What are the functions of the CAST function in SQL?

In SQL, the CAST function is used to convert one data type to another data type. Its purpose includes:

1. Type conversion: the process of converting one data type into another. For example, converting a string into a number, or converting a date into a string.
2. Format data: Formatting data according to a specified format, such as converting numbers to currency format or dates to a specific date format.
3. Data truncation: cutting data to a specified length or precision. For example, taking only the first few characters of a string, or trimming a decimal to a specified number of digits.
4. Data rounding: rounding data to a specified number of decimal places, such as rounding decimals to integers or rounding decimals to a specified number of decimal places.
5. Data conversion involves converting one data type to another data type, while also formatting, truncating, or rounding. For example, converting a date to a string and truncating the year.