I have a table called "Publicholidays" where in dates are stored as Varchar.
My query should fetch all values from say table xxxx between the user selected dates that exclude the weekends(sat,sun), public holidays. I am new to DB2 so can anyone suggest me ideas please
Note: in DB dates are stored as String.
Mistake #1 - Storing dates as strings. Let's hope you have at least stored them YYYY-MM-DD and not MM-DD-YYYY.
Mistake #2 - Instead of a "Publicholidays" table, you need a Calendar (aka Dates or date conversion) table. It should have a record for every day along with a few flag columns BUSINESS_DAY, WEEKEND, PUBLIC_HOLIDAY. Alternatively, you could have a single DAY_TYPE column with values for business day, weekend and holiday. You'll also want to have a STRING_DATE column to make conversion between your string date and a true date easier.
Google SQL Calender table and you'll find lots of examples and discussions.
Lastly, strongly consider fixing your DB to store dates in a date column.
Related
I am beginner in Backend technology and I am developing one query in Typeorm QueryBuilder + PostgreSQL.
My query is look like this :
But I can't convert my timestamp into following format. Can anyone who has expertise in it, please help me to select all records with timestamp in specific format.
I am suffering this things from last two days but still not find any solution. Actually I want to compare this date format in having clause. so I want to first select that date format then I can use that same method to compare column with current date and previous dates.
I need to create an attendence list showing days in rows and employee names in colums. The list will always cover one full month chosen in parameters.
How can I create a recordset of days of chosen month? I've done it in command section but, due to ERP system limitations, it must done otherways.
Thank you,
Przemek
A good approach is to create a Calendar table (aka Date Dimension in data warehousing lingo). It makes it easy to show days without any attendance. If you don't need that aspect, you can simply create a formula that returns the attendance date month's day, and Group on that formula. The Day() function gets you the day of month. For example,
Day ({Orders.Order Date})
If you search 'creating a data dimension or calendar table' you'll find many helpful sources such as this one: https://www.mssqltips.com/sqlservertip/4054/creating-a-date-dimension-or-calendar-table-in-sql-server/
For your case, I agree with the comments in that post about using date instead of integer as the primary key. Integer PK makes more sense for true data warehousing scenarios as opposed to legacy databases.
First of all im a starter,iam using eclipse.
I want to add current date and time of login in to db and search a day and find out the time between login and logout.
°What is the data type for the date colum in mysql ?
°Is it necessary separate column for date and time ?
°which one i want to import, java.util.date or java.sql.date ?
°In Java code simple date format or calender is better ?
Advanced thanks.....
You might want to read this:
Should I use field 'datetime' or 'timestamp'?
For example, if you have mysql populate the log record's date/time (using "DEFAULT CURRENT_TIMESTAMP" in your field definition), you will want to use timestamp. For certain situations where you fill a date value from your application, you may wish to use datetime. Be careful with timezones.
Here are the date functions in mysql:
https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html
DATEDIFF(), for example, will calculate the number of days between two datetimes. If you use unix timestamps, you can use standard arithmetic between the values to find the number of seconds between them, and then calculate minutes, hours, days, etc. by dividing appropriately.
This answer is focused on how to handle the dates in mysql. Not enough info to provide guidance on java.
Tableau is reading my dates wrong. I have 2 columns, Date and number for each day.
The date format is “yyyymmdd” i.e. (20160617) and per day number is integer. I am fetching this data directly from SQL server and my problem is, tableau is reading my dates wrong.
So I tried DATEPARSE() to convert my date.
My DATEPARSE function is : DATEPARSE(“yyyymmdd”,”Date”) , now after using DATEPARSE function, I get NULL for my dates.
Can anyone please help me why I get NULL for dates, my query returns 30-day data which is divided into per day count.
Sample after running the query on SQL
Date Per day number
20160617 215674
Tableau does not accept this date format and I applied DateParse(), which I guess is returning string since my date is null. I would ideally like to get the correct date so I can apply a trend line on my data.
Thanks in advance.
Cheers!
You aren't using DateParse() correctly. The second parameter, which you have as "Date", should be the name of the field you want parsed. So for example, if you store 20160617 in a field called my_date_as_integer, your function should be DateParse("yyyymmdd", [my_date_as_integer])
One of my customers would like to have a custom date column, where he could store the year only, a combination of month and year (without the day), or a classic date with day, month and year.
It should be possible to use this field for sorting the data. A "month-year" date should be considered as "01-month-year" for the sort, and a "year" date should be treated as "01-01-year" for the sort.
I could imagine two solutions to that:
Store the date in the standard "day-month-year" format, and keep in a separate column how the date was entered ("year", "month-year", "day-month-year"), so the approximate date can be displayed exactly how it was entered.
Use some sort of custom date column in the postgresql database.
Has anyone experience with that?
You could use date-time functions to extract date components. I don't think it has any sense to create additional columns. Also, some databases allow to create indexes by functions.