#350 - ENH: Add @History findVersions() query - add default ordering to lower sys period desc

src/main/java/com/avaje/ebeaninternal/server/query/CQueryBuilder.java

@@ -46,10 +46,6 @@ public class CQueryBuilder implements Constants {
 
   private final boolean selectCountWithAlias;
 
-  private final Map<String,String> asOfTableMapping;
-
-  private final String asOfSysPeriod;
-  private final DbHistorySupport dbHistorySupport;
   private final CQueryHistorySupport historySupport;
 
   private final DatabasePlatform dbPlatform;
@@ -57,23 +53,17 @@ public class CQueryBuilder implements Constants {
   /**
    * Create the SqlGenSelect.
    */
-  public CQueryBuilder(DatabasePlatform dbPlatform, Binder binder, Map<String,String> asOfTableMapping, String asOfSysPeriod) {
+  public CQueryBuilder(DatabasePlatform dbPlatform, Binder binder, CQueryHistorySupport historySupport) {
 
+    this.dbPlatform = dbPlatform;
     this.binder = binder;
-    this.asOfTableMapping = asOfTableMapping;
-    this.asOfSysPeriod = asOfSysPeriod;
+    this.historySupport = historySupport;
     this.tableAliasPlaceHolder = dbPlatform.getTableAliasPlaceHolder();
     this.columnAliasPrefix = dbPlatform.getColumnAliasPrefix();
     this.sqlSelectBuilder = new RawSqlSelectClauseBuilder(dbPlatform, binder);
-
-    this.dbHistorySupport = dbPlatform.getHistorySupport();
-    this.historySupport = new CQueryHistorySupport(dbHistorySupport, asOfTableMapping, asOfSysPeriod);
     this.sqlLimiter = dbPlatform.getSqlLimiter();
     this.rawSqlHandler = new CQueryBuilderRawSql(sqlLimiter, dbPlatform);
-
     this.selectCountWithAlias = dbPlatform.isSelectCountWithAlias();
-
-    this.dbPlatform = dbPlatform;
   }
 
   /**
@@ -427,7 +417,7 @@ public class CQueryBuilder implements Constants {
         if (i > 0) {
           sb.append(" and ");
         }
-        sb.append(dbHistorySupport.getAsOfPredicate(asOfTableAlias.get(i), asOfSysPeriod));
+        sb.append(historySupport.getAsOfPredicate(asOfTableAlias.get(i)));
       }
     }
 

src/main/java/com/avaje/ebeaninternal/server/query/CQueryEngine.java

@@ -30,13 +30,18 @@ public class CQueryEngine {
 
   private static final int defaultSecondaryQueryBatchSize = 100;
 
+  private static final String T0 = "t0";
+
   private final boolean forwardOnlyHintOnFindIterate;
 
   private final CQueryBuilder queryBuilder;
 
+  private final CQueryHistorySupport historySupport;
+
   public CQueryEngine(DatabasePlatform dbPlatform, Binder binder, Map<String,String> asOfTableMapping, String asOfSysPeriod) {
     this.forwardOnlyHintOnFindIterate = dbPlatform.isForwardOnlyHintOnFindIterate();
-    this.queryBuilder = new CQueryBuilder(dbPlatform, binder, asOfTableMapping, asOfSysPeriod);
+    this.historySupport = new CQueryHistorySupport(dbPlatform.getHistorySupport(), asOfTableMapping, asOfSysPeriod);
+    this.queryBuilder = new CQueryBuilder(dbPlatform, binder, historySupport);
   }
 
   public <T> CQuery<T> buildQuery(OrmQueryRequest<T> request) {
@@ -161,6 +166,12 @@ public class CQueryEngine {
    */
   public <T> List<Version<T>> findVersions(OrmQueryRequest<T> request) {
 
+    SpiQuery<T> query = request.getQuery();
+
+    // order by id asc, lower sys period desc
+    query.orderBy().asc(request.getBeanDescriptor().getIdProperty().getName());
+    query.orderBy().desc(getSysPeriodLower(query));
+
     CQuery<T> cquery = queryBuilder.buildQuery(request);
     try {
       cquery.prepareBindExecuteQuery();
@@ -185,6 +196,17 @@ public class CQueryEngine {
     }
   }
 
+  /**
+   * Return the lower sys_period given the table alias of the query or default.
+   */
+  private <T> String getSysPeriodLower(SpiQuery<T> query) {
+    String rootTableAlias = query.getAlias();
+    if (rootTableAlias == null) {
+      rootTableAlias = T0;
+    }
+    return historySupport.getSysPeriodLower(rootTableAlias);
+  }
+
   /**
    * Find a list/map/set of beans.
    */

src/main/java/com/avaje/ebeaninternal/server/query/CQueryHistorySupport.java

@@ -22,12 +22,12 @@ public class CQueryHistorySupport {
   /**
    * The sys period column.
    */
-  private final String asOfSysPeriod;
+  private final String sysPeriod;
 
-  public CQueryHistorySupport(DbHistorySupport dbHistorySupport, Map<String, String> asOfTableMap, String asOfSysPeriod) {
+  public CQueryHistorySupport(DbHistorySupport dbHistorySupport, Map<String, String> asOfTableMap, String sysPeriod) {
     this.dbHistorySupport = dbHistorySupport;
     this.asOfTableMap = asOfTableMap;
-    this.asOfSysPeriod = asOfSysPeriod;
+    this.sysPeriod = sysPeriod;
   }
 
   public String getAsOfView(String table) {
@@ -36,12 +36,16 @@ public class CQueryHistorySupport {
 
   public String getSysPeriodLower(String tableAlias) {
 
-    return dbHistorySupport.getSysPeriodLower(tableAlias, asOfSysPeriod);
+    return dbHistorySupport.getSysPeriodLower(tableAlias, sysPeriod);
   }
 
   public String getSysPeriodUpper(String tableAlias) {
 
-    return dbHistorySupport.getSysPeriodUpper(tableAlias, asOfSysPeriod);
+    return dbHistorySupport.getSysPeriodUpper(tableAlias, sysPeriod);
   }
 
+  public String getAsOfPredicate(String tableAlias) {
+
+    return dbHistorySupport.getAsOfPredicate(tableAlias, sysPeriod);
+  }
 }