Class Day

Namespace

YndigoBlue.Velocity.Functions

Assembly

YndigoBlue.Velocity.dll

Represents the DAY date extraction function that returns the day of the month component of a date.

public class Day : Function, ICheckItem, IDefaultItem, IFilterItem, IElement

Inheritance

object

Function

Day

Implements

ICheckItem

IDefaultItem

IFilterItem

IElement

Remarks

The DAY function extracts the day of the month as an integer (1-31) from a date or datetime value. For example, DAY('2024-03-15') returns 15. This is useful for filtering by specific days of the month, day-based analysis, or extracting the day component for calculations.

Examples

Extract the day-of-month from each invoice date:

var schema = manager.LoadSchema("finance");
var invoices = schema["invoices"];

var query = new Query()
    .Select([ invoices["id"], new Expression("invoice_day", new Day(invoices["invoice_date"])) ])
    .From(invoices);

var results = manager.Retrieve(query);

Use the typed Column constructor when working with a pre-resolved column variable:

var schema = manager.LoadSchema("finance");
var invoices = schema["invoices"];
Column invoiceDateColumn = invoices["invoice_date"];

var query = new Query()
    .Select([ invoices["id"], new Expression("invoice_day", new Day(invoiceDateColumn)) ])
    .From(invoices);

var results = manager.Retrieve(query);

Extract the day from a hard-coded date literal using DateOnly or DateTimeOffset:

// DateOnly literal: DAY('2024-03-15') → 15
var dayFromDateOnly = new Day(new DateOnly(2024, 3, 15));

// DateTimeOffset literal
var dayFromOffset = new Day(new DateTimeOffset(2024, 3, 15, 0, 0, 0, TimeSpan.Zero));

Constructors

Day(IEnumerable<IElement>)

Initializes a new instance of DAY for multiple elements.

Day(DateOnly)

Initializes a new instance of DAY for a DateOnly literal value.

Day(DateTime)

Initializes a new instance of DAY for a DateTime literal value.

Day(DateTimeOffset)

Initializes a new instance of DAY for a DateTimeOffset literal value.

Day(IElement)

Initializes a new instance of DAY for a single element.

Day(Column)

Initializes a new instance of DAY for a column.