DB_FIELD_FILTER
Returns an array, from a given array of field names, containing a subset of the original array. The values in the array must meet the requirements that you specify in filter parameters.
Format
DB_FIELD_FILTER (Filter Strings, Field Strings)
Arguments
Filter Strings | Array of character strings that is similar to the macro parameter specification language used in Adams View: ■object_type = database_object_type uses the type specified as the database_object_type for field lookups. The value of database_object_type is one of the values returned by the function SELECT_TYPE (but cannot be a class name). ■t = type selects all fields that can hold an object of type. type can be the following subset of types from the macro language: | |
If type is: | The field holds: | |
Bool | A boolean value. | |
String | Strings | |
Real | Real numbers | |
Integer | Integer numbers | |
Point | Ordered triples, such as location and orientation. | |
Database_object_type | A database object | |
■c = n where  ; n = 0 means an open array, n > 0 means a fixed array of length exactly equal to n. ■alias = boolean indicates whether the field is or is not an alias for some other field. Values for boolean are: ♦True = field must be an alias. ♦False = field must not be an alias. If you do not specify an alias, then the field can be either an alias or not. ■assoc = relation indicates the field has a particular relationship to the object. Values for relation are: ■Child ■Reference ■Twoway | ||
Field Strings | List of field names you want to filter. | |
Example
The following is a typical calling sequence that produces all the real scalar fields for the spring damper object:
