RemoveRecordset (Recordset subroutine): Difference between revisions
mNo edit summary |
m (→Examples) |
||
Line 25: | Line 25: | ||
==Examples== | ==Examples== | ||
< | <ol> | ||
<li>In the following example, the result of one <var>Find</var> is used to eliminate records | <li>In the following example, the result of one <var>Find</var> is used to eliminate records | ||
from the result of another <var>Find</var>. | from the result of another <var>Find</var>. | ||
Line 62: | Line 62: | ||
And <code>%first</code> is now the exclusive OR of the original <code>%first</code> | And <code>%first</code> is now the exclusive OR of the original <code>%first</code> | ||
and <code>%second</code>. | and <code>%second</code>. | ||
</ | </ol> | ||
==See also== | ==See also== |
Latest revision as of 23:51, 6 November 2012
Remove from a Recordset the records that are matched in input Recordset (Recordset class)
RemoveRecordset removes or "subtracts," from the method Recordset object's records, the records
in a second Recordset object.
Syntax
recordset:RemoveRecordset( recordset2)
Syntax terms
recordset | A non-null Recordset object. |
---|---|
recordset2 | A non-null Recordset object, which must have the same file context as recordset. |
Usage notes
- If the recordset2 argument is null, the request is cancelled.
- Since RemoveRecordset never adds records to a Recordset, there are no lock strength requirements for the method object or the input object.
Examples
- In the following example, the result of one Find is used to eliminate records
from the result of another Find.
%threaten is object recordSet in file orders %bigCust is object recordSet in file orders find records to %threaten status = 'ARREARS' end find find records to %bigCust company ='TOXICO' end find %threaten:removeRecordset(%bigCust)
- RemoveRecordset can be thought of as subtraction,
AddRecordset as an
OR, and AndRecordset as an AND.
The missing basic logical operation is an exclusive OR, which
is not implemented as a basic method because it is expected to
be rarely needed.
However, you can achieve an exclusive OR operation with the
provided methods, as in the following example:
%first is object recordSet in foo %second is object recordSet in foo %both is object recordSet in foo ... %both = %first:copy %both:andRecordset(%second) %first:addRecordset(%second) %first:removeRecordset(%both)
And
%first
is now the exclusive OR of the original%first
and%second
.