SQL Server CAST() Function

Convert a value to an int datatype:

SELECT CAST(25.65 AS int);

Definition and Usage

The CAST() function converts a value (of any type) into a specified datatype.

Tip: Also look at the CONVERT() function.

CAST(expression AS datatype(length))

Value	Description
expression	Required. The value to convert
datatype	Required. The datatype to convert expression to. Can be one of the following: bigint, int, smallint, tinyint, bit, decimal, numeric, money, smallmoney, float, real, datetime, smalldatetime, char, varchar, text, nchar, nvarchar, ntext, binary, varbinary, or image
(length)	Optional. The length of the resulting data type (for char, varchar, nchar, nvarchar, binary and varbinary)

Works in:	SQL Server (starting with 2008), Azure SQL Database, Azure SQL Data Warehouse, Parallel Data Warehouse

Convert a value to a varchar datatype:

SELECT CAST(25.65 AS varchar);

Convert a value to a datetime datatype:

SELECT CAST('2017-08-25' AS datetime);