TOSTRING takes a date value and creates a representation of it as a string. The optional format specification parameter defines the structure of the string to create. For example, if the date information is 1998-APR-02, you can format the resulting string as April 2, 1998.
Use any combination in your format (except those that return the number of a day or week within a year for a given date). For example, TOSTRING (1998-APR-02, ‘MONTH DD, YY’) returns the value APRIL 02, 98.
If you use a relational database management system, your data store may not be able to use its native (built-in) functions to execute the request. If so, the program performs the conversion, which can take more time than if the data store did the conversion.
TODATE takes a string value representing a date or time and converts it to a date object. The optional format specification parameter defines the format used to represent the date in the string. For example, for a string containing the date April 2, 1998 ,the format specification should contain Month DD, YYYY. The following table outlines the formatting options available:
|YY||Defines the year as a two-digit number, for example, 07.|
|YYYY||Defines the year as a four-digit number, for example, 2007.|
|MONTH||Defines the month using its name in uppercase letters, for example, APRIL.|
|month||Defines the month using its name in lowercase letters, for example, april.|
|Month||Defines the month using its name with an initial capital letter, for example, April.|
|MON||Defines the month using its three-letter abbreviation in uppercase, for example, APR.|
|mon||Defines the month using its three-letter abbreviation in lowercase, for example, apr.|
|MM||Defines the month using its two-number abbreviation, for example, 04.|
|DAY||Defines the day using its name in uppercase letters, for example, FRIDAY.|
|day||Defines the day using its name in lowercase letters, for example, friday.|
|Day||Defines the day using its name with an initial capital letter, for example, Friday.|
|DY||Defines the day using its abbreviation in uppercase, for example, FRI.|
|dy||Defines the day using its abbreviation in lowercase, for example, fri.|
|DD||Defines the day using its two-number abbreviation, for example, 06.|
|hh24||Defines an hour using its number in the range [0-24].|
|hh12||Defines an hour using its number in the range [0-12].|
|hh||Defines an hour using its number in the default representation (by default, hh24).|
|am|pm||Uses the ante-meridiem (morning) and post-meridiem (after noon) specification. |
Noon is often called 12:00 p.m. and midnight 12:00 a.m., as at the beginning of a day.
This format is considered only when used with the time range [1-12] (format hh12).