I have an object that is generated from XSDs, so I can't change it. In it I have a String DATE and a String TIME (representing the time of day without the date).
DATE = yyyy-mm-dd
TIME = hh:MM:ss:mmmm
In the OracleDB, I don't want to represent these as VARCHAR. I'd like to use DATE or DATETIME. Therefore, I'd need to map both DATE + TIME to one single column, DATETIME.
This is not possible. You can map two columns to a single property (using composites or user types) but not the other way around.
Using the same column name twice in the mapping file usually results in strange exceptions (index out of bounds).
I would use two columns in the database. Convert them to DATE-kind data types using a user type.
Related
The fields look as described above. They are time fields from SQL imported as a varchar. I had to format as date in tableau. There can be NULL values, so I am having a tough time getting over that. Tableau statement I have is only ([time spent])+([time waited])+([time solved)].
Thank you!
If you only want to use the result for a graphical visualization of what took the longest, you can split and add all the values into seconds and using it into your view. E.g.
In this case the HH:MM:SS fields are Strings for Tableau.
The formula used to sum the three fields is:
//transforms everything into seconds for each variable
zn((INT(SPLIT([Time Spent],':',1))*3600))
+
zn((INT(SPLIT([Time Spent],":",2))*60))
+
zn((INT(SPLIT([Time Spent],":",3))))
+
zn((INT(SPLIT([Time Waited],':',1))*3600))
+
zn((INT(SPLIT([Time Waited],":",2))*60))
+
zn((INT(SPLIT([Time Waited],":",3))))
+
zn((INT(SPLIT([Time Solved],':',1))*3600))
+
zn((INT(SPLIT([Time Solved],":",2))*60))
+
zn((INT(SPLIT([Time Solved],":",3))))
Quick explanation of the formula:
I SPLIT every field three times, one for the hours, minutes and seconds, adding all the values.
There is an INT formula that will convert the strings into integers.
There is also a ZN for every field - this will make Null fields become Zeros.
You can also use the value as integer if you want, e.g. the Case A has a Total Time of 5310 seconds.
The best approach is usually to store dates in the database in a date field instead of in a string. That might mean a data prep/cleanup step before you get to Tableau, but it will help with efficiency, simplicity and robustness ever after.
You can present dates in many formats, including hh:mm, when the underlying representation is a date datatype. See the custom date options on the format pane in Tableau for example. But storing dates as formatted strings and converting them to something else for calculations is really doing things the hard way.
If you have no choice but to read in strings and convert them to dates, then you should look at the DateParse function.
Either way, decide what a null date means and make sure your calculations behave well in that case -- unless you can enforce that the date field not contain nulls in the database.
One example would be a field called Completed_Date in a table of Work_Orders. You could determine that a null Completed_Date meant the work order had not been fulfilled yet, and thus allow nulls for that field. But you could also have the database enforce that another field, say Submitted_Date, could never be null.
Say I have two timestamp type columns timestamp_column1 and timestamp_column2
I want to compare if timestamp_column1 is greater than timestamp_column2.
How do I compare these two timestamps ? Does comparison operators work properly with timestamp on Oracle?
timestamp_column1 > timestamp_column2
Is this correct??
Or do I have to wrap them in some function to compare them with each other
like to_timestamp(timestamp_column1) > to_timestamp(timestamp_column2)
?
As long as the "timestamp" columns are truly using one of the date or timestamp data types, then yes the usual relational operators will work.
The only time you need to wrap a timestamp in a function is if it's erroneously stored as a string, or if you want to manipulate it in some way such as truncating it to the hour, day, week, month, year or other less discreet unit of time.
I'm stuck with sorting and showing the correct date in Xpages.
It is saved in format "dd.MM.yyyy" and it's a string.
Now why it's a string and formated that way, is because my boss has special wishes. And when I want to sort it from the newest date to older it does something like this:
26.05.2015
24.06.2014
22.04.2015
21.04.2015
20.03.2014
It starts sorting by day.
Is there a way to make it sort it like it should?
I see that i can write a Computed value to Sort column in view column header for date. But i don't know how to even start.
Change the underlying Notes view to get your date column into right order.
Convert the date strings to real date values in views column formula. Assuming your field is called DateText then your formula would be
#Date(#ToNumber(#Right(DateText; 4));
#ToNumber(#Middle(DateText; 3; 2));
#ToNumber(#Left(DateText; 2)))
It would be easier to use just #ToTime(DateText) but this can fail depending on server's local settings. Your date string format would work for a server with German locale settings but not for US. That's why is my suggested solution "safer".
If the date time value doesn't solve your problem and you do not transform your date via #Text (as mentioned in the comments) then create another (hidden) column BEFORE your column that should be displayed. Make this a true date (from your item), sort it and unsort the column to display.
Otherwise use this formula in the newly created sorted column:
#Text(#Year(yourDate))+"-"+#Right("00"+#Text(#Month(yourDate));2)+"-"+#Right("00"+#Text(#Day(yourDate));2)
If I'm defining a table in Hive, and will be partitioning based on date, and my dates are in the format YYYYMMDD, which should I choose for the type, int or string?
If it was just a field, and therefore in the files I'm supplying for the table, I could see using a string, even if only so that I can search for and identify malformed entries that might work their way into my data. But since I will be specifying the partition as part of the load process, I know I'll always have correctly formed values.
When used in a Where clause, the partition field will normally be equality or less-than/greater-than logic.
Dates are typically treated as strings in Hive. If you look at all the date manipulation UDFs available, they use string types, so if you were using integers you would have to cast them every time.
Conceptually also I think it makes more sense to use strings, your YYYYMMDD is just a literal representation of a date object, but it is implicitly equivalent to something like YYYY-MM-DD or DDMMYYYY. So if you were using an integer here, it becomes painful to do such comparisons.
Note that you can also compare strings in Hive with equality/greater/lower-than operators, if you want to select a range of partitions you can easily do that with these operators.
The only case I would see using a "date" as an integer is using a timestamps (Unix-style) because it is a continuous value and represents a real measurable quantity.
Because YYYY-MM-DD is the standard for date representation and is the output of hive's to_date() UDF
it also allows you to do lazy things like select * from foo where day>'2013'
http://xkcd.com/1179/
For few columns from the source i.e .csv file, we are having values like 1:52:00, 14:45:00.
I am supposed to load to the Oracle table.
Which data type should I choose in Target as well as source?
Should i be doing any thing in the expression transformation?
Use SQLLDR to load the data into database with the format described as in the link
http://docs.oracle.com/cd/B19306_01/server.102/b14200/sql_elements004.htm
ie.'HH24:MI:SS'
Oracle does not support time-only values, it supports dates (with a time component).
You have a few options:
Store the value as a string, perhaps providing a leading zero for
the hour.
Store the value as the number of seconds (or minutes) past midnight.
Store the value as the time component of some arbitrarily defined date, for
example 0001-JAN-01 01:52:00 and 0001-Jan-01 14:45:00. Tell your report writers to ignore the date portion of the value.
Your source datatype will be string(8). Use LPAD to add leading zeroes.