加一小时
select to_char(sysdate,'MM/DD/YYYY HH:MI:SS'),
to_char(sysdate + 1/24,'MM/DD/YYYY HH:MI:SS'),
systimestamp,
systimestamp + numtodsinterval(1,'hour')
from dual
少一块，重新生成一个吧
加一天
select sysdate + 1 as add_day,
systimestamp + numtodsinterval(1, 'day')
from dual
加一周
select sysdate + 7 as add_day,
systimestamp + numtodsinterval(7, 'day')
from dual
加一月
select add_months(sysdate, 1) add_month,
cast(add_months(systimestamp,1) as timestamp with time zone)
from dual
加一年
select add_months(sysdate, 12) add_month,
cast(add_months(systimestamp,12) as timestamp with time zone)
from dual
使用 TO_CHAR 格式化日期和数字
iw 格式表示一年中的第几周，iyyy 格式表示基于 ISO 标准的 4 位年份。
WITH dates AS (
SELECT date'2015-01-01' d FROM dual union
SELECT date'2015-01-10' d FROM dual union
SELECT date'2015-02-01' d FROM dual
)
SELECT d "Original Date",
to_char(d, 'dd-mm-yyyy') "Day-Month-Year",
to_char(d, 'hh24:mi') "Time in 24-hr format",
to_char(d, 'iw-iyyy') "ISO Year and Week of Year"
FROM dates
此语句将日期和时间戳值转换为 TO_CHAR 函数中指定的格式。
WITH dates AS (
SELECT date'2015-01-01' d FROM dual union
SELECT date'2015-01-10' d FROM dual union
SELECT date'2015-02-01' d FROM dual union
SELECT timestamp'2015-03-03 23:44:32' d FROM dual union
SELECT timestamp'2015-04-11 12:34:56' d FROM dual
)
SELECT d "Original Date",
to_char(d, 'dd-mm-yyyy') "Day-Month-Year",
to_char(d, 'hh24:mi') "Time in 24-hr format",
to_char(d, 'iw-iyyy') "ISO Year and Week of Year",
to_char(d, 'Month') "Month Name",
to_char(d, 'Year') "Year"
FROM dates
此语句从输入日期时间表达式中提取 EXTRACT 函数中指定的日期时间字段
WITH dates AS (
SELECT date'2015-01-01' d FROM dual union
SELECT date'2015-01-10' d FROM dual union
SELECT date'2015-02-01' d FROM dual union
SELECT timestamp'2015-03-03 23:44:32' d FROM dual union
SELECT timestamp'2015-04-11 12:34:56' d FROM dual
)
SELECT extract(minute from d) minutes,
extract(hour from d) hours,
extract(day from d) days,
extract(month from d) months,
extract(year from d) years
FROM dates
WITH nums AS (
SELECT 10 n FROM dual union
SELECT 9.99 n FROM dual union
SELECT 1000000 n FROM dual --one million
)
SELECT n "Input Number N",
to_char(n),
to_char(n, '9,999,999.99') "Number with Commas",
to_char(n, '0,000,000.000') "Zero-padded Number",
to_char(n, '9.9EEEE') "Scientific Notation"
FROM nums
'X' 格式返回指定位数的十六进制值。如果指定的数字不是整数，则将其四舍五入到最接近的整数
WITH nums AS (
SELECT 10 n FROM dual union
SELECT 9.99 n FROM dual union
SELECT .99 n FROM dual union
SELECT 1000000 n FROM dual --one million
)
SELECT n "号码",
to_char(n),
to_char(n, '9,999,999.99') "带逗号的数字",
to_char(n, '0,000,000.000') "补零数",
to_char(n, '9.9EEEE') "科学计数法",
to_char(n, '$9,999,990.00') 货币,
to_char(n, 'X') "十六进制值"
FROM nums
WITH nums AS (
SELECT 10 n FROM dual union
SELECT 9.99 n FROM dual union
SELECT .99 n FROM dual union
SELECT 1000000 n FROM dual --one million
)
SELECT n "Input Number N",
to_char(n),
to_char(n, '9,999,999.99') "Number with Commas",
to_char(n, '0,000,000.000') "Zero_padded Number",
to_char(n, '9.9EEEE') "Scientific Notation",
to_char(n, '$9,999,990.00') Monetary,
to_char(n, 'XXXXXX') "Hexadecimal Value"
FROM nums
