test=# select extract (month from timestamp '2017-07-31 22:18:00'); date_part 7 (1 row) test=# select extract (month from interval '2 years 11 months'); date_part 11 (1 row) 7. week (返回当前是几年的第几个周) test=# select extract (week from timestamp '2017-07-31 22:18...
获取当前时间戳: SELECT NOW(); 复制代码 获取时间戳的年、月、日等部分: SELECT EXTRACT(YEAR FROM timestamp) AS year, EXTRACT(MONTH FROM timestamp) AS month, EXTRACT(DAY FROM timestamp) AS day FROM table_name; 复制代码 将时间戳格式化为特定的字符串: SELECT TO_CHAR(timestamp, 'YYYY-MM...
selectfrom current_timestamp) from selectMONTH from current_timestamp) from selectDAY from current_timestamp) from selectHOUR from current_timestamp) from selectMINUTE from current_timestamp) from selectSECOND from current_timestamp) from 1. 2. 3. 4. 5. 6. 2.5 LAST_DAY(a_date DATE): 返...
month对于 timestamp 数值，它是一年里的月份数(1 - 12)； 对于 interval 数值，它是月的数目，然后对 12 取模(0 - 11)SELECT EXTRACT(MONTH from TIMESTAMP '2001-02-16 20:38:40');Result: 2SELECT EXTRACT(MONTH from INTERVAL '2 years 3 months');Result: 3SELECT EXTRACT(MONTH from...
testdb=# select extract(day from timestamp '2018-08-15 12:10:10'); date_part --- 15 (1 row) 例子:使用extract函数从日期中提取月份,如: testdb=# select extract(month from timestamp '2018-08-15 12:10:10'); date_part --- 8 (1...
3. extract(type from date) extract函数从日期中提取部分值。 (1)依次提取日期中的年份、月份、日部分 test=#selectextract(yearfromtimestamp'2017-05-31 21:31:20')asyear,extract(monthfromtimestamp'2017-05-31 21:31:20')asmonth,extract(dayfromtimestamp'2017-05-31 21:31:20')asday;year|month...
-- unix时间戳一般是10位,如果遇到13位的情况需要除1000; -- 末尾+1表示多1秒,例如1681574401为2023-04-16 00:00:02,也就是说两个unix时间的差值数字,表示差的秒数 select to_timestamp(1681574401); 时间戳 转 unix时间 select extract(epoch from '2023-04-16 00:00:01'::timestamp); 2.2.时间戳和...
SELECT make_time(1, 2, 30.5); make_time| ---| 01:02:30.5| make_timestamp(year int, month int, day int, hour int, min int, sec double precision) 函数通过指定年、月、日、时、分、秒创建一个时间戳。 SELECT make_timestamp(2020, 3, 15, 8, 20, 23.5); make_timestamp | -...
SELECT extract(year from current_date); -- 提取年份 SELECT extract(month from current_date); -- 提取月份 复制代码 使用to_timestamp函数将字符串转换为日期类型: SELECT to_timestamp('2021-10-05', 'YYYY-MM-DD'); -- 将字符串转换为日期类型 复制代码 通过以上方法,可以实现日期的加减运算和其他...
extract ( field from interval ) → double precision 获取时间间隔子字段 extract(month from interval '2 years 3 months')→ 3 isfinite ( date ) → boolean 测试有限日期(不是+/-无限) isfinite(date '2001-02-16')→ true isfinite ( timestamp ) → boolean 测试有限时间戳(不是+/-无限) isfi...