fixes #9

grails-app/domain/test/domain/college/Course.groovy

@@ -11,6 +11,6 @@ class Course {
 
     static hibernateFilters = {
         collegeFilter(condition: 'status = 1')
-        collegeFilter(collection: 'students')
+        collegeFilter(collection: 'students', joinTable: true)
     }
 }

grails-app/domain/test/domain/college/Pen.groovy

@@ -0,0 +1,7 @@
+package test.domain.college
+
+
+class Pen {
+    String name
+    Integer status = 1
+}

grails-app/domain/test/domain/college/Student.groovy

@@ -9,11 +9,13 @@ class Student {
 
     static hasMany = [
             courses: Course,
-            loans: Loan
+            loans: Loan,
+            pens: Pen
     ]
 
     static hibernateFilters = {
         collegeFilter()
         collegeFilter(collection: 'loans')
+        collegeFilter(collection: 'pens', joinTable: true)
     }
 }

src/groovy/org/grails/plugin/hibernate/filter/HibernateFilterBuilder.groovy

@@ -5,6 +5,7 @@ import grails.util.Metadata
 import org.codehaus.groovy.grails.commons.GrailsDomainClass
 import org.hibernate.cfg.Mappings
 import org.hibernate.engine.spi.FilterDefinition
+import org.hibernate.mapping.Collection
 import org.hibernate.type.TypeFactory
 import org.slf4j.Logger
 import org.slf4j.LoggerFactory
@@ -92,8 +93,15 @@ class HibernateFilterBuilder {
 			}
 		}
 
+        def filterArgs = [name, condition, true, null, null]
+
 		// now add the filter to the class or collection
-		entity.addFilter name, condition, true, null, null
+		if (entity instanceof Collection && options.joinTable) {
+			entity.addManyToManyFilter(*filterArgs)
+
+		} else {
+			entity.addFilter(*filterArgs)
+		}
 
 		// TODO: may be able to refactor this so that the factory creates the
 		// session with the filters rather than enabling them on each request

test/integration/org/grails/plugin/hibernate/filter/CollegeFilterSpec.groovy

@@ -42,7 +42,7 @@ class CollegeFilterSpec extends IntegrationSpec {
         new Course(name: 'course')
                 .addToStudents(name: 'valid', status: 1)
                 .addToStudents(name: 'invalid', status: 0)
-                .save(failOnError: true)
+                .save(failOnError: true, flush: true)
 
         sessionFactory.currentSession.clear()
 
@@ -57,11 +57,11 @@ class CollegeFilterSpec extends IntegrationSpec {
     @Issue('https://github.com/burtbeckwith/grails-hibernate-filter/issues/9')
     void 'query many-to-many relationship with HQL'() {
 
-        new Course(name: 'invalidCourse', status: 0).save(failOnError: true)
+        new Course(name: 'invalidCourse', status: 0).save(failOnError: true, flush: true)
         new Course(name: 'validCourse')
                 .addToStudents(name: 'valid', status: 1)
                 .addToStudents(name: 'invalid', status: 0)
-                .save(failOnError: true)
+                .save(failOnError: true, flush: true)
 
         sessionFactory.currentSession.clear()
 
@@ -77,6 +77,23 @@ class CollegeFilterSpec extends IntegrationSpec {
         courses[0].students.size() == 1
     }
 
+    @Issue('https://github.com/burtbeckwith/grails-hibernate-filter/issues/9')
+    void 'query unidirectional one-to-many relationship'() {
+
+        new Student(name: 'Mark')
+                .addToPens(name: 'valid pen', status: 1)
+                .addToPens(name: 'invalid pen', status: 0)
+                .save(failOnError: true, flush: true)
+
+        sessionFactory.currentSession.clear()
+
+        when:
+        def student = Student.findByName('Mark')
+
+        then:
+        student.pens.size() == 1
+    }
+
     void 'query one-to-many relationship with HQL'() {
 
         new Student(name: 'invalid', status: 0).save(failOnError: true)