Merge pull request #51 from jeffgbutler/master

Add support for Union All

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/select/QueryExpressionDSL.java

@@ -124,7 +124,12 @@ public SelectDSL<R> orderBy(SortSpecification...columns) {
 
     public UnionBuilder union() {
         selectDSL.addQueryExpression(buildModel());
-        return new UnionBuilder();
+        return new UnionBuilder("union"); //$NON-NLS-1$
+    }
+
+    public UnionBuilder unionAll() {
+        selectDSL.addQueryExpression(buildModel());
+        return new UnionBuilder("union all"); //$NON-NLS-1$
     }
 
     protected QueryExpressionModel buildModel() {
@@ -206,7 +211,13 @@ private <T> QueryExpressionWhereBuilder(BindableColumn<T> column, VisitableCondi
         public UnionBuilder union() {
             whereModel = buildWhereModel();
             selectDSL.addQueryExpression(buildModel());
-            return new UnionBuilder();
+            return new UnionBuilder("union"); //$NON-NLS-1$
+        }
+
+        public UnionBuilder unionAll() {
+            whereModel = buildWhereModel();
+            selectDSL.addQueryExpression(buildModel());
+            return new UnionBuilder("union all"); //$NON-NLS-1$
         }
 
         public SelectDSL<R> orderBy(SortSpecification...columns) {
@@ -388,17 +399,23 @@ public R build() {
     }
 
     public class UnionBuilder {
+        private String connector;
+        
+        public UnionBuilder(String connector) {
+            this.connector = Objects.requireNonNull(connector);
+        }
+        
         public FromGatherer<R> select(BasicColumn...selectList) {
             return new FromGathererBuilder<R>()
-                    .withConnector("union") //$NON-NLS-1$
+                    .withConnector(connector)
                     .withSelectList(selectList)
                     .withSelectDSL(selectDSL)
                     .build();
         }
 
         public FromGatherer<R> selectDistinct(BasicColumn...selectList) {
             return new FromGathererBuilder<R>()
-                    .withConnector("union") //$NON-NLS-1$
+                    .withConnector(connector)
                     .isDistinct()
                     .withSelectList(selectList)
                     .withSelectDSL(selectDSL)

src/site/markdown/docs/select.md

@@ -6,7 +6,7 @@ select statements, but purposely does not cover every possibility.
 In general, the following are supported:
 
 1. The typical parts of a select statement including SELECT, DISTINCT, FROM, JOIN, WHERE, GROUP BY, UNION,
-   ORDER BY
+   UNION ALL, ORDER BY
 2. Tables can be aliased per select statement
 3. Columns can be aliased per select statement
 4. Some support for aggregates (avg, min, max, sum)
@@ -70,7 +70,7 @@ The library supports four join types:
 4. `.fullJoin(...)` is a FULL OUTER join
 
 ## Union Queries
-The library supports the generation of UNION queries.  Foe example:
+The library supports the generation of UNION and UNION ALL queries.  For example:
 
 ```java
     SelectStatementProvider selectStatement = select(id, animalName, bodyWeight, brainWeight)

src/test/java/examples/animal/data/AnimalDataTest.java

@@ -287,6 +287,36 @@ public void testUnionSelectWithoutWhere() {
         }
     }
 
+    @Test
+    public void testUnionAllSelectWithoutWhere() {
+        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+            AnimalDataMapper mapper = sqlSession.getMapper(AnimalDataMapper.class);
+            
+            SelectStatementProvider selectStatement = select(id, animalName, bodyWeight, brainWeight)
+                    .from(animalData)
+                    .unionAll()
+                    .selectDistinct(id, animalName, bodyWeight, brainWeight)
+                    .from(animalData)
+                    .orderBy(id)
+                    .build()
+                    .render(RenderingStrategy.MYBATIS3);
+            
+            String expected = "select id, animal_name, body_weight, brain_weight "
+                    + "from AnimalData "
+                    + "union all "
+                    + "select distinct id, animal_name, body_weight, brain_weight "
+                    + "from AnimalData "
+                    + "order by id";
+
+            List<AnimalData> animals = mapper.selectMany(selectStatement);
+            assertAll(
+                    () -> assertThat(selectStatement.getSelectStatement()).isEqualTo(expected),
+                    () -> assertThat(animals.size()).isEqualTo(130),
+                    () -> assertThat(selectStatement.getParameters().size()).isEqualTo(0)
+            );
+        }
+    }
+    
     @Test
     public void testUnionSelectWithTableAliases() {
         try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
@@ -324,6 +354,43 @@ public void testUnionSelectWithTableAliases() {
         }
     }
 
+    @Test
+    public void testUnionAllSelectWithTableAliases() {
+        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+            AnimalDataMapper mapper = sqlSession.getMapper(AnimalDataMapper.class);
+            
+            SelectStatementProvider selectStatement = select(id, animalName, bodyWeight, brainWeight)
+                    .from(animalData, "a")
+                    .where(id, isLessThan(20))
+                    .unionAll()
+                    .select(id, animalName, bodyWeight, brainWeight)
+                    .from(animalData, "b")
+                    .where(id, isGreaterThan(40))
+                    .orderBy(id)
+                    .build()
+                    .render(RenderingStrategy.MYBATIS3);
+            
+            String expected = "select a.id, a.animal_name, a.body_weight, a.brain_weight "
+                    + "from AnimalData a "
+                    + "where a.id < #{parameters.p1,jdbcType=INTEGER} "
+                    + "union all "
+                    + "select b.id, b.animal_name, b.body_weight, b.brain_weight "
+                    + "from AnimalData b "
+                    + "where b.id > #{parameters.p2,jdbcType=INTEGER} "
+                    + "order by id";
+
+            List<AnimalData> animals = mapper.selectMany(selectStatement);
+
+            assertAll(
+                    () -> assertThat(selectStatement.getSelectStatement()).isEqualTo(expected),
+                    () -> assertThat(animals.size()).isEqualTo(44),
+                    () -> assertThat(selectStatement.getParameters().size()).isEqualTo(2),
+                    () -> assertThat(selectStatement.getParameters().get("p1")).isEqualTo(20),
+                    () -> assertThat(selectStatement.getParameters().get("p2")).isEqualTo(40)
+            );
+        }
+    }
+
     @Test
     public void testUnionSelectWithTableAndColumnAliases() {
         try (SqlSession sqlSession = sqlSessionFactory.openSession()) {