#1396 merge() with ManyToMany throwing error Referential integrity constraint violation

src/test/java/org/tests/merge/MGroup.java

@@ -0,0 +1,34 @@
+package org.tests.merge;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class MGroup {
+
+  @Id
+  private long id;
+
+  private String name;
+
+  public MGroup(long id, String name) {
+    this.id = id;
+    this.name = name;
+  }
+
+  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;
+  }
+}

src/test/java/org/tests/merge/MMachine.java

@@ -0,0 +1,59 @@
+package org.tests.merge;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.ManyToMany;
+import javax.persistence.Version;
+import java.util.ArrayList;
+import java.util.List;
+
+@Entity
+public class MMachine {
+
+  @Id
+  private long id;
+
+  private String name;
+
+  @ManyToMany
+  private List<MGroup> groups = new ArrayList<>();
+
+  @Version
+  private long version;
+
+  public MMachine(String name) {
+    this.name = name;
+  }
+
+  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 long getVersion() {
+    return version;
+  }
+
+  public void setVersion(long version) {
+    this.version = version;
+  }
+
+  public List<MGroup> getGroups() {
+    return groups;
+  }
+
+  public void setGroups(List<MGroup> groups) {
+    this.groups = groups;
+  }
+}

src/test/java/org/tests/merge/TestMergeCustomer.java

@@ -20,6 +20,21 @@ public class TestMergeCustomer extends BaseTestCase {
 
   private Random random = new Random();
 
+  @Test
+  public void customerOnly_defaultOptions_expect_updateOnly() {
+
+    MCustomer mCustomer = partial("cust1", "(id,name,version)");
+    mCustomer.setName("NotCust0");
+
+    LoggedSqlCollector.start();
+
+    Ebean.merge(mCustomer);
+
+    List<String> sql = LoggedSqlCollector.stop();
+    assertThat(sql).hasSize(1);
+    assertThat(sql.get(0)).contains("update mcustomer set name=?, version=? where id=? and version=?");
+  }
+
   /**
    * So this is effectively the same as a stateless update.
    */

src/test/java/org/tests/merge/TestMergeM2M.java

@@ -0,0 +1,64 @@
+package org.tests.merge;
+
+import io.ebean.BaseTestCase;
+import io.ebean.Ebean;
+import io.ebean.MergeOptions;
+import io.ebean.MergeOptionsBuilder;
+import org.ebeantest.LoggedSqlCollector;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class TestMergeM2M extends BaseTestCase {
+
+  @Test
+  public void m2mMerge() {
+
+    MGroup group1 = new MGroup(1, "gone");
+    MGroup group2 = new MGroup(2, "gtwo");
+    MGroup group3 = new MGroup(3, "gthree");
+    MGroup group4 = new MGroup(4, "gfour");
+    MGroup group5 = new MGroup(5, "gfive");
+
+    Ebean.save(group1);
+    Ebean.save(group2);
+    Ebean.save(group3);
+    Ebean.save(group4);
+    Ebean.save(group5);
+
+    MMachine machine = new MMachine("mac1");
+    machine.getGroups().add(group1);
+    machine.getGroups().add(group2);
+    machine.getGroups().add(group3);
+
+    MergeOptions options = new MergeOptionsBuilder().addPath("groups").build();
+
+    LoggedSqlCollector.start();
+
+    Ebean.merge(machine, options);
+
+    List<String> sql = LoggedSqlCollector.current();
+    assertThat(sql).hasSize(3);
+    assertThat(sql.get(0)).contains("select");
+    assertThat(sql.get(1)).contains("insert into mmachine");
+    assertThat(sql.get(2)).contains("insert into mmachine_mgroup");
+
+    machine.setName("mac1-mod");
+    machine.getGroups().remove(group2);
+    machine.getGroups().remove(group3);
+    machine.getGroups().add(group4);
+    machine.getGroups().add(group5);
+
+    Ebean.merge(machine, options);
+
+    sql = LoggedSqlCollector.current();
+    assertThat(sql).hasSize(4);
+    assertThat(sql.get(0)).contains("select");
+    assertThat(sql.get(1)).contains("delete from mmachine_mgroup");
+    assertThat(sql.get(2)).contains("insert into mmachine_mgroup");
+    assertThat(sql.get(3)).contains("update mmachine");
+
+  }
+}