In Oracle, the data type used to store date and time values is called DATE. The DATE data type allows you to store dates ranging from January 1, 4712 BC to December 31, 9999 AD. It also includes a time component, allowing you to store values with precision up to seconds.
Date and Time Format
When working with the DATE data type in Oracle, it’s important to understand the default date and time format. By default, dates are displayed in the format DD-MON-YY HH:MI:SS, where:
- DD represents the day of the month (01-31)
- MON represents the abbreviated month name (Jan-Dec)
- YY represents the last two digits of the year (00-99)
- HH represents the hour in a 24-hour format (00-23)
- MI represents the minutes (00-59)
- SS represents the seconds (00-59)
The default date and time format can be altered using various formatting functions available in Oracle.
Date and Time Functions
In addition to storing and displaying date and time values, Oracle provides a rich set of built-in functions for manipulating them. Here are some commonly used date and time functions:
SysDate Function:
The SysDate() function is used to retrieve the current system date and time from your Oracle database. This function returns a value of the DATE data type.
Trunc Function:
The Trunc() function is used to remove the time component from a date value. It allows you to extract only the date portion, effectively setting the time to 00:00:00.
AddMonths Function:
The AddMonths() function allows you to add or subtract a specified number of months from a given date. This function is especially useful when performing calculations involving date intervals.
Date and Time Operations
Oracle supports various operations on date and time values, allowing you to perform calculations, comparisons, and formatting. Some commonly used operations include:
- Arithmetic Operations: You can perform arithmetic operations such as addition and subtraction on date and time values. For example, you can add or subtract days using the + and – operators.
- Date Comparisons: You can compare dates using comparison operators like =, >, <, >=, and <=. These comparisons are performed based on the underlying numeric representation of dates in Oracle.
- Date Formatting: Oracle provides various formatting functions like TO_CHAR() that allow you to format dates according to your requirements. These functions enable you to display dates in different formats such as DD/MM/YYYY or MM/DD/YYYY.
Conclusion
In Oracle, the DATE data type is used for storing date and time values. It provides a wide range of functions for manipulating and working with these values. By understanding the default format, commonly used functions, and available operations, you can effectively handle date and time data in your Oracle database.