NEW: CustomDeployParser

ebean-test/src/test/java/org/tests/model/tevent/CustomFormulaAnnotationParser.java

@@ -0,0 +1,61 @@
+package org.tests.model.tevent;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import io.ebean.annotation.Formula;
+import io.ebean.config.dbplatform.DatabasePlatform;
+import io.ebean.plugin.CustomDeployParser;
+import io.ebean.plugin.DeployBeanDescriptorMeta;
+import io.ebean.plugin.DeployBeanPropertyMeta;
+import io.ebean.util.AnnotationUtil;
+import io.ebeaninternal.server.deploy.meta.DeployBeanPropertyAssocMany;
+
+/**
+ * Custom Annotation parser which parses @Count annotation
+ *
+ * @author Roland Praml, FOCONIS AG
+  */
+public class CustomFormulaAnnotationParser implements CustomDeployParser {
+
+  private int counter;
+
+
+  @Target(FIELD)
+  @Retention(RUNTIME)
+  @Formula(select="TODO", join = "TODO") // meta-formula
+  public @interface Count {
+    String value();
+  }
+
+
+
+  @Override
+  public void parse(final DeployBeanDescriptorMeta descriptor, final DatabasePlatform databasePlatform) {
+    for (DeployBeanPropertyMeta prop : descriptor.propertiesAll()) {
+      readField(descriptor, prop);
+    }
+  }
+
+  private void readField(DeployBeanDescriptorMeta descriptor, DeployBeanPropertyMeta prop) {
+   Count countAnnot = AnnotationUtil.get(prop.getField(), Count.class);
+    if (countAnnot != null) {
+      // @Count found, so build the (complex) count formula
+      DeployBeanPropertyAssocMany<?> countProp =  (DeployBeanPropertyAssocMany<?>) descriptor.getBeanProperty(countAnnot.value());
+      counter++;
+      String tmpTable = "f"+counter;
+      String sqlSelect = "coalesce(" + tmpTable + ".child_count, 0)";
+      String parentId = countProp.getMappedBy() + "_id";
+      String tableName = countProp.getBeanTable().getBaseTable();
+      String sqlJoin = "left join (select " + parentId +", count(*) as child_count from " + tableName + " GROUP BY " + parentId + " )"
+          + " " + tmpTable + " on " + tmpTable + "." +parentId + " = ${ta}." + descriptor.idProperty().getDbColumn();
+      prop.setSqlFormula(sqlSelect, sqlJoin);
+//      prop.setSqlFormula("f1.child_count",
+//          "join (select parent_id, count(*) as child_count from child_entity GROUP BY parent_id) f1 on f1.parent_id = ${ta}.id");
+    }
+  }
+
+}

ebean-test/src/test/java/org/tests/model/tevent/TEventOne.java

@@ -41,6 +41,11 @@ public class TEventOne {
   @OneToMany(mappedBy = "event", cascade = CascadeType.ALL)
   List<TEventMany> logs;
 
+  @CustomFormulaAnnotationParser.Count("logs")
+  //@Formula(select = "f1.child_count",
+  //join = "left join (select event_id, count(*) as child_count from tevent_many GROUP BY event_id ) as f1 on f1.event_id = ${ta}.id")
+  Long customFormula;
+
   public TEventOne(String name, Status status) {
     this.name = name;
     this.status = status;
@@ -63,6 +68,10 @@ public class TEventOne {
     return count;
   }
 
+  public Long getCustomFormula() {
+    return customFormula;
+  }
+
   public Double getTotalUnits() {
     return totalUnits;
   }

ebean-test/src/test/java/org/tests/query/aggregation/TestAggregationCount.java

@@ -48,7 +48,7 @@ public class TestAggregationCount extends BaseTestCase {
     List<TEventOne> list = query.findList();
 
     String sql = sqlOf(query, 5);
-    assertThat(sql).contains("select t0.id, t0.name, t0.status, t0.version, t0.event_id from tevent_one t0");
+    assertThat(sql).contains("select t0.id, t0.name, t0.status, coalesce(f1.child_count, 0), t0.version, t0.event_id from tevent_one t0");
 
     for (TEventOne eventOne : list) {
       // lazy loading on Aggregation properties