#3125 Add query.usingMaster() for query beans

ebean-querybean/src/main/java/io/ebean/typequery/TQRootBean.java

@@ -12,6 +12,7 @@ import io.ebean.text.PathProperties;
 import io.ebeaninternal.api.SpiQueryFetch;
 import io.ebeaninternal.server.util.ArrayStack;
 
+import javax.sql.DataSource;
 import java.sql.Connection;
 import java.sql.Timestamp;
 import java.util.*;
@@ -1560,6 +1561,21 @@ public abstract class TQRootBean<T, R> {
     return root;
   }
 
+  /**
+   * Ensure that the master DataSource is used if there is a read only data source
+   * being used (that is using a read replica database potentially with replication lag).
+   * <p>
+   * When the database is configured with a read-only DataSource via
+   * say {@link io.ebean.config.DatabaseConfig#setReadOnlyDataSource(DataSource)} then
+   * by default when a query is run without an active transaction, it uses the read-only data
+   * source. We we use {@code usingMaster()} to instead ensure that the query is executed
+   * against the master data source.
+   */
+  public R usingMaster() {
+    query.usingMaster();
+    return root;
+  }
+
   /**
    * Execute the query returning true if a row is found.
    * <p>

ebean-querybean/src/test/java/org/querytest/QCustomerTest.java

@@ -276,8 +276,15 @@ public class QCustomerTest {
   }
 
   @Test
-  public void usingTransaction() {
+  public void usingMaster() {
+      new QCustomer()
+        .registered.isNull()
+        .usingMaster()
+        .findList();
+  }
 
+  @Test
+  public void usingTransaction() {
     try (Transaction transaction = DB.getDefault().createTransaction()) {
 
       new QCustomer()