Oracle when row function date, oracle when row

Oracle when row function date, oracle when row

Date of use

 

Oracle internal use of digital storage date: century, year, month, day, hour, minute, second.

The default date display format is DD-MON-RR.

-- Only the last two digits of a year can be specified, and the 21st century date can be stored in the 21st century.
-- Similarly, the 20th century date can be stored in the 21st century.

 

SELECT last_name, hire_date
FROM employees
WHERE hire_date <'01-FEB-88 ';

 

SELECT last_name, (SYSDATE-hire_date)/7 AS WEEKS
FROM employees
WHERE department_id = 90;

 

 

How can I query the time when a field in the table is changed in the oracle database? Thank you!

Unable to query this information

If you want to implement it by yourself, you can use a trigger:

For example, modify record rows: Add alterdate and trigger. When the row is modified, update the alterdate column.

For example, modify a record column: Add a table (data column modification record, if the column is modified, record the modified table, column, pre-modification value, and modified value)

How can I insert data into a specified row in ORACLE?

Update A2
Set A2. time = (
Select sum (A1. time)
From A1
Where A1. unit = A2. Unit
Group by A1.
)