When specifying field names, usually for displaying or sorting, there is additional syntax that can affect how the fields are used and displayed.
The general syntax is
[+-]external_field_name[-precision][!verbosity][<>]described in detail below. An "external_field_name" is either a field name or one of its alternatives, as described in the field name descriptions.
When no specific fields are specified for displaying or sorting,
defaults are of course chosen.
When selecting other than the defaults,
it's often the case that one wants to make a simple modification
to the defaults.
So to avoid having to re-specify not only the change one wants,
but all of the defaults as well, a leading +
will add to the defaults, and a leading -
will remove from the defaults.
E.g. to include the cost_estimate
field,
specify +cost_estimate
.
The default sort order of a field is field specific,
intended to be what people want most often.
A specific sort order can be specified by appending
a <
or >
:
< | ascending sort order |
---|---|
> | descending sort order |
It makes no sense to specify a sort order in a field specification used for anything but sorting.
The precision of a value can be used to determine where titles appear when sorting and grouping records. It can also be used to simplify the result of displayed data, although that's less common.
All fields will accept any of the following a general precision specifications.
none | results in every value replaced with a single value (undefined). That's useful only as a way to avoid grouping records after sorting. E.g. when sorting by age one might not need to see titles separating the records for some specific interval. |
---|---|
low |
results in a field specific precision
that most would consider to be low. The specific precision is deliberately not documented, as it could change according to general preference. |
medium |
results in a field specific precision
that most would consider to be medium. The specific precision is deliberately not documented, as it could change according to general preference. |
high | always leaves the data alone; there's no reduction in precision. E.g. dates remain accurate to the second. |
In addition, there are field specific precisions, determined by the type of the data.
Dates |
One of
day, week, month, term, or year. |
---|---|
Intervals |
One of
second, minute, hour, day, week, month, term, or year. |
Attributes |
The precision is the number of words in the attribute.
E.g. applying a precision of 1 to a Serviceof Student Computing Environment — Mac Labsresults in Student Computing Environment. |
Email Addresses | A precision of "userid" converts the address to the first 8 characters of the userid part, i.e. the campus convention for the shortest unique part of the userid. It's useful when dealing with an inconsistent use of short and long userids. |
Priority |
A precision may be 0or 1, being the number of digits after the decimal point. |
The verbosity of the field display is one of
How they affect display is field specific. This specification overrides the verbosity implied by an "external" field name. E.g. "Unit" (an "external" field name) is the Department in terse form, while "Unit!verbose" uses the verbose form.