What difference between the DATE, TIME, DATETIME, and TIMESTAMP Types
I need to store both time and date in the mysql. So I used of
NOW() function for that. But I don't know what should I use for type column im phpmyadmin. It should be noted that
NOW() returns both time and date like this:
Here is a solution, I can use of a separator for separating date and time (
12:45:34) and then store them in the DATE type and TIME type individually. Or I can use of VARCHAR type for storing both of them in one column. But I think these ways are not standard. what is standard type for storing both date and time ?
Here is my query: (also I don't know why
NOW() function does not works)
INSERT INTO table (timedate) VALUES (NOW())
DATE: It is used for values with a date part but no time part. MySQL retrieves and displays DATE values in YYYY-MM-DD format. The supported range is
DATETIME: It is used for values that contain both date and time parts. MySQL retrieves and displays DATETIME values in YYYY-MM-DD HH:MM:SS format. The supported range is
1000-01-01 00:00:00 to
TIMESTAMP: It is also used for values that contain both date and time parts, and includes the time zone. TIMESTAMP has a range of
1970-01-01 00:00:01 UTC to
2038-01-19 03:14:07 UTC.
TIME: Its values are in HH:MM:SS format (or HHH:MM:SS format for large hours values). TIME values may range from
838:59:59. The hours part may be so large because the TIME type can be used not only to represent a time of day (which must be less than 24 hours), but also elapsed time or a time interval between two events (which may be much greater than 24 hours, or even negative).
What difference between the DATE, TIME, DATETIME, and , TIMESTAMP is four bytes vs eight bytes for DATETIME. Timestamps are also lighter on the database and indexed faster. The DATETIME type is used when you need values that contain both date and time information. MySQL retrieves and displays DATETIME values in 'YYYY-MM-DD HH:MM:SS' format. Difference between DATETIME & TIMESTAMP. Supported range for DATETIME is '1000-01-01 00:00:00' to '9999-12-31 23:59:59' while for TIMESTAMP, it is '1970-01-01 00:00:01' UTC to '2038-01-09 03:14:07' UTC. Prior to MySQL 5.6.4, TIMESTAMP requires 4 bytes (+3 bytes for fractional seconds) to store the data while DATETIME requires 8 bytes (+3 bytes for fractional seconds).
I have a slightly different perspective on the difference between a DATETIME and a TIMESTAMP. A DATETIME stores a literal value of a date and time with no reference to any particular timezone. So, I can set a DATETIME column to a value such as '2019-01-16 12:15:00' to indicate precisely when my last birthday occurred. Was this Eastern Standard Time? Pacific Standard Time? Who knows? Where the current session time zone of the server comes into play occurs when you set a DATETIME column to some value such as NOW(). The value stored will be the current date and time using the current session time zone in effect. But once a DATETIME column has been set, it will display the same regardless of what the current session time zone is.
A TIMESTAMP column on the other hand takes the '2019-01-16 12:15:00' value you are setting into it and interprets it in the current session time zone to compute an internal representation relative to 1/1/1970 00:00:00 UTC. When the column is displayed, it will be converted back for display based on whatever the current session time zone is. It's a useful fiction to think of a TIMESTAMP as taking the value you are setting and converting it from the current session time zone to UTC for storing and then converting it back to the current session time zone for displaying.
If my server is in San Francisco but I am running an event in New York that starts on 9/1/1029 at 20:00, I would use a TIMESTAMP column for holding the start time, set the session time zone to 'America/New York' and set the start time to '2009-09-01 20:00:00'. If I want to know whether the event has occurred or not, regardless of the current session time zone setting I can compare the start time with NOW(). Of course, for displaying in a meaningful way to a perspective customer, I would need to set the correct session time zone. If I did not need to do time comparisons, then I would probably be better off just using a DATETIME column, which will display correctly (with an implied EST time zone) regardless of what the current session time zone is.
TIMESTAMP type has a range of '1970-01-01 00:00:01' UTC to '2038-01-19 03:14:07' UTC and so it may not usable for your particular application. In that case you will have to use a
DATETIME type. You will, of course, always have to be concerned that the current session time zone is set properly whenever you are using this type with date functions such as
Should I use the datetime or timestamp data type in MySQL?, Both store the data in the "YYYY-MM-DD HH:MM: SS" format. Both include a date as well as a time part. Automatic initialization can happen for� In spite of these similarities they are having the following differences − Range − Datetime data type supports a date along with time in the range between 1000-01-01 00:00:00 and 9999-12-31 23:59:59. But timestamp data type supports a date along with time in the range between ‘1970-01-01 00:00:01’ to ‘2038-01-19 08:44:07’.
Saty described the differences between them. For your practice, you can use
datetime in order to keep the output of
CREATE TABLE Orders ( OrderId int NOT NULL, ProductName varchar(50) NOT NULL, OrderDate datetime NOT NULL DEFAULT NOW(), PRIMARY KEY (OrderId) )
You can read more at w3schools.
Difference Between MySQL DATETIME And TIMESTAMP DataTypes, DATE. A dateisa three-part value representing a year, month, and day in the rangeof 0001-01-01 to 9999-12-31. TIME. A timeisa three-part value representing a time of day in hours, minutes, andseconds, in the range of 00.00.00 to 24.00.00. TIMESTAMP.
The differences are covered at the PostgreSQL documentation for date/time types. Yes, the treatment of TIME or TIMESTAMP differs between one WITH TIME ZONE or WITHOUT TIME ZONE. It doesn't affect how the values are stored; it affects how they are interpreted. The effects of time zones on these data types is covered specifically in the docs.
TIMESTAMP used to track changes to records, and update every time when the record is changed. DATETIME used to store specific and static value which is not affected by any changes in records. TIMESTAMP also affected by different TIME ZONE related setting. DATETIME is constant.
Help and Example Use. Some typical uses for the Date Calculators; API Services for Developers. API for Business Date Calculators; Date Calculators. Time and Date Duration – Calculate duration, with both date and time included
- This article from the MySQL Documentation explains this well.
- NEVER store a date or time as a varchar.
- @RobertMauro - There are all kinds of issues with doing that. Data size, indexing performance, query performance, ambiguity of various string formats, etc. Also, milliseconds only require 3 digits. MySQL supports up to microseconds (6 digits). The 7 digit formats usually (but not always) originate from Microsoft .NET or SQL Server, and it is nearly impossible to actually get an accurate timestamp from a system clock at that scale anyway. One might as well truncate or round to the nearest microsecond to store in MySQL.
- Ah, I see. Alas, since MySQL only supports 6 digits on
TIMESTAMPvalues, then yes - you are correct. You may need to store that full timestamp somewhere else, such as in a
VARCHARfield so you can exactly match on it. I'd recommend using ISO8601 extended format exclusively and consistently. It might still help to keep a secondary column of the native type to use for range queries, depending on your needs. Great discussion, BTW. ;)
- @MattJohnson Brilliant suggestion, I think I need more coffee since I didn't think about it. I'll index and utilize a datetime(6) field for queries, and accurately store the value presented to us in a varchar. Thanks!
- What is
- @Sajad - UTC is Coordinated Universal Time. Be sure to recognize that
TIMESTAMPdiffer in how they convert to and from local time to UTC.
- this doesnt even really tell the difference between
- @Anthony No. The
DATETIMEexample does not include a timezone, whereas the
- @BenJohnson fair enough. somebody ought to edit the answer so that its more understandable then
- Excellent point. Note that
Timestampcan only handle dates 1970 through 2038-01-19, whereas
DateTimecan handle years 1000 through 9999. Timestamp's primary use is for datetimes reasonably near the present. It will probably be extended to 2116 before we get to year 2038 When using
DateTime, I recommend having the input app convert to/from UTC. If that is done consistently, then DateTime can be considered UTC time, removing the ambiguity.
- Keep in mind that 2038 problems don't wait for 2038 to happen, they can happen right now - for example, if I have a database of retirement funds which have a 20-year-target-horizon and I want to store that date, it will already wrap around and very bad things will happen.
- Real life example of problems already happening related to Y2K38
- @Tim: Good point. Clearly if you need to work with dates that go to 2038 and beyond, then the only option is to use
DATETIMEtypes and consistent session time zone settings when initializing, displaying and comparing. I will add an update to my answer.
- @Booboo It's a great answer and I appreciate you posting it - just want to make clear to anybody stopping by the danger of 2038 and that it's happening now. I wish we had support for a field with time zone independence and post-2038 support! I guess one option is to use
datetimeand convert to UTC before inserting, but that's more error-prone on the client side