interval usage in oracle

The INTERVAL type in Oracle is used to represent a time period, including time units (such as days, hours) and time quantities (such as 3, 10); it is often used to calculate the difference between date or time values. The syntax is INTERVAL time_value time_unit, where time_value is the time quantity and time_unit is the time unit, such as YEAR, MONTH, DAY, etc.; for example, calculate the number of days between two dates: SELECT INTERVAL '2023-06-15' - '2023-05 -15' DAY FROM DUAL;

INTERVAL type in Oracle

INTERVAL type is used to represent a time period or Date range. It contains the following two parts:

• Time unit (for example, days, hours, minutes)
• Time quantity (for example, 3, 10, 50)

Usage

INTERVAL type is generally used to calculate the difference between date or time values. The syntax is as follows:

<code>INTERVAL time_value time_unit</code>

Where:

• time_value is the time quantity, which can be a positive or negative number.

• time_unit is the time unit and can be the following values:

  • YEAR
  • MONTH
  • ##DAY
  • HOUR
  • MINUTE
  • SECOND

Example

<code>-- 计算两个日期之间的天数
SELECT INTERVAL '2023-06-15' - '2023-05-15' DAY FROM DUAL;</code>

<code>31</code>

<code>-- 计算当前时间到指定时间的分钟数
SELECT INTERVAL TIMESTAMP '2023-06-15 10:30:00' - CURRENT_TIMESTAMP MINUTE FROM DUAL;</code>

<code>25</code>

<code>-- 根据天数创建一个 INTERVAL
SELECT INTERVAL 30 DAY FROM DUAL;</code>

<code>30 DAY</code>

Notes

INTERVAL type cannot be directly used with Date or time values ​​are compared.
• The precision of the INTERVAL type depends on the time unit. For example, 1 DAY is more precise than 1 HOUR.
• When using the INTERVAL type, ensure that the time unit matches the calculated difference.

The above is the detailed content of interval usage in oracle. For more information, please follow other related articles on the PHP Chinese website!