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11.3.2. The TIME Type

MySQL retrieves and displays TIME values in 'HH:MM:SS' format (or 'HHH:MM:SS' format for large hours values). TIME values may range from '-838:59:59' to '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).

You can specify TIME values in a variety of formats:

  • As a string in 'D HH:MM:SS.fraction' format. You can also use one of the following “relaxed” syntaxes: 'HH:MM:SS.fraction', 'HH:MM:SS', 'HH:MM', 'D HH:MM:SS', 'D HH:MM', 'D HH', or 'SS'. Here D represents days and can have a value from 0 to 34. Note that MySQL does not store the fraction part.

  • As a string with no delimiters in 'HHMMSS' format, provided that it makes sense as a time. For example, '101112' is understood as '10:11:12', but '109712' is illegal (it has a nonsensical minute part) and becomes '00:00:00'.

  • As a number in HHMMSS format, provided that it makes sense as a time. For example, 101112 is understood as '10:11:12'. The following alternative formats are also understood: SS, MMSS, HHMMSS, HHMMSS.fraction. Note that MySQL does not store the fraction part.

  • As the result of a function that returns a value that is acceptable in a TIME context, such as CURRENT_TIME.

For TIME values specified as strings that include a time part delimiter, it is not necessary to specify two digits for hours, minutes, or seconds values that are less than 10. '8:3:2' is the same as '08:03:02'.

Be careful about assigning abbreviated values to a TIME column. Without colons, MySQL interprets values using the assumption that the two rightmost digits represent seconds. (MySQL interprets TIME values as elapsed time rather than as time of day.) For example, you might think of '1112' and 1112 as meaning '11:12:00' (12 minutes after 11 o'clock), but MySQL interprets them as '00:11:12' (11 minutes, 12 seconds). Similarly, '12' and 12 are interpreted as '00:00:12'. TIME values with colons, by contrast, are always treated as time of the day. That is, '11:12' mean '11:12:00', not '00:11:12'.

By default, values that lie outside the TIME range but are otherwise legal are clipped to the closest endpoint of the range. For example, '-850:00:00' and '850:00:00' are converted to '-838:59:59' and '838:59:59'. Illegal TIME values are converted to '00:00:00'. Note that because '00:00:00' is itself a legal TIME value, there is no way to tell, from a value of '00:00:00' stored in a table, whether the original value was specified as '00:00:00' or whether it was illegal.

For more restrictive treatment of invalid TIME values, enable strict SQL mode to cause errors to occur. See Section 5.2.5, “The Server SQL Mode”.


 
 
  Published under the terms of the GNU General Public License Design by Interspire