DATEPART
-Returns an integer representing the specified datepart of the specified date.

Используй CONVERT (data_type[(length)], expression [, style])


where style

Is the style of date format you want when converting datetime or smalldatetime data to character data ( nchar, nvarchar, char, varchar, nchar, or nvarchar data types ), ....
In the table, the two columns on the left represent the style values for datetime or smalldatetime conversion to character data. Add 100 to a style value to get a four-place year that includes the century (yyyy).

Успехов