Optional e-mauk field of the AdHoc page

fineract-provider/src/main/java/org/apache/fineract/adhocquery/service/AdHocDataValidator.java

@@ -80,7 +80,7 @@ public final class AdHocDataValidator {
         baseDataValidator.reset().parameter("tableFields").value(tableFields).notBlank().notExceedingLengthOf(1000);
 
         final String email = this.fromApiJsonHelper.extractStringNamed("email", element);
-        baseDataValidator.reset().parameter("email").value(email).notBlank().notExceedingLengthOf(500);
+        baseDataValidator.reset().parameter("email").value(email).ignoreIfNull().notExceedingLengthOf(500);
 
         final Long reportRunFrequencyCode = this.fromApiJsonHelper.extractLongNamed("reportRunFrequency", element);
         if (reportRunFrequencyCode != null) {
@@ -126,7 +126,7 @@ public final class AdHocDataValidator {
         }
         if (this.fromApiJsonHelper.parameterExists("email", element)) {
             final String email = this.fromApiJsonHelper.extractStringNamed("email", element);
-            baseDataValidator.reset().parameter("email").value(email).notBlank().notExceedingLengthOf(500);
+            baseDataValidator.reset().parameter("email").value(email).ignoreIfNull().notExceedingLengthOf(500);
         }
         if (this.fromApiJsonHelper.parameterExists("reportRunFrequency", element)) {
             final Long reportRunFrequencyCode = this.fromApiJsonHelper.extractLongNamed("reportRunFrequency", element);

fineract-provider/src/main/resources/sql/migrations/core_db/V337__nullable-adhoc-email.sql

@@ -0,0 +1,20 @@
+--
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements. See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership. The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License. You may obtain a copy of the License at
+--
+-- http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied. See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+--
+
+ALTER TABLE m_adhoc MODIFY `email` VARCHAR(500) NULL DEFAULT NULL;