#1405 - ENH: Add SqlQuery.findSingleAttribute() ... for returning single scalar values via SqlQuery

src/test/java/io/ebeaninternal/api/TDSpiEbeanServer.java

@@ -457,6 +457,11 @@ public class TDSpiEbeanServer implements SpiEbeanServer {
     return null;
   }
 
+  @Override
+  public <T> T findSingleAttribute(SpiSqlQuery query, Class<T> cls) {
+    return null;
+  }
+
   @Override
   public SqlQuery createSqlQuery(String sql) {
     return null;

src/test/java/org/tests/basic/type/TestSqlRowUUID.java

@@ -5,11 +5,14 @@ import io.ebean.Ebean;
 import io.ebean.SqlQuery;
 import io.ebean.SqlRow;
 import org.tests.model.basic.TUuidEntity;
-import org.junit.Assert;
 import org.junit.Test;
 
 import java.util.UUID;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+
 public class TestSqlRowUUID extends BaseTestCase {
 
   @Test
@@ -26,9 +29,17 @@ public class TestSqlRowUUID extends BaseTestCase {
 
     UUID id = sqlRow.getUUID("id");
 
-    Assert.assertNotNull(id);
+    assertNotNull(id);
 
     Boolean b = sqlRow.getBoolean("name");
-    Assert.assertFalse(b);
+    assertFalse(b);
+
+
+    SqlQuery q2 = Ebean.createSqlQuery("select id from tuuid_entity where id = :id");
+    q2.setParameter("id", e.getId());
+    UUID value = q2.findSingleAttribute(UUID.class);
+
+    assertThat(value).isEqualTo(e.getId());
+
   }
 }

src/test/java/org/tests/query/sqlquery/SqlQueryTests.java

@@ -10,6 +10,8 @@ import org.junit.Test;
 import org.tests.model.basic.Order;
 import org.tests.model.basic.ResetBasicData;
 
+import java.math.BigDecimal;
+import java.time.OffsetDateTime;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -18,6 +20,49 @@ import static org.junit.Assert.assertEquals;
 
 public class SqlQueryTests extends BaseTestCase {
 
+  @Test
+  public void findSingleAttribute_decimal() {
+
+    ResetBasicData.reset();
+
+    String sql = "select max(unit_price) from o_order_detail where order_qty > ?";
+
+    BigDecimal maxPrice = Ebean.createSqlQuery(sql)
+      .setParameter(1, 2)
+      .findSingleAttribute(BigDecimal.class);
+
+    assertThat(maxPrice).isNotNull();
+  }
+
+  @Test
+  public void findSingleAttribute_long() {
+
+    ResetBasicData.reset();
+
+    String sql = "select count(order_qty) from o_order_detail where unit_price > ?";
+
+    long count = Ebean.createSqlQuery(sql)
+      .setParameter(1, 2)
+      .findSingleAttribute(Long.class);
+
+    assertThat(count).isGreaterThan(0);
+  }
+
+  @Test
+  public void findSingleAttribute_OffsetDateTime() {
+
+    ResetBasicData.reset();
+
+    String sql = "select min(updtime) from o_order_detail where unit_price > ? and updtime is not null";
+
+    OffsetDateTime minCreated = Ebean.createSqlQuery(sql)
+      .setParameter(1, 2)
+      .findSingleAttribute(OffsetDateTime.class);
+
+    assertThat(minCreated).isBefore(OffsetDateTime.now());
+  }
+
+
   @Test
   public void newline_replacedInLogsOnly() {