間隔常值語法

下列語法用於 ODBC 中的間隔常值。

interval-literal ：：= INTERVAL [+ | -] interval-string interval-qualifier

interval-string ：：= quote { year-month-literal day-time-literal | } quote

year-month-literal ：：= years-value |[ years-value -] months-value

day-time-literal ：：= day-time-interval time-interval |

day-time-interval ：：= days-value [hours-value [ ： minutes-value [： seconds-value ]]

time-interval ：：= hours-value [：minutes-value [： seconds-value ] ]

| minutes-value [： seconds-value ]

| seconds-value

years-value ：：= datetime-value

month-value ：：= datetime-value

days-value ：：= datetime-value

hours-value ：：= datetime-value

minutes-value ：：= datetime-value

seconds-value ：：= seconds-integer-value [.[ seconds-fraction ] ]

seconds-integer-value ：：= unsigned-integer

seconds-fraction ：：= unsigned-integer

datetime-value ：：= unsigned-integer

interval-qualifier ：：= start-field TO end-field single-datetime-field |

start-field ：：= non-second-datetime-field [（ interval-leading-field-precision ）]

end-field ：：= non-second-datetime-field |SECOND[（ interval-fractional-seconds-precision ）]

single-datetime-field ：：= non-second-datetime-field [（ interval-leading-field-precision ）] |SECOND[（ interval-leading-field-precision [， （ interval-fractional-seconds-precision ）]

datetime-field ：：= non-second-datetime-field |第二

non-second-datetime-field ：：= YEAR |MONTH |DAY |HOUR |分鐘

interval-fractional-seconds-precision ：：= unsigned-integer

interval-leading-field-precision ：：= unsigned-integer

quote ：：= '

unsigned-integer ：：= digit...