Add Mapping for General Insert and Update that Renders null Values More Simply

CHANGELOG.md

@@ -97,6 +97,7 @@ Kotlin DSL.
 - Added support for the "exists" and "not exists" operator in where clauses ([#296](https://github.com/mybatis/mybatis-dynamic-sql/pull/296))
 - Refactored the built-in conditions ([#331](https://github.com/mybatis/mybatis-dynamic-sql/pull/331)) ([#336](https://github.com/mybatis/mybatis-dynamic-sql/pull/336))
 - Added composition functions for WhereApplier ([#335](https://github.com/mybatis/mybatis-dynamic-sql/pull/335))
+- Added a mapping for general insert and update statements that will render null values as "null" in the SQL ([#343](https://github.com/mybatis/mybatis-dynamic-sql/pull/343))
 
 ## Release 1.2.1 - September 29, 2020
 

src/main/java/org/mybatis/dynamic/sql/insert/GeneralInsertDSL.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2021 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -29,6 +29,7 @@
 import org.mybatis.dynamic.sql.util.NullMapping;
 import org.mybatis.dynamic.sql.util.StringConstantMapping;
 import org.mybatis.dynamic.sql.util.ValueMapping;
+import org.mybatis.dynamic.sql.util.ValueOrNullMapping;
 import org.mybatis.dynamic.sql.util.ValueWhenPresentMapping;
 
 public class GeneralInsertDSL implements Buildable<GeneralInsertModel> {
@@ -88,6 +89,15 @@ public GeneralInsertDSL toValue(Supplier<T> valueSupplier) {
             return GeneralInsertDSL.this;
         }
 
+        public GeneralInsertDSL toValueOrNull(T value) {
+            return toValueOrNull(() -> value);
+        }
+
+        public GeneralInsertDSL toValueOrNull(Supplier<T> valueSupplier) {
+            insertMappings.add(ValueOrNullMapping.of(column, valueSupplier));
+            return GeneralInsertDSL.this;
+        }
+
         public GeneralInsertDSL toValueWhenPresent(T value) {
             return toValueWhenPresent(() -> value);
         }

src/main/java/org/mybatis/dynamic/sql/insert/render/GeneralInsertValuePhraseVisitor.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2021 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -26,6 +26,7 @@
 import org.mybatis.dynamic.sql.util.NullMapping;
 import org.mybatis.dynamic.sql.util.StringConstantMapping;
 import org.mybatis.dynamic.sql.util.ValueMapping;
+import org.mybatis.dynamic.sql.util.ValueOrNullMapping;
 import org.mybatis.dynamic.sql.util.ValueWhenPresentMapping;
 
 public class GeneralInsertValuePhraseVisitor extends GeneralInsertMappingVisitor<Optional<FieldAndValueAndParameters>> {
@@ -39,9 +40,7 @@ public GeneralInsertValuePhraseVisitor(RenderingStrategy renderingStrategy) {
 
     @Override
     public Optional<FieldAndValueAndParameters> visit(NullMapping mapping) {
-        return FieldAndValueAndParameters.withFieldName(mapping.columnName())
-                .withValuePhrase("null") //$NON-NLS-1$
-                .buildOptional();
+        return buildNullFragment(mapping);
     }
 
     @Override
@@ -63,6 +62,12 @@ public <T> Optional<FieldAndValueAndParameters> visit(ValueMapping<T> mapping) {
         return buildValueFragment(mapping, mapping.value());
     }
 
+    @Override
+    public <T> Optional<FieldAndValueAndParameters> visit(ValueOrNullMapping<T> mapping) {
+        return mapping.value().map(v -> buildValueFragment(mapping, v))
+                .orElseGet(() -> buildNullFragment(mapping));
+    }
+
     @Override
     public <T> Optional<FieldAndValueAndParameters> visit(ValueWhenPresentMapping<T> mapping) {
         return mapping.value().flatMap(v -> buildValueFragment(mapping, v));
@@ -73,6 +78,12 @@ private Optional<FieldAndValueAndParameters> buildValueFragment(AbstractColumnMa
         return buildFragment(mapping, value);
     }
 
+    private Optional<FieldAndValueAndParameters> buildNullFragment(AbstractColumnMapping mapping) {
+        return FieldAndValueAndParameters.withFieldName(mapping.columnName())
+                .withValuePhrase("null") //$NON-NLS-1$
+                .buildOptional();
+    }
+
     private Optional<FieldAndValueAndParameters> buildFragment(AbstractColumnMapping mapping, Object value) {
         String mapKey = RenderingStrategy.formatParameterMapKey(sequence);
 

src/main/java/org/mybatis/dynamic/sql/update/UpdateDSL.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2021 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -34,6 +34,7 @@
 import org.mybatis.dynamic.sql.util.SelectMapping;
 import org.mybatis.dynamic.sql.util.StringConstantMapping;
 import org.mybatis.dynamic.sql.util.ValueMapping;
+import org.mybatis.dynamic.sql.util.ValueOrNullMapping;
 import org.mybatis.dynamic.sql.util.ValueWhenPresentMapping;
 import org.mybatis.dynamic.sql.where.AbstractWhereDSL;
 import org.mybatis.dynamic.sql.where.AbstractWhereSupport;
@@ -126,6 +127,15 @@ public UpdateDSL<R> equalTo(BasicColumn rightColumn) {
             return UpdateDSL.this;
         }
 
+        public UpdateDSL<R> equalToOrNull(T value) {
+            return equalToOrNull(() -> value);
+        }
+
+        public UpdateDSL<R> equalToOrNull(Supplier<T> valueSupplier) {
+            columnMappings.add(ValueOrNullMapping.of(column, valueSupplier));
+            return UpdateDSL.this;
+        }
+
         public UpdateDSL<R> equalToWhenPresent(T value) {
             return equalToWhenPresent(() -> value);
         }

src/main/java/org/mybatis/dynamic/sql/update/render/SetPhraseVisitor.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2021 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -33,6 +33,7 @@
 import org.mybatis.dynamic.sql.util.StringConstantMapping;
 import org.mybatis.dynamic.sql.util.UpdateMappingVisitor;
 import org.mybatis.dynamic.sql.util.ValueMapping;
+import org.mybatis.dynamic.sql.util.ValueOrNullMapping;
 import org.mybatis.dynamic.sql.util.ValueWhenPresentMapping;
 
 public class SetPhraseVisitor extends UpdateMappingVisitor<Optional<FragmentAndParameters>> {
@@ -74,6 +75,16 @@ public <T> Optional<FragmentAndParameters> visit(ValueMapping<T> mapping) {
         return buildFragment(mapping, mapping.value());
     }
 
+    @Override
+    public <T> Optional<FragmentAndParameters> visit(ValueOrNullMapping<T> mapping) {
+        return mapping.value()
+                .map(v -> buildFragment(mapping, v))
+                .orElseGet(() -> FragmentAndParameters
+                        .withFragment(mapping.columnName() + " = null") //$NON-NLS-1$
+                        .buildOptional()
+                );
+    }
+
     @Override
     public <T> Optional<FragmentAndParameters> visit(ValueWhenPresentMapping<T> mapping) {
         return mapping.value().flatMap(v -> buildFragment(mapping, v));

src/main/java/org/mybatis/dynamic/sql/util/ColumnMappingVisitor.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2021 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -38,6 +38,8 @@ public interface ColumnMappingVisitor<R> {
 
     <T> R visit(ValueMapping<T> mapping);
 
+    <T> R visit(ValueOrNullMapping<T> mapping);
+
     <T> R visit(ValueWhenPresentMapping<T> mapping);
 
     R visit(SelectMapping mapping);

src/main/java/org/mybatis/dynamic/sql/util/InsertMappingVisitor.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2021 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -21,6 +21,11 @@ public final <T> R visit(ValueMapping<T> mapping) {
         throw new UnsupportedOperationException();
     }
 
+    @Override
+    public final <T> R visit(ValueOrNullMapping<T> mapping) {
+        throw new UnsupportedOperationException();
+    }
+
     @Override
     public final <T> R visit(ValueWhenPresentMapping<T> mapping) {
         throw new UnsupportedOperationException();

src/main/java/org/mybatis/dynamic/sql/util/ValueOrNullMapping.java

@@ -0,0 +1,48 @@
+/*
+ *    Copyright 2016-2021 the original author or authors.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+package org.mybatis.dynamic.sql.util;
+
+import java.util.Objects;
+import java.util.Optional;
+import java.util.function.Supplier;
+
+import org.mybatis.dynamic.sql.SqlColumn;
+
+public class ValueOrNullMapping<T> extends AbstractColumnMapping {
+
+    private final Supplier<T> valueSupplier;
+    // keep a reference to the column so we don't lose the type
+    private final SqlColumn<T> localColumn;
+
+    private ValueOrNullMapping(SqlColumn<T> column, Supplier<T> valueSupplier) {
+        super(column);
+        this.valueSupplier = Objects.requireNonNull(valueSupplier);
+        localColumn = Objects.requireNonNull(column);
+    }
+
+    public Optional<Object> value() {
+        return Optional.ofNullable(localColumn.convertParameterType(valueSupplier.get()));
+    }
+
+    @Override
+    public <R> R accept(ColumnMappingVisitor<R> visitor) {
+        return visitor.visit(this);
+    }
+
+    public static <T> ValueOrNullMapping<T> of(SqlColumn<T> column, Supplier<T> valueSupplier) {
+        return new ValueOrNullMapping<>(column, valueSupplier);
+    }
+}

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

@@ -1406,6 +1406,46 @@ void testUpdate() {
         }
     }
 
+    @Test
+    void testUpdateValueOrNullWithValue() {
+        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+            AnimalDataMapper mapper = sqlSession.getMapper(AnimalDataMapper.class);
+            AnimalData record = new AnimalData();
+            record.setBodyWeight(2.6);
+
+            UpdateStatementProvider updateStatement = update(animalData)
+                    .set(animalName).equalToOrNull("fred")
+                    .where(id, isEqualTo(1))
+                    .build()
+                    .render(RenderingStrategies.MYBATIS3);
+
+            assertThat(updateStatement.getUpdateStatement()).isEqualTo(
+                    "update AnimalData set animal_name = #{parameters.p1,jdbcType=VARCHAR} where id = #{parameters.p2,jdbcType=INTEGER}");
+            int rows = mapper.update(updateStatement);
+            assertThat(rows).isEqualTo(1);
+        }
+    }
+
+    @Test
+    void testUpdateValueOrNullWithNull() {
+        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+            AnimalDataMapper mapper = sqlSession.getMapper(AnimalDataMapper.class);
+            AnimalData record = new AnimalData();
+            record.setBodyWeight(2.6);
+
+            UpdateStatementProvider updateStatement = update(animalData)
+                    .set(animalName).equalToOrNull((String) null)
+                    .where(id, isEqualTo(1))
+                    .build()
+                    .render(RenderingStrategies.MYBATIS3);
+
+            assertThat(updateStatement.getUpdateStatement()).isEqualTo(
+                    "update AnimalData set animal_name = null where id = #{parameters.p1,jdbcType=INTEGER}");
+            int rows = mapper.update(updateStatement);
+            assertThat(rows).isEqualTo(1);
+        }
+    }
+
     @Test
     void testInsert() {
         try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
@@ -1994,6 +2034,61 @@ void testGeneralInsert() {
         }
     }
 
+    @Test
+    void testGeneralInsertValueOrNullWithValue() {
+        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+            AnimalDataMapper mapper = sqlSession.getMapper(AnimalDataMapper.class);
+
+            GeneralInsertStatementProvider insertStatement = insertInto(animalData)
+                    .set(id).toValue(101)
+                    .set(animalName).toValueOrNull("Fred")
+                    .set(brainWeight).toConstant("2.2")
+                    .set(bodyWeight).toValue(4.5)
+                    .build()
+                    .render(RenderingStrategies.MYBATIS3);
+
+            String expected = "insert into AnimalData (id, animal_name, brain_weight, body_weight) "
+                    + "values (#{parameters.p1,jdbcType=INTEGER}, #{parameters.p2,jdbcType=VARCHAR}, 2.2, "
+                    + "#{parameters.p3,jdbcType=DOUBLE})";
+
+            assertThat(insertStatement.getInsertStatement()).isEqualTo(expected);
+            assertThat(insertStatement.getParameters()).hasSize(3);
+            assertThat(insertStatement.getParameters()).containsEntry("p1", 101);
+            assertThat(insertStatement.getParameters()).containsEntry("p2", "Fred");
+            assertThat(insertStatement.getParameters()).containsEntry("p3", 4.5);
+
+            int rows = mapper.generalInsert(insertStatement);
+            assertThat(rows).isEqualTo(1);
+        }
+    }
+
+    @Test
+    void testGeneralInsertValueOrNullWithNull() {
+        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+            AnimalDataMapper mapper = sqlSession.getMapper(AnimalDataMapper.class);
+
+            GeneralInsertStatementProvider insertStatement = insertInto(animalData)
+                    .set(id).toValue(101)
+                    .set(animalName).toValueOrNull((String) null)
+                    .set(brainWeight).toConstant("2.2")
+                    .set(bodyWeight).toValue(4.5)
+                    .build()
+                    .render(RenderingStrategies.MYBATIS3);
+
+            String expected = "insert into AnimalData (id, animal_name, brain_weight, body_weight) "
+                    + "values (#{parameters.p1,jdbcType=INTEGER}, null, 2.2, "
+                    + "#{parameters.p2,jdbcType=DOUBLE})";
+
+            assertThat(insertStatement.getInsertStatement()).isEqualTo(expected);
+            assertThat(insertStatement.getParameters()).hasSize(2);
+            assertThat(insertStatement.getParameters()).containsEntry("p1", 101);
+            assertThat(insertStatement.getParameters()).containsEntry("p2", 4.5);
+
+            int rows = mapper.generalInsert(insertStatement);
+            assertThat(rows).isEqualTo(1);
+        }
+    }
+
     @Test
     void testUpdateWithSelect() {
         try (SqlSession sqlSession = sqlSessionFactory.openSession()) {