Example 1: mysql date diff
SELECT DATEDIFF(expr1,expr2) as difference_in_days;
select DATEDIFF('2020-05-15', '2020-05-10');
select DATEDIFF('2020-05-13', '2020-05-16');
select DATEDIFF('2020-06-30', '2020-05-30');
Example 2: sql select between two dates
select Date, TotalAllowance from Calculation where EmployeeId = 1
and Date between '2011/02/25' and '2011/02/27'
Example 3: date difference in number of days sql server
DECLARE
@start_dt DATETIME2= '2019-12-31 23:59:59.9999999',
@end_dt DATETIME2= '2020-01-01 00:00:00.0000000';
SELECT
DATEDIFF(year, @start_dt, @end_dt) diff_in_year,
DATEDIFF(quarter, @start_dt, @end_dt) diff_in_quarter,
DATEDIFF(month, @start_dt, @end_dt) diff_in_month,
DATEDIFF(dayofyear, @start_dt, @end_dt) diff_in_dayofyear,
DATEDIFF(day, @start_dt, @end_dt) diff_in_day,
DATEDIFF(week, @start_dt, @end_dt) diff_in_week,
DATEDIFF(hour, @start_dt, @end_dt) diff_in_hour,
DATEDIFF(minute, @start_dt, @end_dt) diff_in_minute,
DATEDIFF(second, @start_dt, @end_dt) diff_in_second,
DATEDIFF(millisecond, @start_dt, @end_dt) diff_in_millisecond;
Example 4: find difference in dates sql
SELECT DATEDIFF(day, date1,date2) AS DateDiff
Example 5: postgresql get difference between two dates
select age('2010-04-01', '2012-03-05'),
date_part('year',age('2010-04-01', '2012-03-05')),
date_part('month',age('2010-04-01', '2012-03-05')),
date_part('day',age('2010-04-01', '2012-03-05'));
Example 6: difference in dates sql
SELECT (END_DATE - START_DATE) Days-Total FROM MyTable