Fix for #85 - Invalid query when ORDER BY with DISTINCT

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

@@ -305,6 +305,8 @@ public class CQueryBuilder implements Constants {
 
     StringBuilder sb = new StringBuilder(500);
 
+    String dbOrderBy = predicates.getDbOrderBy();
+    
     if (selectClause != null) {
       sb.append(selectClause);
 
@@ -320,6 +322,10 @@ public class CQueryBuilder implements Constants {
       }
 
       sb.append(select.getSelectSql());
+      if (query.isDistinct() && dbOrderBy != null) {
+        // add the orderby columns to the select clause (due to distinct)
+        sb.append(", ").append(convertDbOrderByForSelect(dbOrderBy));
+      }
     }
 
     sb.append(" from ");
@@ -375,7 +381,7 @@ public class CQueryBuilder implements Constants {
       sb.append(dbFilterMany);
     }
 
-    String dbOrderBy = predicates.getDbOrderBy();
+    
     if (dbOrderBy != null) {
       sb.append(" order by ").append(dbOrderBy);
     }
@@ -386,12 +392,20 @@ public class CQueryBuilder implements Constants {
       return sqlLimiter.limit(r);
 
     } else {
-
       return new SqlLimitResponse(dbPlatform.completeSql(sb.toString(), query), false);
     }
 
   }
 
+  /**
+   * Convert the dbOrderBy clause to be safe for adding to select. This is done when 'distinct' is
+   * used.
+   */
+  private String convertDbOrderByForSelect(String dbOrderBy) {
+    // just remove the ASC and DESC keywords
+    return dbOrderBy.replaceAll("(?i)\\b asc\\b|\\b desc\\b", "");
+  }
+  
   private boolean isEmpty(String s) {
     return s == null || s.length() == 0;
   }

src/test/java/com/avaje/tests/query/orderby/TestOrderByWithDistinctTake2.java

@@ -0,0 +1,65 @@
+package com.avaje.tests.query.orderby;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.avaje.ebean.BaseTestCase;
+import com.avaje.ebean.Ebean;
+import com.avaje.ebean.Query;
+import com.avaje.tests.model.basic.Customer;
+
+public class TestOrderByWithDistinctTake2 extends BaseTestCase {
+
+  @Test
+  public void testRegex() {
+    
+    String test = "helloasc asc ASC desc DESC boodesc desc ASC";
+    
+    test = test.replaceAll("(?i)\\b asc\\b|\\b desc\\b", "");
+    System.out.println(test);
+    Assert.assertEquals("helloasc boodesc", test);
+  }
+  
+  
+  @Test
+  public void test() {
+    
+    Query<Customer> query = Ebean.find(Customer.class)
+      .select("id")
+      .where().ilike("contacts.firstName", "R%")
+      .order("name desc");
+    
+    query.findList();
+    
+    String generatedSql = query.getGeneratedSql();
+    
+    // select distinct t0.id c0, t0.name 
+    // from o_customer t0 join contact u1 on u1.customer_id = t0.id  
+    // where lower(u1.first_name) like ?  
+    // order by t0.name; --bind(r%)
+    
+    Assert.assertTrue("t0.name added to the select clause", generatedSql.contains("select distinct t0.id c0, t0.name"));
+    Assert.assertTrue(generatedSql.contains("order by t0.name desc"));
+    Assert.assertTrue(generatedSql.contains("from o_customer t0 join contact u1 on u1.customer_id = t0.id"));
+    Assert.assertTrue(generatedSql.contains("where lower(u1.first_name) like ?"));
+  }
+  
+  @Test
+  public void testWithAscAndDesc() {
+    
+    Query<Customer> query = Ebean.find(Customer.class)
+      .select("id")
+      .where().ilike("contacts.firstName", "R%")
+      .order("name asc,id desc");
+    
+    query.findList();
+    
+    String generatedSql = query.getGeneratedSql();
+    
+    Assert.assertTrue("t0.name added to the select clause", generatedSql.contains("select distinct t0.id c0, t0.name, t0.id"));
+    Assert.assertTrue(generatedSql.contains("order by t0.name, t0.id desc"));
+    Assert.assertTrue(generatedSql.contains("from o_customer t0 join contact u1 on u1.customer_id = t0.id"));
+    Assert.assertTrue(generatedSql.contains("where lower(u1.first_name) like ?"));
+  }
+  
+}