diff --git a/src/main/java/io/ebeaninternal/server/core/PersistRequestBean.java b/src/main/java/io/ebeaninternal/server/core/PersistRequestBean.java
index e9ee824cf..b36ecbf5a 100644
--- a/src/main/java/io/ebeaninternal/server/core/PersistRequestBean.java
+++ b/src/main/java/io/ebeaninternal/server/core/PersistRequestBean.java
@@ -31,6 +31,7 @@ import io.ebeanservice.docstore.api.DocStoreUpdates;
 import javax.persistence.OptimisticLockException;
 import javax.persistence.PersistenceException;
 import java.io.IOException;
+import java.sql.Statement;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -784,8 +785,12 @@ public final class PersistRequestBean<T> extends PersistRequest implements BeanP
   @Override
   public final void checkRowCount(int rowCount) {
     if (ConcurrencyMode.VERSION == concurrencyMode && rowCount != 1) {
-      String m = Message.msg("persist.conc2", String.valueOf(rowCount));
-      throw new OptimisticLockException(m, null, bean);
+      // fix for oracle.
+      // see: https://stackoverflow.com/questions/19022175/executebatch-method-return-array-of-value-2-in-java
+      if (rowCount != Statement.SUCCESS_NO_INFO) {
+        String m = Message.msg("persist.conc2", String.valueOf(rowCount));
+        throw new OptimisticLockException(m, null, bean);
+      }
     }
     switch (type) {
       case DELETE:
diff --git a/src/main/java/io/ebeaninternal/server/type/ScalarTypeJsonObjectMapper.java b/src/main/java/io/ebeaninternal/server/type/ScalarTypeJsonObjectMapper.java
index fa2e61837..eda46122a 100644
--- a/src/main/java/io/ebeaninternal/server/type/ScalarTypeJsonObjectMapper.java
+++ b/src/main/java/io/ebeaninternal/server/type/ScalarTypeJsonObjectMapper.java
@@ -184,7 +184,7 @@ public class ScalarTypeJsonObjectMapper {
         bind.setObject(PostgresHelper.asObject(pgType, rawJson));
       } else {
         if (value == null) {
-          bind.setNull(Types.LONGNVARCHAR); // use longvarchar, otherwise SqlServer will fail with 'Invalid JDBC data type 5.001.'
+          bind.setNull(Types.VARCHAR); // use varchar, otherwise SqlServer/db2 will fail with 'Invalid JDBC data type 5.001.'
         } else {
           try {
             String json = objectMapper.writeValueAsString(value);
diff --git a/src/test/java/io/ebean/SqlRowBooleanTest.java b/src/test/java/io/ebean/SqlRowBooleanTest.java
index e1edbdb55..3496b02cd 100644
--- a/src/test/java/io/ebean/SqlRowBooleanTest.java
+++ b/src/test/java/io/ebean/SqlRowBooleanTest.java
@@ -14,6 +14,8 @@ public class SqlRowBooleanTest extends BaseTestCase {
       sqlQuery = Ebean.createSqlQuery("SELECT 1 AS ISNT_NULL");
     } else if (isOracle()) {
       sqlQuery = Ebean.createSqlQuery("SELECT 1 AS ISNT_NULL from dual");
+    } else if (isDb2()) {
+      sqlQuery = Ebean.createSqlQuery("SELECT 1 AS ISNT_NULL from SYSIBM.SYSDUMMY1");
     } else {
       sqlQuery = Ebean.createSqlQuery("SELECT 1 IS NOT NULL AS ISNT_NULL");
     }