I need to insert a year(eg:1988 ,1990 etc) in a database. When I used Date or Datetime
data type, it is showing errors. Which datatype should I use.
regular 4 byte INT is way too big, is a waste of space!
You don't say what database you're using, so I can't recommend a specific datatype. Everyone is saying "use integer", but most databases store integers as 4 bytes, which is way more than you need. You should use a two byte integer (smallint on SQL Server), which will conserve space.
If you need to store a year in the database, you would either want to use an Integer datatype (if you are dead set on only storing the year) or a DateTime datatype (which would involve storing a date that basically is 1/1/1990 00:00:00 in format).
Hey,you can Use year() datatype in MySQL
It is available in two-digit or four-digit format.
Note: Values allowed in four-digit format: 1901 to 2155. Values allowed in two-digit format: 70 to 69, representing years from 1970 to 2069
Storing a "Year" in MSSQL would ideally depend on what you are doing with it and what the meaning of that "year" would be to your application and database. That being said there are a few things to state here. There is no "DataType" for Year as of 2012 in MSSQL. I would lean toward using SMALLINT as it is only 2 bytes (saving you 2 of the 4 bytes that INT demands). Your limitation is that you can not have a year older than 32767 (as of SQL Server 2008R2). I really do not think SQL will be the database of choice ten thousand years from now let alone 32767. You may consider INT as the Year() function in MSSQL does convert the data type "DATE" to an INT. Like I said, it depends on where you are getting the data and where it is going, but SMALLINT should be just fine. INT would be overkill ... unless you have other reasons like the one I mentioned above or if the code requirements need it in INT form (e.g. integrating with existing application). Most likely SMALLINT should be just fine.
Just a year, nothing else ?
Why not use a simple integer ?
Use integer if all you need to store is the year. You can also use datetime if you think there will be date based calculations while querying this column
Storage may be only part of the issue. How will this value be used in a query?
Is it going to be compared with another date-time data types, or will all the associated rows also have numeric values?
How would you deal with a change to the requirements? How easily could you react to a request to replace the year with a smaller time slice? i.e. Now they want it broken down by quarters?
A numeric type can be easily used in a date time query by having a look-up table to join with containing things like the start and stop dates (1/1/X to 12/31/x), etc..
I don't think using an integer or any subtype of integer is a good choice. Sooner or later you will have to do other date like operations on it. Also in 2019 let's not worry too much about space. See what those saved 2 bytes costed us in 2000.
I suggest use a date of year + 0101 converted to a true date. Similarly if you need to store a month of a year store year + month + 01 as a true date.
If you have done that you will be able to properly do "date stuff" on it later on
Related
I've been having problems with a query that returns data between two date times, the query that I'm trying to fix is this one
pay.date BETWEEN '01/06/2020 00:28:46 a. m.' AND '01/06/2020 10:38:45 a. m.'
That query does not detect the a. m. part and if I have a payment at 10 am and 10 pm it will detect both payments as the t. t. part is not detected, I've been searching for a while now with no luck, thanks in advance :)
Do the filtering by an actual datetime type:
cast(replace(replace(pay.date, ' a. m.', 'am'), ' p. m.', 'pm') as datetime)
It might be better to use convert() so you can specify the proper format. If you can't supply the date literals in a readily convertible format then do a similar replace and cast on those too.
Use a literal format that is unambiguous and not dependent on runtime or connection settings. More info in Tibor's discussion.
In this case:
where pay.date between '20200601 00:28:46' and '20200601 10:38:45'
Notice that I assume June, not January - adjust as needed. Between is inclusive and be certain that you understand the limitations of the datatype for pay.date. If datetime, the values are accurate to 3ms. Verify that your data is consistent with your assumption about accuracy to seconds.
I'm looking to confirm a theory of mine, but I really need to be sure first.
I have laravel 5.0 and SQL Server 2012.
when I have fields with the default datetime, I can't insert values with more than 3 microsecond spaces because the database errors out.
So if I set it to datetime2(3) I can insert a lot more microsecond spaces but only the first ones will be preserved that fit in the field.
If I set it the SQL Server grammar to 'Y-m-d H:i:s.u' it will try to insert a number with 6 spaces every time.
What i'm looking for is that carbon will not have issues with the fact that the database will return less than 6 numbers(namely the 3) and will continue to work properly in all cases without exceptions when I call a toArray() in laravel or something like that.
I can't do datetime2(7) because carbon then complains about trailing data.
So in short
Does carbon, with set dateformat Y-m-d H:i:s.u, gladly always accept a number with only 3 decimal place points, and happily insert a 6 decimal point into the database and not object that the database only saves up to 3 points?
For people looking into this issue:
I'm using datetime2(3) data fields in the database, and I use the Y-m-d H:i:s.u date notation without issue now for the last 2 months, even with all the wonky date stuff I sometimes throw at it, I've had no issues.
Only issues I had when I accidentally used datetime or datetime2(7)
Need to get entities filtering by month instead of complete date values (E.g. Birthdays) using Google App Engine Text Search. On verifying GAE docs, I think it is not possible to query date fields by month directly.
So in order to filter them by month/date, we consider saving each date sub value like Date(DD), Month(MM) and Year(YYYY) as separate NUMBER field along with complete date field.
I verified locally that we can achieve by saving like this. But is this the correct way of saving dates by splitting each field when we want to query on date sub values?
Is there any known/unknown limit on number of fields per document apart from 10GB size limit in GAE Text Search?
Please suggest me.
Thanks,
Naresh
The only time NUMBER or DATE fields make sense is if you need to query on ranges of values. In other cases they are wasteful.
I can't tell from your question exactly what queries you want to run. Are you looking for a (single) specific day of the month (e.g., January 6 -- of any year)? Or just "anything in June (again, without regard to year)"? Or is it a date range: something like January 20 through February 19? Or July 1 through September 30?
If it's a range then NUMBER values may make sense. But if it's just a single specific month, or a single month and day-of-month combination, then you're better off storing month and day as separate ATOM fields.
Anything that looks like a number, but isn't really going to be searched via a numerical range, or done arithmetic on, isn't really a number, and is probably best stored as an ATOM. For example, phone numbers, zip codes (unless you're terribly clever and wanting to do something like "all zip codes in San Francisco look like 941xx" -- but even then if that's what you want to do, you're probably better off just storing the "941" prefix as an ATOM).
Ok, I can't understand this thing.
A customer of mine has a legacy Windows application (to produce invoices) which stores date values as integers.
The problem is that what is represented like '01.01.2002' (value type: date) is indeed stored in SQL Server 2000 as 731217 (column type: integer).
Is it an already known methodology to convert date values into integers (for example - I don't know - in order to make date difference calculations easier?)
By the way, I have to migrate those data into a new application, but for as much I googled about it I can't figure out the algorithm used to apply such conversion.
Can anybody bring some light?
It looks like the number of days since Jan 1st 0000 (although that year doesn't really exists).
Anyway, take a date as a reference like Jan 1st 2000 and look what integer you have for that date (something like 730121).
You then take the difference between the integer you have for a particular date and the one for your reference date and you that number of days to your reference date with the DATEADD function.
DATEADD(day, *difference (eg 731217 - 730121)*, *reference date in proper SQLServer format*)
You can adjust if you're off by a day a two.
I have a legacy application where the input is a date string, i.e.:
06/12/2009
The format of the input is always a string, and is consistent, it's always dd/mm/yyyy
At the moment the legacy app just INSERTS this in a DateTime fields. Obviously if the Localization Culture settings of the Server change, we have a bug.
Two questions:
One:
Whats the safest way to store Dates in SQLServer in this situation?
Is there a format that will always be correctly interpreted regardless of the order of day and month?
Two:
What settings exactly determines the culture of a SQLServer DB, is it an OS setting, or a setting of that DB, or what?
cheers
Format YYYY-MM-DD is unambiguous, meaning that SQL Server won't confuse the month
and day when converting a string value to DATETIME. (I've never experienced a problem with an implicit conversion using that format using the four digit year.)
The "safest" (and most convenient) way to store date values in SQL Server is to use DATETIME datatype.
Use the CONVERT function to explicitly specify the input and output formats when converting between DATETIME and strings.
SQL Server 2005 Documentation on CONVERT style argument values:
http://msdn.microsoft.com/en-us/library/ms187928(SQL.90).aspx
To convert a string representation to DATETIME datatype:
select CONVERT(datetime, '2009-06-03', 20)
The first argument is datatype to convert to, the second argument is the expression to be converted, the third argument is the style.
(style 20 is ODBC Canonical format = 'YYYY-MM-DD HH:MI:SS' (24 hour clock)
[FOLLOWUP]
To convert a DATETIME expression (e.g. getdate() to VARCHAR in 'YYYY-MM-DD' format:
select CONVERT(varchar(10), getdate(), 20)
Note that specifying varchar(10) gets you just the first 10 characters of the etnire 'YYYY-MM-DD HH:MM:SS' format.
[/FOLLOWUP]
As to what determines the default formats, that's going to be research. We avoid the issues caused by default formats by specifying the formats.
I would recommend storing all dates in UTC time when they are placed into the database. It will be consistent that way.
Storing dates like this seems to work well...
YYYY-MM-DD
See SET DATEFORMAT. The SQL 'culture' is set by SET LANGUAGE at a session level. SQL Server has its own date format settings, independent of the hosting OS. This is for several reasons: ANSI compliance, to prevent OS changes from affecting applications using the database hosted on that host and not least is compatibility, the SQL long predates the OS is currently running on.
Keep in mind that DATA is not its PRESENTATION. In this case that DATA is a DATE or DATETIME, regardless of how you show them.
As for inserting/updating/comparing datetime values, I quote the BOL:
When specifying dates in comparisons
or for input to INSERT or UPDATE
statements, use constants that are
interpreted the same for all language
settings: ADO, OLE DB, and ODBC
applications should use the ODBC
timestamp, date, and time escape
clauses of:
{ ts 'yyyy-mm-dd
hh:mm:ss[.fff] '} such as: { ts
'1998-09-24 10:02:20' }
{ d 'yyyy-mm-dd'} such as: { d '1998-09-24' }
{ t 'hh:mm:ss'} such as: { t '10:02:20'}
I can assure you that, if you use this formats they will always work, regardless of the locale of you server
I'm a bit conservative in these matters, but I prefer to use separate Year / Month / Day fields in the table, rather than a Date field that uses a DBMS-specific data type. It certainly takes more space, but the lack of ambiguity and increased portability is worth it to me.
The price you pay is that you don't get free date/time arithmetic and sorting, but it's easy enough to do yourself or by a slightly more complex "ORDER BY" clause.
I agree with the advice from spencer7593, but please be aware that using cast or convert without a format can give unexpected results. This T-SQL query returns 12, not 1.
set language British
select month(CAST('2016-01-12' AS datetime))
Normally I prefer to insert as
insert into tbl values('yyyyMMdd')
Then, itll be inserted in proper format based on db.