When dates are stored in milliseconds, such as 1126483200000, they represent the time elapsed since January 1, 1970, 00:00:00 GMT, according to Oracle’s system. This format translates each second into a thousand milliseconds, resulting in a figure that is cumbersome and challenging to interpret due to its magnitude. Consequently, to make sense of these extensive numbers, a conversion to a more readable date string format is often necessary.
Solution:
To address this issue, the following SQL query can be employed:
```sql
select to_char(to_date('1970-01-01 00','yyyy-mm-dd hh24') +
(1126483200000)/1000/60/60/24, 'YYYY-MM-DD HH12:MI:SS am') datestr from dual;
```This query is designed to transform the millisecond value of 1126483200000 into a human-friendly date format, specifically ‘YYYY-MM-DD HH12:MI:SS am’. Upon execution, it presents the date as September 12, 2005, 12:00:00 AM. It offers the flexibility to modify the millisecond input to any desired value by referencing the start date of January 1, 1970, at 00:00 hours.
For individuals requiring a different format, specifically one that displays time in a 24-hour notation, an adjustment to the pattern within the query can easily accommodate this preference. The example below illustrates how to achieve a 24-hour time format:
```sql
select to_char(to_date('1970-01-01 00','yyyy-mm-dd hh24') +
(1126483200000)/1000/60/60/24, 'HH24:MI:SS') datestr from dual;
```This variation of the query continues to leverage the initial millisecond value, converting it into a concise ‘HH24:MI:SS’ time format. Through these SQL statements, the conversion of milliseconds into a readable date or time format becomes a straightforward process, enabling clearer data interpretation and utilization within Oracle databases.
To Wrap Up
In conclusion, converting milliseconds to a readable date string in Oracle SQL is a powerful technique for simplifying database date handling. By leveraging SQL queries, we can transform cumbersome millisecond values into human-friendly date formats, such as ‘YYYY-MM-DD HH12:MI:SS am’ or ‘HH24:MI:SS’. This conversion process not only aids in making data interpretation more accessible but also enhances the usability of temporal data stored in Oracle databases. Whether the requirement is to display dates in a 12-hour or 24-hour notation, the flexibility of the provided SQL queries ensures that users can tailor the output to meet their specific needs. Overall, understanding and applying these conversion techniques is invaluable for anyone working with time-based data in Oracle SQL, facilitating more efficient and effective data management practices.