How can Oracle modify data of date type?

To update DATE type data in an Oracle database, you can use the UPDATE statement for the operation. Here is an example:

UPDATE 表名
SET 列名 = TO_DATE('新日期', '日期格式')
WHERE 条件;

In this case, “table name” is the name of the table to be modified, “column name” is the name of the column to be modified, “new date” is the new date value to be updated, “date format” is the format of the new date value, and “condition” is an optional item used to specify the rows to be updated.

For example, to change the value of the “hire_date” column in the table “employees” to “2022-01-01”, you can execute the following statement:

UPDATE employees
SET hire_date = TO_DATE('2022-01-01', 'YYYY-MM-DD')
WHERE employee_id = 1001;

This will change the hire date of the employee with employee_id 1001 to January 1st, 2022.

Please note that DATE data in Oracle is stored in a specific format, so the TO_DATE function should be used to convert the new date to the specified format during an update operation.

Furthermore, other date functions and operators can be used to modify and calculate DATE type data, such as adding months with the ADD_MONTHS function, extracting date parts with the EXTRACT function, etc.