Converts the given expression to character form and returns the result. The primary use for TO_CHAR is to format the output of date-time expressions through the format_string argument.
Syntax
TO_CHAR ( expresion[ , format_string] )
Parameters
expression
Converts to character form. It must evaluate to a value of the date or time data type to use the format_string.
format_string
Specifies the format of the output. SQL ignores the format string if the expression argument does not evaluate to a date or time.
Notes
The first argument to the function can be of any type.
The second argument, if specified, must be of type CHARACTER.
The result is of type CHARACTER.
The format argument can be used only when the type of the first argument is DATE.
If any of the argument expressions evaluates to NULL, the result is NULL.
The first argument to the function can be of any type.