date-arithmetic

问题 How can I subtract a number of months from a date, to produce a different date? var date_A = 24-06-2016 var date_B = 24-01-2016 var x = 5 Please how can I use the value in x (number of months) to calculate the value for date_B, from the value date_A? 回答1: You can use the add_months() function: select add_months(to_date('24-06-2016', 'DD-MM-YYYY'), -5) from dual; ADD_MONTHS(TO_DATE('24-06-2016','DD-MM-YYYY'),-6) ------------------------------------------------- 2015-12-24 With SQL*Plus or SQL

问题 I have a question on how to split a file's data into multiple arrays and perform calculations on certain arrays. In my case, I need to read a hurricanes file and print out the name, year, category, pressure and windspeed each in its own array and then find the average of the category, pressure, and windspeed and then find out the number of a specific category, like Category 1: 26. I don't know how to do this. I used in.nextInt() but I assume it would print out all the numbers in the line of

问题 I am using code position calculation. So how could I show the output the result in the terminal? #include <ros/ros.h> #include <std_msgs/Float32MultiArray.h> #include <opencv2/opencv.hpp> #include <QTransform> #include <geometry_msgs/Point.h> #include <std_msgs/Int16.h> #include <find_object_2d/PointObjects.h> #include <find_object_2d/Point_id.h> #define dZ0 450 #define alfa 40 #define h 310 #define d 50 #define PI 3.14159265 void objectsDetectedCallback(const std_msgs::Float32MultiArray& msg

问题 In Oracle, you can use ADD_Months to add months on the fly in the sql statement. What is the MS SQL version. Oracle Example Select TestDate, TestFrequency, ADD_MONTHS(TestDate, TestFrequency) AS FutureTestDate FROM Tests Source : java's website 回答1: Its DATEADD(MONTH, TestFrequency, TestDate) to add TestFrequency number of months to the date field TestDate . 回答2: SQL Server's TSQL equivalent to Oracle's PLSQL ADD_MONTHS function is DATEADD: SELECT TestDate, TestFrequency, DATEADD(mm,

问题 I have devised the following code; to calculate the waiting time and expected time for a patient. The code should also echo a warning if the patient has been waiting too long. Please note: Waiting_time is DATETIME in the database. Here is the code; <?php $conn = mysqli_connect("localhost","root","") or die ("No connection"); mysqli_select_db($conn, "a&e") or die('Could not select database.'); $query = "SELECT PatientID, Forename, Surname, Gender, Illness, Priority, Arrival_time,NOW() as now

问题 I'm having issues with what I assumed would be a simple problem, but googling isn't helping a great load. Possibly I'm bad at what I am searching for nether the less. SELECT ORDER_NUMB, CUSTOMER_NUMB, ORDER_DATE FROM ORDERS WHERE FORMAT(ORDER_DATE, 'DD-MMM-YYYY') = '07-JUN-2000'; It tells me I am using an invalid identifier. I have tried using MON instead of MMM , but that doesn't help either. Unsure if it makes any difference but I am using Oracle SQL Developer. 回答1: There are multiple

问题 This question already has answers here : PHP: Return all dates between two dates in an array [duplicate] (26 answers) Closed 10 months ago . I have 2 dates $st_date = '2012-07-20'; $ed_date = '2012-07-27'; I want to display all dates from $st_date to $ed_date As: 2012-07-20 2012-07-21 2012-07-22 2012-07-23 2012-07-24 2012-07-25 2012-07-26 2012-07-27 I thought first count difference, run foreach < count, and add $i day to $st_date. But i don't want loop, it increases code. Any of direct date()

问题 I have a specific problem; I have data in the following format: # USER_ID SUBMISSION_DATE CONTRACT_REF 1 1 20/6 1:00 W001 2 1 20/6 2:00 W002 3 1 20/6 3:30 W003 4 4 20/6 4:00 W004 5 5 20/6 5:00 W005 6 5 20/6 6:00 W006 7 7 20/6 7:00 W007 8 7 20/6 8:00 W008 9 7 20/6 9:00 W009 10 7 20/6 10:00 W0010 Now I need to somehow calculate the time difference between the different submissions (uniquely identifiable). In other words: I have a table of submissions , in this table, there are all submissions

问题 I am formatting time stamp field to 'DD/MM/YYYY' format to get all processed records on that date. select count(*) from task_log where to_date (event_dt,'DD/MM/YYYY')= to_date('19/05/2015','DD/MM/YYYY'); The above query is returning 0 count. select count(*) from task_log where to_date (event_dt,'DD/MM/YYYY')= to_date('19/05/0015','DD/MM/YYYY'); The above query is returning 29 count. If I run: select event_dt from task_log where to_date (event_dt,'DD/MM/YYYY')= to_date('19/05/0015','DD/MM/YYYY

问题 I have a date (4/30/2012), an hour (4) and a minute (45). I need to convert that to an Oracle datetime value for comparison in a PLSQL/Oracle SELECT statement. Ideally, there would be a function like this (C# since I know it a little better): var date = "4/30/2012"; var hour = "4"; var minute = "45"; DateTime myDateTime = convertDateTime(date, hour, minute); I have a table with three columns to make up the date and time of an event. I have another table that has items that may or may not