#3664 Fix / support for extra JoinColumns on ManyToOne

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanPropertyAssoc.java

@@ -436,14 +436,15 @@ ImportedId createImportedId(BeanPropertyAssoc<?> owner, BeanDescriptor<?> target
     }
     TableJoinColumn[] cols = join.columns();
     if (!idProp.isEmbedded()) {
-      // simple single scalar id
-      if (cols.length != 1) {
-        CoreLog.log.log(ERROR, "No Imported Id column for {0} in table {1}", idProp, join.getTable());
-        return null;
-      } else {
-        BeanProperty[] idProps = {idProp};
-        return createImportedScalar(owner, cols[0], idProps, others);
+      // simple single scalar id, match on the foreign column, allow extra TableJoinColumn for #3664
+      String matchColumn = idProp.dbColumn();
+      for (TableJoinColumn col : cols) {
+        if (matchColumn.equals(col.getForeignDbColumn())) {
+          return createImportedScalar(owner, col, new BeanProperty[]{idProp}, others);
+        }
       }
+      CoreLog.log.log(ERROR, "No Imported Id column for {0} in table {1}", idProp, join.getTable());
+      return null;
     } else {
       // embedded id
       BeanPropertyAssocOne<?> embProp = (BeanPropertyAssocOne<?>) idProp;

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanPropertyAssocOne.java

@@ -128,16 +128,6 @@ private void initialiseAssocOne(String embeddedPrefix) {
           throw new PersistenceException("Cannot find imported id for " + fullName() + " from " + targetDescriptor
           + ". If using native-image, possibly missing reflect-config for the Id property.");
         }
-        if (importedId.isScalar()) {
-          // limit JoinColumn mapping to the @Id / primary key
-          TableJoinColumn[] columns = tableJoin.columns();
-          String foreignJoinColumn = columns[0].getForeignDbColumn();
-          String foreignIdColumn = targetDescriptor.idProperty().dbColumn();
-          if (!foreignJoinColumn.equalsIgnoreCase(foreignIdColumn)) {
-            throw new PersistenceException("Mapping limitation - @JoinColumn on " + fullName() + " needs to map to a primary key as per Issue #529 "
-              + " - joining to " + foreignJoinColumn + " and not " + foreignIdColumn);
-          }
-        }
       } else {
         exportedProperties = createExported();
         String delStmt = "delete from " + targetDescriptor.baseTable() + " where ";

ebean-ddl-generator/src/main/java/io/ebeaninternal/dbmigration/model/build/ModelBuildPropertyVisitor.java

@@ -195,7 +195,7 @@ public void visitOneImported(BeanPropertyAssocOne<?> p) {
       String dbCol = column.getLocalDbColumn();
       BeanProperty importedProperty = p.findMatchImport(dbCol);
       if (importedProperty == null) {
-        throw new RuntimeException("Imported BeanProperty not found?");
+        continue;
       }
       String columnDefn = ctx.getColumnDefn(importedProperty, true);
       String refColumn = importedProperty.dbColumn();

ebean-test/src/test/java/org/tests/model/m2o/MTJOrder.java

@@ -0,0 +1,45 @@
+package org.tests.model.m2o;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+
+@Entity
+public class MTJOrder {
+
+  @Id
+  private long id;
+
+  @Column(name = "org_id")
+  private long orgId;
+
+  @Column
+  private String other;
+
+  public Long id() {
+    return id;
+  }
+
+  public MTJOrder setId(Long id) {
+    this.id = id;
+    return this;
+  }
+
+  public Long orgId() {
+    return orgId;
+  }
+
+  public MTJOrder setOrgId(Long orgId) {
+    this.orgId = orgId;
+    return this;
+  }
+
+  public String other() {
+    return other;
+  }
+
+  public MTJOrder setOther(String other) {
+    this.other = other;
+    return this;
+  }
+}

ebean-test/src/test/java/org/tests/model/m2o/MTJTrans.java

@@ -0,0 +1,47 @@
+package org.tests.model.m2o;
+
+import jakarta.persistence.*;
+
+@Entity
+public class MTJTrans {
+
+  @Id
+  private long id;
+
+  @Column(name = "org_id")
+  private long orgId;
+
+  @ManyToOne
+  @JoinColumns({
+    @JoinColumn(name = "org_id", referencedColumnName = "org_id"), // extra join column, not strictly needed
+    @JoinColumn(name = "order_id", referencedColumnName = "id")
+  })
+  private MTJOrder order;
+
+  public Long id() {
+    return id;
+  }
+
+  public MTJTrans setId(Long id) {
+    this.id = id;
+    return this;
+  }
+
+  public Long orgId() {
+    return orgId;
+  }
+
+  public MTJTrans setOrgId(Long orgId) {
+    this.orgId = orgId;
+    return this;
+  }
+
+  public MTJOrder order() {
+    return order;
+  }
+
+  public MTJTrans setOrder(MTJOrder order) {
+    this.order = order;
+    return this;
+  }
+}

ebean-test/src/test/java/org/tests/model/m2o/TestMTJoinColumns.java

@@ -0,0 +1,48 @@
+package org.tests.model.m2o;
+
+import io.ebean.DB;
+import io.ebean.test.LoggedSql;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class TestMTJoinColumns {
+
+  @Test
+  void test() {
+    MTJTrans parent = new MTJTrans();
+    parent.setOrgId(51L);
+
+    DB.save(parent);
+
+    MTJTrans found = DB.find(MTJTrans.class)
+      .setId(parent.id())
+      .fetch("order")
+      .findOne();
+
+    assertThat(found.order()).isNull();
+
+    var order = new MTJOrder()
+      .setOrgId(51L)
+      .setOther("some");
+    DB.save(order);
+    found.setOrder(order);
+    DB.save(found);
+
+    LoggedSql.start();
+    MTJTrans found2 = DB.find(MTJTrans.class)
+      .setId(parent.id())
+      .fetch("order")
+      .findOne();
+
+    assertThat(found2.order()).isNotNull();
+    assertThat(found2.order().id()).isEqualTo(order.id());
+    assertThat(found2.order().other()).isEqualTo("some");
+
+    List<String> sql = LoggedSql.stop();
+    assertThat(sql).hasSize(1);
+    assertThat(sql.get(0)).contains("from mtjtrans t0 left join mtjorder t1 on t1.org_id = t0.org_id and t1.id = t0.order_id where t0.id = ?");
+  }
+}