred | *
Example
//retrieve the average price of products sold during last month
 context.model('Order')
 .where('orderDate').greaterOrEqual(moment().startOf('month').toDate())
 .average('orderedItem/price').then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

between(value1, value2) → {DataQueryable}

Prepares a comparison where the left operand is between two values
Parameters:
Name Type Description
value1 * The minimum value
value2 * The maximum value
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve products where price is between 150 and 250
 context.model('Product')
 .where('price').between(150,250)
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//The result set of this example may be:
 id   name                                        model   price
 ---  ------------------------------------------  ------  ------
 367  Asus Transformer Book T100                  HD2895  224.52
 380  Zotac Zbox Nano XS AD13 Plus                WC5547  228.05
 384  Apple iPad Air                              ZE6015  177.44
 401  Intel Core i7-4960X Extreme Edition         SM5853  194.61
 440  Bose SoundLink Bluetooth Mobile Speaker II  HS5288  155.27

bit(value, resultopt) → {DataQueryable}

Prepares a bitwise and comparison.
Parameters:
Name Type Attributes Description
value * The right operand of the express
result Number <optional>
 The result of a bitwise and expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of permissions for model Person and insert permission mask (2)
 context.model('Permission')
 //prepare bitwise AND (((PermissionData.mask & 2)=2)
 .where('mask').bit(2)
 .and('privilege').equal('Person')
 .and('parentPrivilege').equal(null)
 .list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

cache(valueopt) → {string|DataQueryable}

Gets or sets a boolean which indicates whether results should be cached or not. This parameter is valid for models which have caching mechanisms.
Parameters:
Name Type Attributes Description
value string <optional>
Inherited From:
Source:
Returns:
Type
string | DataQueryable

ceil() → {DataQueryable}

Prepares a ceil mathematical expression
Inherited From:
Source:
Returns:
Type
DataQueryable

clear(callbackopt)

Removes all values
Parameters:
Name Type Attributes Description
callback function <optional>
Deprecated:
  • - This method is deprecated. Use removeAll() method instead
Source:

clone() → {DataQuerable|*}

Clones the current DataQueryable instance.
Inherited From:
Source:
Returns:
- The cloned object.
Type
DataQuerable | *

concat(s) → {DataQueryable}

Prepares a string concatenation expression
Parameters:
Name Type Description
s string
Inherited From:
Source:
Returns:
Type
DataQueryable

contains(value) → {DataQueryable}

Prepares a contains comparison (e.g. a string contains another string).
Parameters:
Name Type Description
value * The right operand of the expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve person where the given name contains
 context.model('Person').select(['id','givenName','familyName'])
 .where('givenName').contains('ex')
 .list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//The result set of this example may be:
 id   givenName  familyName
 ---  ---------  ----------
 297  Alex       Miles
 353  Alexis     Rees

count(callbackopt) → {Deferred|*}

Executes the query against the current model and returns the count of items found.
Parameters:
Name Type Attributes Description
callback function <optional>
 A callback function where the first argument will contain the Error object if an error occured, or null otherwise. The second argument will contain the result, if any.
Inherited From:
Source:
Returns:
- If callback parameter is missing then returns a Deferred object.
Type
Deferred | *
Example
//retrieve the number of a product's orders
 context.model('Order')
 .where('orderedItem').equal(302)
 .count().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

countOf(name, aliasopt) → {*|QueryField}

Parameters:
Name Type Attributes Description
name string
alias string <optional>
Inherited From:
Source:
Returns:
Type
* | QueryField

data(nameopt, valueopt) → {DataQueryable|*}

Gets or sets query data. This data may be used in before and after execute listeners.
Parameters:
Name Type Attributes Description
name string <optional>
value * <optional>
Inherited From:
Source:
Returns:
Type
DataQueryable | *

divide(x) → {DataQueryable}

Prepares a division (e.g. ([field] / 0.2))
Parameters:
Name Type Description
x number
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of orders
 context.model('Product')
 .select('id','name', 'price')
 //perform ((ProductData.price / 0.8)>500)
 .where('price').divide(0.8).greaterThan(500)
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

endsWith(obj) → {DataQueryable}

Prepares an ends with comparison
Parameters:
Name Type Description
obj * The string to be searched for at the end of a field.
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve people whose given name ends with 'y'
 context.model('Person')
 .where('givenName').endsWith('y')
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//Results
 id   givenName  familyName
 ---  ---------  ----------
 257  Daisy      Lambert
 287  Zachary    Field
 295  Anthony    Berry
 339  Brittney   Hunt
 341  Kimberly   Wheeler

equal(obj) → {DataQueryable}

Performs an equality comparison.
Parameters:
Name Type Description
obj * The right operand of the expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of orders with order status equal to 1
 context.model('Order').where('orderStatus').equal(1)
 .list().then(function(result) {
        //WHERE (OrderData.orderStatus=1)
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

expand(attr) → {DataQueryable}

Sets an expandable field or collection of fields. An expandable field produces nested objects based on the association between two models.
Parameters:
Name Type Description
attr string | * A param array of strings which represents the field or the array of fields that are going to be expanded. If attr is missing then all the previously defined expandable fields will be removed.
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve an order and expand customer field
 context.model('Order')
 //note: the field [orderedItem] is defined as expandable in model definition and it will produce a nested object for each order
 .select('id','orderedItem','customer')
 .expand('customer')
 .where('id').equal(46)
 .first().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//Result:
 {
    "id": 46,
    "orderedItem": {
        "id": 413,
        "additionalType": "Product",
        "category": "Storage and Networking Gear",
        "price": 647.13,
        "model": "FY8135",
        "releaseDate": "2015-01-15 18:07:42.000+02:00",
        "name": "LaCie Blade Runner",
        "dateCreated": "2015-11-23 14:53:04.927+02:00",
        "dateModified": "2015-11-23 14:53:04.934+02:00"
    },
    "customer": {
        "id": 317,
        "additionalType": "Person",
        "alternateName": null,
        "description": "Nicole Armstrong",
        "image": "https://s3.amazonaws.com/uifaces/faces/twitter/zidoway/128.jpg",
        "dateCreated": "2015-11-23 14:52:57.886+02:00",
        "dateModified": "2015-11-23 14:52:57.917+02:00"
    }
}
 
//retrieve an order and do not expand customer field
 {
    "id": 46,
    "orderedItem": {
        "id": 413,
        "additionalType": "Product",
        "category": "Storage and Networking Gear",
        "price": 647.13,
        "model": "FY8135",
        "releaseDate": "2015-01-15 18:07:42.000+02:00",
        "name": "LaCie Blade Runner",
        "dateCreated": "2015-11-23 14:53:04.927+02:00",
        "dateModified": "2015-11-23 14:53:04.934+02:00"
    },
    "customer": 317
}

fieldOf(attr, aliasopt) → {DataQueryable|QueryField|*}

Parameters:
Name Type Attributes Description
attr string | *
alias string <optional>
Inherited From:
Source:
Returns:
Type
DataQueryable | QueryField | *

first(callbackopt) → {Deferred|*}

Executes the specified query against the underlying model and returns the first item.
Parameters:
Name Type Attributes Description
callback function <optional>
 A callback function where the first argument will contain the Error object if an error occured, or null otherwise. The second argument will contain the result.
Inherited From:
Source:
Returns:
Type
Deferred | *
Example
//retrieve an order by id
 context.model('Order')
 .where('id').equal(302)
 .first().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

flatten(valueopt) → {DataQueryable}

Disables expandable fields
Parameters:
Name Type Attributes Description
value boolean <optional>
 If the value is true the result will contain only flat objects -without any nested associated object-, even if model definition contains expandable fields. If value is missing, the default parameter is true
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve a list of orders
 context.model('Order')
 .flatten()
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//Results:
 id  customer  orderStatus  paymentMethod
 --  --------  -----------  -------------
 1   299       5            6
 2   337       7            5
 3   309       3            3
 4   257       2            4
 5   285       5            2

floor() → {DataQueryable}

Prepares a floor mathematical expression
Inherited From:
Source:
Returns:
Type
DataQueryable

getBaseModel() → {DataModel}

Gets an instance of DataModel class which represents the data adapter of this association
Source:
Returns:
Type
DataModel

getDate() → {DataQueryable}

Prepares an expression by getting the date only value of a datetime field
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of orders
 context.model('Order')
 .select('id','paymentDue', 'orderDate')
 .where('orderDate').getDate().equal('2015-01-16')
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

getDay() → {DataQueryable}

Prepares an expression by getting the day of the month of a datetime field
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of orders
 context.model('Order')
 .where('orderDate').getYear().equal(2015)
 .and('orderDate').getMonth().equal(1)
 .and('orderDate').getDay().equal(16)
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

getFullYear() → {DataQueryable}

Prepares an expression by getting the year of a datetime field
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of orders made during 2015
 context.model('Order')
 .where('orderDate').getYear().equal(2015)
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

getHours() → {DataQueryable}

Prepares an expression by getting the hours (from 0 to 23) a datetime field
Inherited From:
Source:
Returns:
Type
DataQueryable

getItem() → {Promise|*}

Executes the specified query against the underlying model and returns the first item.
Inherited From:
Source:
Returns:
Type
Promise | *

getItems() → {Promise|*}

Inherited From:
Source:
Returns:
Type
Promise | *

getLevels() → {number}

Gets the number of levels of the expandable objects
Inherited From:
Source:
Returns:
Type
number

getMinutes() → {DataQueryable}

Prepares an expression by getting the minutes (from 0 to 59) a datetime field
Inherited From:
Source:
Returns:
Type
DataQueryable

getMonth() → {DataQueryable}

Prepares an expression by getting the month (from 1 to 12) of a datetime field.
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of orders made during October 2015
 context.model('Order')
 .where('orderDate').getYear().equal(2015)
 .and('orderDate').getMonth().equal(10)
  .take(5).list().then(function(result) {
        console.table(result.records);
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

getSeconds() → {DataQueryable}

Prepares an expression by getting the seconds (from 0 to 59) a datetime field
Inherited From:
Source:
Returns:
Type
DataQueryable

getTypedItem() → {Promise|*}

Gets an instance of DataObject by executing the defined query.
Inherited From:
Source:
Returns:
Type
Promise | *

getTypedItems() → {Promise|*}

Gets a collection of DataObject instances by executing the defined query.
Inherited From:
Source:
Returns:
Type
Promise | *

getTypedList() → {Promise|*}

Gets a result set that contains a collection of DataObject instances by executing the defined query.
Inherited From:
Source:
Returns:
Type
Promise | *

getYear() → {DataQueryable}

Prepares an expression by getting the year of a datetime field
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of orders made during 2015
 context.model('Order')
 .where('orderDate').getYear().equal(2015)
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

greaterOrEqual(obj) → {DataQueryable}

Prepares a greater than or equal comparison.
Parameters:
Name Type Description
obj * The right operand of the expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of orders where product price is greater than or equal to 800
 context.model('Order')
 .where('orderedItem/price').greaterOrEqual(800)
 .orderByDescending('orderDate')
 .take(5)
 .list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

greaterThan(obj) → {DataQueryable}

Prepares a greater than comparison.
Parameters:
Name Type Description
obj * The right operand of the expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve a list of orders where product price is greater than 800
 context.model('Order')
 .where('orderedItem/price').greaterThan(800)
 .orderByDescending('orderDate')
 .select('id','orderedItem/name as productName', 'orderedItem/price as productPrice', 'orderDate')
 .take(5)
 .list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//Results:
 id   productName                                   productPrice  orderDate
 ---  --------------------------------------------  ------------  -----------------------------
 304  Apple iMac (27-Inch, 2013 Version)            1336.27       2015-11-27 23:49:17.000+02:00
 322  Dell B1163w Mono Laser Multifunction Printer  842.86        2015-11-27 20:16:52.000+02:00
 167  Razer Blade (2013)                            1553.43       2015-11-27 04:17:08.000+02:00
 336  Apple iMac (27-Inch, 2013 Version)            1336.27       2015-11-26 07:25:35.000+02:00
 89   Nvidia GeForce GTX 650 Ti Boost               1625.49       2015-11-21 17:29:21.000+02:00

groupBy(…attr) → {DataQueryable}

Prepares a group by expression
Parameters:
Name Type Attributes Description
attr string <repeatable>
 A param array of string that represents the attributes which are going to be used in group by expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve products with highest sales during last month
 context.model('Order')
 .select('orderedItem/model as productModel', 'orderedItem/name as productName','count(id) as orderCount')
 .where('orderDate').greaterOrEqual(moment().startOf('month').toDate())
 .groupBy('orderedItem')
 .orderByDescending('count(id)')
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//Results
 productModel  productName                              orderCount
 ------------  ---------------------------------------  ----------
 SM5111        Brother MFC-J6920DW                      3
 FY8135        LaCie Blade Runner                       3
 HA6910        Apple iMac (27-Inch, 2013 Version)       2
 LD4238        Dell XPS 18                              2
 HR6205        Samsung Galaxy Note 10.1 (2014 Edition)  2

in(objs) → {DataQueryable}

Prepares a typical IN comparison.
Parameters:
Name Type Description
objs Array An array of values which represents the values to be used in expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve orders with order status 1 or 2
 context.model('Order').where('orderStatus').in([1,2])
 .list().then(function(result) {
        //WHERE (OrderData.orderStatus IN (1, 2))
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

indexOf(s) → {DataQueryable}

Prepares an indexOf comparison
Parameters:
Name Type Description
s string The string to search for
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve a list of persons
 context.model('Person')
 .select('givenName')
 .where('givenName').indexOf('a').equal(1)
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//Results:
 givenName
 ---------
 Daisy
 Maxwell
 Mackenzie
 Zachary
 Mason

insert(callbackopt)

Inserts an array of values
Parameters:
Name Type Attributes Description
callback function <optional>
Source:
Example
context.model('Person').where('email').equal('veronica.fletcher@example.com')
 .getTypedItem().then(function(person) {
        person.property('skills').insert([
            "node.js",
            "C#.NET"
        ]).then(function() {
            return done();
        });
    }).catch(function(err) {
        return done(err);
    });

is(obj) → {DataQueryable}

Performs an equality comparison.
Parameters:
Name Type Description
obj * The right operand of the expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a person with id equal to 299
 context.model('Person').where('id').is(299)
 .first().then(function(result) {
        //WHERE (PersonData.id=299)
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

length() → {DataQueryable}

Prepares a string length expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve a list of persons
 context.model('Person')
 .select('givenName')
 .where('givenName').length().equal(5)
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//Results:
 givenName
 ---------
 Daisy
 Peter
 Kylie
 Colin
 Lydia

levels(valueopt) → {DataQueryable}

Sets the number of levels of the expandable attributes. The default value is 1 which means that any expandable attribute will be flat (without any other nested attribute). If the value is greater than 1 then the nested objects may contain other nested objects and so on.
Parameters:
Name Type Attributes Description
value Number <optional>
 A number which represents the number of levels which are going to be used in expandable attributes.
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//get orders, expand customer and get customer's nested objects if any.
 context.model('Order')
 .orderByDescending('dateCreated)
 .expand('customer')
 .levels(2)
 .getItems().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

list(callbackopt) → {Deferred|*}

Executes current query and returns a result set based on the specified paging parameters.

The result is an instance of DataResultSet. The returned records may contain nested objects based on the definition of the current model (expandable fields). This operation is one of the common data operations on MOST Data Applications where the affected records may have nested objects which contain the associated objects of each object. 


 {
    "total": 242,
    "records": [
        ...
        {
            "id": 46,
            "orderDate": "2014-12-31 13:35:41.000+02:00",
            "orderedItem": {
                "id": 413,
                "additionalType": "Product",
                "category": "Storage and Networking Gear",
                "price": 647.13,
                "model": "FY8135",
                "releaseDate": "2015-01-15 18:07:42.000+02:00",
                "name": "LaCie Blade Runner",
                "dateCreated": "2015-11-23 14:53:04.927+02:00",
                "dateModified": "2015-11-23 14:53:04.934+02:00"
            },
            "orderNumber": "DEF193",
            "orderStatus": {
                "id": 7,
                "name": "Problem",
                "alternateName": "OrderProblem",
                "description": "Representing that there is a problem with the order."
            },
            "paymentDue": "2015-01-20 13:35:41.000+02:00",
            "paymentMethod": {
                "id": 7,
                "name": "PayPal",
                "alternateName": "PayPal",
                "description": "Payment via the PayPal payment service."
            },
            "additionalType": "Order",
            "description": null,
            "dateCreated": "2015-11-23 21:00:18.306+02:00",
            "dateModified": "2015-11-23 21:00:18.307+02:00"
        }
        ...
    ]
}
Parameters:
Name Type Attributes Description
callback function <optional>
 A callback function with arguments (err, result) where the first argument is the error, if any and the second argument is an object that represents a result set
Inherited From:
Source:
Returns:
- If callback is missing returns a promise.
Type
Deferred | *
Example
//retrieve products list order by price
 context.model('Product')
 .where('category').equal('LCDs and Peripherals')
 .orderByDescending('price')
 .take(3).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

lowerOrEqual(obj) → {DataQueryable}

Prepares a lower than or equal comparison.
Parameters:
Name Type Description
obj * The right operand of the expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve orders based on payment due date
 context.model('Order')
 .orderBy('paymentDue')
 .where('paymentDue').lowerOrEqual(moment().subtract('days',-7).toDate())
 .and('paymentDue').greaterThan(new Date())
 .take(10).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

lowerThan(obj) → {DataQueryable}

Prepares a lower than comparison
Parameters:
Name Type Description
obj *
Inherited From:
Source:
Returns:
Type
DataQueryable

max(attr, callbackopt) → {Deferred|*}

Executes the query against the current model and returns the maximum value of the given attribute.
Parameters:
Name Type Attributes Description
attr string A string that represents a field of the current model
callback function <optional>
 A callback function where the first argument will contain the Error object if an error occured, or null otherwise. The second argument will contain the result, if any.
Inherited From:
Source:
Returns:
- If callback parameter is missing then returns a Deferred object.
Type
Deferred | *
Example
//retrieve the maximum price of products sold during last month
 context.model('Order')
 .where('orderDate').greaterOrEqual(moment().startOf('month').toDate())
 .max('orderedItem/price').then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

migrate(callback)

Migrates the underlying data association adapter.
Parameters:
Name Type Description
callback A callback function where the first argument will contain the Error object if an error occured, or null otherwise.
Overrides:
Source:

min(attr, callbackopt) → {Deferred|*}

Executes the query against the current model and returns the average value of the given attribute.
Parameters:
Name Type Attributes Description
attr string A string that represents a field of the current model
callback function <optional>
 A callback function where the first argument will contain the Error object if an error occured, or null otherwise. The second argument will contain the result, if any.
Inherited From:
Source:
Returns:
- If callback parameter is missing then returns a Deferred object.
Type
Deferred | *
Example
//retrieve the mininum price of products sold during last month
 context.model('Order')
 .where('orderDate').greaterOrEqual(moment().startOf('month').toDate())
 .min('orderedItem/price').then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

mod(obj, result) → {DataQueryable}

Prepares a modular arithmetic operation
Parameters:
Name Type Description
obj * The value to be compared
result Number The result of modular expression
Inherited From:
Source:
Returns:
Type
DataQueryable

multiply(x) → {DataQueryable}

Prepares a multiplication (e.g. ([field] * 0.2))
Parameters:
Name Type Description
x number
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of orders
 context.model('Product')
 .select('id','name', 'price')
 //perform ((ProductData.price * 0.2)<50)
 .where('price').multiply(0.2).lowerThan(50)
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

notContains(value) → {DataQueryable}

Prepares a not contains comparison (e.g. a string contains another string).
Parameters:
Name Type Description
value * The right operand of the expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve persons where the given name not contains 'ar'
 context.model('Person').select(['id','givenName','familyName'])
 .where('givenName').notContains('ar')
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//The result set of this example may be:
 id   givenName  familyName
 ---  ---------  ----------
 257  Daisy      Lambert
 259  Peter      French
 261  Kylie      Jordan
 263  Maxwell    Hall
 265  Christian  Marshall

notEqual(obj) → {DataQueryable}

Prepares a not equal comparison.
Parameters:
Name Type Description
obj * The right operand of the expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of orders with order status different than 1
 context.model('Order')
 .where('orderStatus').notEqual(1)
 .orderByDescending('orderDate')
 .list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

notIn(objs) → {DataQueryable}

Prepares a typical NOT IN comparison.
Parameters:
Name Type Description
objs Array An array of values which represents the values to be used in expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve orders with order status 1 or 2
 context.model('Order').where('orderStatus').notIn([1,2])
 .list().then(function(result) {
        //WHERE (NOT OrderData.orderStatus IN (1, 2))
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

or(attr) → {DataQueryable}

Prepares a logical OR expression
Parameters:
Name Type Description
attr string The name of field that is going to be used in this expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//((OrderData.orderStatus=1) OR (OrderData.orderStatus=2)
 context.model('Order').where('orderStatus').equal(1)
 .or('orderStatus').equal(2)
 .list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

orderBy(attr) → {DataQueryable}

Prepares an ascending sorting operation
Parameters:
Name Type Description
attr string The field name to use for sorting results
Inherited From:
Source:
Returns:
Type
DataQueryable

orderByDescending(attr) → {DataQueryable}

Prepares a descending sorting operation
Parameters:
Name Type Description
attr string The field name to use for sorting results
Inherited From:
Source:
Returns:
Type
DataQueryable

prepare(useOropt) → {DataQueryable}

Serializes the underlying query and clears current filter expression for further filter processing. This operation may be used in complex filtering.
Parameters:
Name Type Attributes Description
useOr Boolean <optional>
 Indicates whether an or statement will be used in the resulted statement.
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of order
 context.model('Order')
 .where('orderStatus').equal(1).and('paymentMethod').equal(2)
 .prepare().where('orderStatus').equal(2).and('paymentMethod').equal(2)
 .prepare(true)
 //(((OrderData.orderStatus=1) AND (OrderData.paymentMethod=2)) OR ((OrderData.orderStatus=2) AND (OrderData.paymentMethod=2)))
 .list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

remove(obj, callbackopt)

Removes a value or an array of values
Parameters:
Name Type Attributes Description
obj Array | *
callback function <optional>
Source:
Example
context.model('Person').where('email').equal('veronica.fletcher@example.com')
 .getTypedItem().then(function(person) {
        person.property('skills').remove([
            "node.js"
        ]).then(function() {
            return done();
        });
    }).catch(function(err) {
        return done(err);
    });

removeAll(callbackopt)

Removes all values
Parameters:
Name Type Attributes Description
callback function <optional>
Source:
Example
context.model('Person').where('email').equal('veronica.fletcher@example.com')
 .getTypedItem().then(function(person) {
        person.property('skills').removeAll().then(function() {
            return done();
        });
    }).catch(function(err) {
        return done(err);
    });

round(nopt) → {DataQueryable}

* Prepares a round mathematical expression
Parameters:
Name Type Attributes Description
n number <optional>
Inherited From:
Source:
Returns:
Type
DataQueryable
Initializes a full-text search expression
Parameters:
Name Type Description
text string A string which represents the text we want to search for
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
context.model('Person')
 .search('Peter')
 .select('description')
 .take(25).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

select(…attr) → {DataQueryable}

Selects a field or a collection of fields of the current model.
Parameters:
Name Type Attributes Description
attr string <repeatable>
 An array of fields, a field or a view name
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve the last 5 orders
 context.model('Order').select('id','customer','orderDate','orderedItem')
 .orderBy('orderDate')
 .take(5).list().then(function(result) {
        console.table(result.records);
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
//retrieve the last 5 orders by getting the associated customer name and product name
 context.model('Order').select('id','customer/description as customerName','orderDate','orderedItem/name as productName')
 .orderBy('orderDate')
 .take(5).list().then(function(result) {
        console.table(result.records);
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//The result set of this example may be:
 id   customerName         orderDate                      orderedItemName
 ---  -------------------  -----------------------------  ----------------------------------------------------
 46   Nicole Armstrong     2014-12-31 13:35:41.000+02:00  LaCie Blade Runner
 288  Cheyenne Hudson      2015-01-01 13:24:21.000+02:00  Canon Pixma MG5420 Wireless Photo All-in-One Printer
 139  Christian Whitehead  2015-01-01 23:21:24.000+02:00  Olympus OM-D E-M1
 3    Katelyn Kelly        2015-01-02 04:42:58.000+02:00  Kobo Aura
 59   Cheyenne Hudson      2015-01-02 10:47:53.000+02:00  Google Nexus 7 (2013)

 
//retrieve the best customers by getting the associated customer name and a count of orders made by the customer
 context.model('Order').select('customer/description as customerName','count(id) as orderCount')
 .orderBy('count(id)')
 .groupBy('customer/description')
 .take(3).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//The result set of this example may be:
 customerName      orderCount
 ----------------  ----------
 Miranda Bird      19
 Alex Miles        16
 Isaiah Morton     16

silent(valueopt) → {DataQueryable}

Disables permission listeners and executes the underlying query without applying any permission filters
Parameters:
Name Type Attributes Description
value Boolean <optional>
 A boolean which represents the silent flag. If value is missing the default parameter is true.
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve user
 context.model('User')
 .where('name').equal('other@example.com')
 .silent()
 .first().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

skip(n) → {DataQueryable}

Prepares a paging operation by skipping the specified number of records
Parameters:
Name Type Description
n number The number of records to be skipped
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of products
 context.model('Product')
 .skip(10)
 .take(10)
 .list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

startsWith(obj) → {DataQueryable}

Prepares an ends with comparison
Parameters:
Name Type Description
obj * The string to be searched for at the end of a field.
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve people whose given name starts with 'D'
 context.model('Person')
 .where('givenName').startsWith('D')
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//Results:
 id   givenName  familyName
 ---  ---------  ----------
 257  Daisy      Lambert
 275  Dustin     Brooks
 333  Dakota     Gallagher

substr(start, lengthopt) → {DataQueryable}

Prepares a substring comparison
Parameters:
Name Type Attributes Description
start number The position where to start the extraction. First character is at index 0
length number <optional>
 The number of characters to extract
Inherited From:
Source:
Returns:
Type
DataQueryable
Examples
//retrieve a list of persons
 context.model('Person')
 .select('givenName')
 .where('givenName').substr(0,4).equal('Alex')
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });
 
//Results:
 givenName
 ---------
 Alex
 Alexis

subtract(x) → {DataQueryable}

Prepares a subtraction (e.g. ([field] - 4))
Parameters:
Name Type Description
x number | *
Inherited From:
Source:
Returns:
//retrieve a list of orders context.model('Product') .select('id','name', 'price') //perform ((ProductData.price - 50)<150) .where('price').subtract(50).lowerThan(150) .take(5).list().then(function(result) { done(null, result); }).catch(function(err) { done(err); });
Type
DataQueryable

sumOf(name, aliasopt) → {*|QueryField}

Parameters:
Name Type Attributes Description
name string
alias string <optional>
Inherited From:
Source:
Returns:
Type
* | QueryField

take(n, callbackopt) → {DataQueryable|*}

Prepares a data paging operation by taking the specified number of records
Parameters:
Name Type Attributes Description
n Number The number of records to take
callback function <optional>
 A callback function where the first argument will contain the Error object if an error occured, or null otherwise. The second argument will contain the result.
Inherited From:
Source:
Returns:
- If callback function is missing returns a promise.
Type
DataQueryable | *

thenBy(attr) → {DataQueryable}

Continues a ascending sorting operation
Parameters:
Name Type Description
attr string The field to use for sorting results
Inherited From:
Source:
Returns:
Type
DataQueryable

thenByDescending(attr) → {DataQueryable}

Continues a descending sorting operation
Parameters:
Name Type Description
attr string The field name to use for sorting results
Inherited From:
Source:
Returns:
Type
DataQueryable

title(valueopt) → {string|DataQueryable}

Gets or sets a string which represents the title of this DataQueryable instance. This title may be used in caching operations
Parameters:
Name Type Attributes Description
value string <optional>
 The title of this DataQueryable instance
Inherited From:
Source:
Returns:
Type
string | DataQueryable

toExpand(attr)

Converts a DataQueryable instance to an object which is going to be used as parameter in DataQueryable.expand() method
Parameters:
Name Type Description
attr String A string which represents the attribute of a model which is going to be expanded with the options specified in this instance of DataQueryable.
Inherited From:
Source:
Example
//get customer and customer orders with options (e.g. select specific attributes and sort orders by order date)
 context.model("Person")
 .search("Daisy")
 .expand(context.model("Order").select("id", "customer","orderStatus", "orderDate", "orderedItem").levels(2).orderByDescending("orderDate").take(10).toExpand("orders"))
 .take(3)
 .getItems()
 .then(function (result) {
        console.log(JSON.stringify(result));
        done();
    }).catch(function (err) {
    done(err);
});

toLocaleLowerCase() → {DataQueryable}

Prepares a lower case string comparison
Inherited From:
Source:
Returns:
Type
DataQueryable

toLocaleUpperCase() → {DataQueryable}

Prepares an upper case string comparison
Inherited From:
Source:
Returns:
Type
DataQueryable

toLowerCase() → {DataQueryable}

Prepares a lower case string comparison
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
//retrieve a list of persons
 context.model('Person')
 .where('givenName').toLocaleLowerCase().equal('alexis')
 .take(5).list().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

toMD5() → {string}

Generates a MD5 hashed string for this DataQueryable instance
Inherited From:
Source:
Returns:
Type
string

toUpperCase() → {DataQueryable}

Prepares an upper case string comparison
Inherited From:
Source:
Returns:
Type
DataQueryable

trim() → {DataQueryable}

Prepares a string trimming expression
Inherited From:
Source:
Returns:
Type
DataQueryable

value(callbackopt) → {Deferred|*}

Executes the underlying query and a single value.
Parameters:
Name Type Attributes Description
callback function <optional>
 A callback function where the first argument will contain the Error object if an error occured, or null otherwise. The second argument will contain the result.
Inherited From:
Source:
Returns:
Type
Deferred | *
Example
//retrieve the full name (description) of a person
 context.model('Person')
 .where('user').equal(330)
 .select('description')
 .value().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });

where(attr) → {DataQueryable}

Initializes a where expression
Parameters:
Name Type Description
attr string A string which represents the field name that is going to be used as the left operand of this expression
Inherited From:
Source:
Returns:
Type
DataQueryable
Example
context.model('Person')
 .where('user/name').equal('user1@exampl.com')
 .select('description')
 .first().then(function(result) {
        done(null, result);
    }).catch(function(err) {
        done(err);
    });