Cast

2005
2008
2012
2014
2016
2017
2019
2022

2005, 2008, 2012, 2014, 2016, 2017, 2019, 2022

Cast Conversion Function

Use the Cast function to change the database type of an expression to a different database type.

Syntax

db.fx.Cast({expression}).{data_type_method}([{length}])

Arguments

expression: – The field expression, composite element, or function result to use in calculating the population variance.

data_type_method: – The method specifying the database type the `expression` should be cast to.

length: – For cast operations to database types supporting a 'length' (`varchar`, `char`, `nvarchar`, `nchar`), the length of the database type returned from the cast operation.

Returns

data_type_method	return type (based on nullability of expression)
`AsBit()`	`bool` or `bool?`
`AsSmallInt()`	`byte` or `byte?`
`AsInt()`	`int` or `int?`
`AsBigInt()`	`long` or `long?`
`AsDecimal()`	`decimal` or `decimal?`
`AsFloat()`	`float` or `float?`
`AsDateTime()`	`DateTime` or `DateTime?`
`AsDateTimeOffset()`	`DateTimeOffset` or `DateTimeOffset?`
`AsUniqueIdentifier()`	`Guid` or `Guid?`
`AsVarChar({length})`	`string` or `string?`
`AsChar({length})`	`string` or `string?`
`AsNVarChar({length})`	`string` or `string?`
`AsNChar({length})`	`string` or `string?`
`AsTinyInt()`	`short` or `short?`
`AsTime()`	`TimeSpan` or `TimeSpan?`
`AsMoney()`	`double` or `double?`
`AsMoney()`	`double` or `double?`

Examples

Select Statement

Select the cast of total purchase amount to a varchar(20).

string? result = db.SelectOne(
        db.fx.Cast(dbo.Purchase.TotalPurchaseAmount).AsVarChar(20)
    )
    .From(dbo.Purchase)
    .Execute();

Order By Clause

Select the cast of zip code to an integer.

int cast = db.SelectOne(
        db.fx.Cast(dbo.Address.Zip).AsInt()
    )
    .From(dbo.Address)
    .OrderBy(db.fx.Cast(dbo.Address.Zip).AsInt().Desc())
    .Execute();

Group By Clause

Select the cast of all product quantities, grouped by product category type and cast of product quantity.

IEnumerable<dynamic> values = db.SelectMany(
        dbo.Product.ProductCategoryType,
        db.fx.Cast(dbo.Product.Quantity).AsBigInt().As("Quantity")
    )
    .From(dbo.Product)
    .GroupBy(
        dbo.Product.ProductCategoryType,
        db.fx.Cast(dbo.Product.Quantity).AsBigInt()
    )
    .Execute();

Having Clause

Select the cast of all product quantities, grouped by product category type and cast of product quantity having n casted value less than or equal to 1,000,000.

IEnumerable<dynamic> values = db.SelectMany(
        dbo.Product.ProductCategoryType,
        db.fx.Cast(dbo.Product.Quantity).AsBigInt().As("Quantity")
    )
    .From(dbo.Product)
    .GroupBy(
        dbo.Product.ProductCategoryType,
        dbo.Product.Quantity
    )
    .Having(db.fx.Cast(dbo.Product.Quantity).AsBigInt() <= 1_000_000)
    .Execute();