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日付と時刻の関数

TIMEDIFF

Calculates the difference between two date, time, or timestamp expressions based on the specified date or time part. The function returns the result of subtracting the second argument from the third argument.

DATEDIFF の代替です。

構文

TIMEDIFF( <date_or_time_part> , <date_or_time_expr1> , <date_or time_expr2> )

引数

date_or_time_part

The unit of time. Must be one of the values listed in サポートされている日付と時刻の部分 (e.g. month). The value can be a string literal or can be unquoted (e.g. 'month' or month).

date_or_time_expr1, date_or_time_expr2

The values to compare. Must be a date, a time, a timestamp, or an expression that can be evaluated to a date, a time, or a timestamp. The value date_or_time_expr1 is subtracted from date_or_time_expr2.

Returns

Returns an integer representing the number of units (seconds, days, etc.) difference between date_or_time_expr2 and date_or_time_expr1.

使用上の注意

  • Output values can be negative, for example, -12 days.

  • date_or_time_expr1 and date_or_time_expr2 can be a date, time, or timestamp.

  • The function supports units of years, quarters, months, weeks, days, hours, minutes, seconds, milliseconds, microseconds, and nanoseconds.

  • date_or_time_part は、 サポートされている日付と時刻の部分 にリストされている値のいずれかでなければなりません。

    If date_or_time_part is week (or any of its variations), the output is controlled by the WEEK_START session parameter. For more details, including examples, see カレンダーの週と平日.

  • The unit (e.g. month) used to calculate the difference determines which parts of the DATE, TIME, or TIMESTAMP field are used to determine the result and thus determines the precision of the result.

    Smaller units are not used, so values are not rounded. For example, even though the difference between January 1, 2021 and February 28, 2021 is closer to two months than to one month, the following returns one month:

    DATEDIFF(month, '2021-01-01'::DATE, '2021-02-28'::DATE)
    

    For a DATE value:

    • year uses only the year and disregards all the other parts.

    • month uses the month and year.

    • day uses the entire date.

    For a TIME value:

    • hour uses only the hour and disregards all the other parts.

    • minute uses the hour and minute.

    • second uses the hour, minute, and second, but not the fractional seconds.

    • millisecond uses the hour, minute, second, and first three digits of the fractional seconds. Fractional seconds are not rounded. For example, DATEDIFF(milliseconds, '00:00:00', '00:00:01.1239') returns 1.123 seconds, not 1.124 seconds.

    • microsecond uses the hour, minute, second, and first six digits of the fractional seconds. Fractional seconds are not rounded.

    • nanosecond uses the hour, minute, second, and all nine digits of the fractional seconds.

    For a TIMESTAMP value:

    The rules match the rules for DATE and TIME data types above. Only the specified unit and larger units are used.

これは、2つの日付を減算した結果を示しており、2番目の日付は最初の日付から2年後のものです。

SELECT TIMEDIFF(YEAR, '2017-01-01', '2019-01-01') AS Years;
+-------+
| YEARS |
|-------|
|     2 |
+-------+

これは、値が丸められるのではなく切り捨てられることを示しています。差は11か月よりも12か月に近いですが、Snowflakeは差を11か月として計算します。

SELECT TIMEDIFF(MONTH, '2017-01-1', '2017-12-31') AS Months;
+--------+
| MONTHS |
|--------|
|     11 |
+--------+

DATEDIFF には追加の例があります。

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