Sintassi dei valori letterali intervallo

La sintassi seguente viene usata per i valori letterali intervallo in ODBC.

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 ]

| secondi

years-value ::= datetime-value

months-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 | SECOND

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

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

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

quote ::= '

unsigned-integer ::= digit...