#529 - @OneToOne with @JoinColumn to non primary key throws Data conversion error

src/main/java/com/avaje/ebeaninternal/server/deploy/BeanPropertyAssocOne.java

@@ -101,14 +101,23 @@ public class BeanPropertyAssocOne<T> extends BeanPropertyAssoc<T> {
         // no imported or exported information
       } else if (!oneToOneExported) {
         importedId = createImportedId(this, targetDescriptor, tableJoin);
+        if (importedId.isScalar()) {
+          // limit JoinColumn mapping to the @Id / primary key
+          TableJoinColumn[] columns = tableJoin.columns();
+          String foreignJoinColumn = columns[0].getForeignDbColumn();
+          String foreignIdColumn = targetDescriptor.getIdProperty().getDbColumn();
+          if (!foreignJoinColumn.equalsIgnoreCase(foreignIdColumn)) {
+            throw new PersistenceException("Mapping limitation - @OneToOne @JoinColumn 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.getBaseTable() + " where ";
-
         deleteByParentIdSql = delStmt + deriveWhereParentIdSql(false);
         deleteByParentIdInSql = delStmt + deriveWhereParentIdSql(true);
-
       }
     }
   }

src/test/java/com/avaje/tests/model/onetoone/OCompany.java

@@ -0,0 +1,21 @@
+package com.avaje.tests.model.onetoone;
+
+import com.avaje.tests.model.basic.BasicDomain;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+
+@Entity
+public class OCompany extends BasicDomain {
+
+  @Column(length = 50, unique = true)
+  public String corpId;
+
+  public String getCorpId() {
+    return corpId;
+  }
+
+  public void setCorpId(String corpId) {
+    this.corpId = corpId;
+  }
+}

src/test/java/com/avaje/tests/model/onetoone/ORoadShowMsg.java

@@ -0,0 +1,24 @@
+package com.avaje.tests.model.onetoone;
+
+import com.avaje.tests.model.basic.BasicDomain;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Entity;
+import javax.persistence.JoinColumn;
+import javax.persistence.OneToOne;
+
+@Entity
+public class ORoadShowMsg extends BasicDomain {
+
+  @OneToOne(cascade = CascadeType.ALL, optional = false)
+  @JoinColumn()//(name = "corp_id", nullable = false, referencedColumnName = "corp_id")
+  public OCompany company;
+
+  public OCompany getCompany() {
+    return company;
+  }
+
+  public void setCompany(OCompany company) {
+    this.company = company;
+  }
+}

src/test/java/com/avaje/tests/model/onetoone/TestOneToOneJoinColumn.java

@@ -0,0 +1,20 @@
+package com.avaje.tests.model.onetoone;
+
+import com.avaje.ebean.BaseTestCase;
+import com.avaje.ebean.Ebean;
+import org.junit.Test;
+
+public class TestOneToOneJoinColumn extends BaseTestCase {
+
+  @Test
+  public void test() {
+
+    ORoadShowMsg msg = new ORoadShowMsg();
+    OCompany company = new OCompany();
+    company.setCorpId("corp_id_1000000");
+    msg.setCompany(company);
+
+    Ebean.save(msg);
+    Ebean.find(ORoadShowMsg.class, msg.getId());
+  }
+}