#1228 - Add support to not generate FK Constraint when @JoinColumn(foreignKey=@ForeignKey(ConstraintMode.NO_CONSTRAINT))

src/main/java/io/ebeaninternal/server/deploy/PropertyForeignKey.java

@@ -10,6 +10,19 @@ public class PropertyForeignKey {
   private final ConstraintMode onDelete;
   private final ConstraintMode onUpdate;
 
+  /**
+   * Construct for "No Constraint".
+   */
+  public PropertyForeignKey() {
+    this.noConstraint = true;
+    this.noIndex = false;
+    this.onDelete = ConstraintMode.GLOBAL_DEFAULT;
+    this.onUpdate = ConstraintMode.GLOBAL_DEFAULT;
+  }
+
+  /**
+   * Construct for the mapping annotation.
+   */
   public PropertyForeignKey(DbForeignKey dbForeignKey) {
     this.noIndex = dbForeignKey.noIndex();
     this.noConstraint = dbForeignKey.noConstraint();

src/main/java/io/ebeaninternal/server/deploy/parse/AnnotationAssocOnes.java

@@ -16,8 +16,10 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.persistence.Column;
+import javax.persistence.ConstraintMode;
 import javax.persistence.Embedded;
 import javax.persistence.EmbeddedId;
+import javax.persistence.ForeignKey;
 import javax.persistence.Id;
 import javax.persistence.JoinColumn;
 import javax.persistence.JoinTable;
@@ -131,6 +133,7 @@ public class AnnotationAssocOnes extends AnnotationParser {
       if (!joinColumn.nullable()) {
         prop.setNullable(false);
       }
+      checkForNoConstraint(prop, joinColumn);
     }
 
 
@@ -171,6 +174,13 @@ public class AnnotationAssocOnes extends AnnotationParser {
     }
   }
 
+  private void checkForNoConstraint(DeployBeanPropertyAssocOne<?> prop, JoinColumn joinColumn) {
+    ForeignKey foreignKey = joinColumn.foreignKey();
+    if (foreignKey != null && foreignKey.value() == ConstraintMode.NO_CONSTRAINT) {
+      prop.setForeignKey(new PropertyForeignKey());
+    }
+  }
+
   private String errorMsgMissingBeanTable(Class<?> type, String from) {
     return "Error with association to [" + type + "] from [" + from + "]. Is " + type + " registered?";
   }

src/test/java/org/tests/ddl/DfkNoneViaJoin.java

@@ -0,0 +1,50 @@
+package org.tests.ddl;
+
+import javax.persistence.ConstraintMode;
+import javax.persistence.Entity;
+import javax.persistence.ForeignKey;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+
+@Entity
+public class DfkNoneViaJoin {
+
+  @Id
+  long id;
+
+  String name;
+
+  @ManyToOne
+  @JoinColumn(name = "one_id", foreignKey = @ForeignKey(ConstraintMode.NO_CONSTRAINT))
+  DfkOne one;
+
+  public DfkNoneViaJoin(String name, DfkOne one) {
+    this.name = name;
+    this.one = one;
+  }
+
+  public long getId() {
+    return id;
+  }
+
+  public void setId(long id) {
+    this.id = id;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public void setName(String name) {
+    this.name = name;
+  }
+
+  public DfkOne getOne() {
+    return one;
+  }
+
+  public void setOne(DfkOne one) {
+    this.one = one;
+  }
+}

src/test/java/org/tests/ddl/TestForeignKeyModes.java

@@ -30,6 +30,24 @@ public class TestForeignKeyModes extends BaseTestCase {
   }
 
 
+  @Test
+  public void noneViaJoin() {
+
+    DfkOne one = new DfkOne("one2");
+    Ebean.save(one);
+
+    DfkNoneViaJoin none = new DfkNoneViaJoin("none2", one);
+    Ebean.save(none);
+
+    // fails unless there is no Foreign key ...
+    Ebean.delete(one);
+
+    DfkNoneViaJoin found = Ebean.find(DfkNoneViaJoin.class, none.getId());
+    assertThat(found).isNotNull();
+    // we still reference one ... even though it does not exist anymore
+    assertThat(found.getOne()).isNotNull();
+  }
+
   @Test
   public void setNullOnDelete() {