First (query directive)
From WandoraWiki
(Difference between revisions)
| (2 intermediate revisions by one user not shown) | |||
| Line 11: | Line 11: | ||
== Examples == | == Examples == | ||
| − | importPackage(org.wandora.query2); | + | importPackage(org.wandora.query2); |
| − | new If( | + | new If( |
| − | + | new BaseName().where("#DEFAULT","!=",null), | |
| − | + | new BaseName(), | |
| − | + | new First(new SubjectIdentifiers()) | |
| − | ) | + | ) |
| − | .from(new Instances()) | + | .from(new Instances()) |
This returns the base names of the instances of the input topic or the first subject identifier if the base name is not defined. | This returns the base names of the instances of the input topic or the first subject identifier if the base name is not defined. | ||
| + | |||
| + | [[Category:Query directives]] | ||
Latest revision as of 10:57, 21 August 2009
[edit] Description
Returns the first or the first N rows of specified directive. May return less than specified number of rows if the inner directive does not return that many rows.
[edit] Constructor
First(Directive directive) - Returns the first row of directive.
First(int count, Directive directive) - Returns the first count rows of directive
[edit] Examples
importPackage(org.wandora.query2);
new If(
new BaseName().where("#DEFAULT","!=",null),
new BaseName(),
new First(new SubjectIdentifiers())
)
.from(new Instances())
This returns the base names of the instances of the input topic or the first subject identifier if the base name is not defined.
