Add ability to use a function in an update statement

src/main/java/org/mybatis/dynamic/sql/select/function/Constant.java → src/main/java/org/mybatis/dynamic/sql/Constant.java

@@ -13,20 +13,19 @@
  *    See the License for the specific language governing permissions and
  *    limitations under the License.
  */
-package org.mybatis.dynamic.sql.select.function;
+package org.mybatis.dynamic.sql;
 
 import java.util.Objects;
 import java.util.Optional;
 
-import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.render.TableAliasCalculator;
 
-public class Constant<T> implements BasicColumn {
+public class Constant implements BasicColumn {
 
     private String alias;
-    private T value;
+    private String value;
 
-    private Constant(T value) {
+    private Constant(String value) {
         this.value = Objects.requireNonNull(value);
     }
 
@@ -37,17 +36,17 @@ public Optional<String> alias() {
 
     @Override
     public String renderWithTableAlias(TableAliasCalculator tableAliasCalculator) {
-        return value.toString();
+        return value;
     }
 
     @Override
-    public Constant<T> as(String alias) {
-        Constant<T> copy = new Constant<>(value);
+    public Constant as(String alias) {
+        Constant copy = new Constant(value);
         copy.alias = alias;
         return copy;
     }
 
-    public static <T> Constant<T> of(T value) {
-        return new Constant<>(value);
+    public static Constant of(String value) {
+        return new Constant(value);
     }
 }

src/main/java/org/mybatis/dynamic/sql/SqlBuilder.java

@@ -35,7 +35,6 @@
 import org.mybatis.dynamic.sql.select.aggregate.Min;
 import org.mybatis.dynamic.sql.select.aggregate.Sum;
 import org.mybatis.dynamic.sql.select.function.Add;
-import org.mybatis.dynamic.sql.select.function.Constant;
 import org.mybatis.dynamic.sql.select.function.Divide;
 import org.mybatis.dynamic.sql.select.function.Lower;
 import org.mybatis.dynamic.sql.select.function.Multiply;
@@ -192,12 +191,12 @@ static Sum sum(BasicColumn column) {
     }
 
     // constants
-    static <T extends Number> Constant<T> constant(T number) {
-        return Constant.of(number);
+    static Constant constant(String constant) {
+        return Constant.of(constant);
     }
 
-    static Constant<String> constant(String string) {
-        return Constant.of("'" + string + "'"); //$NON-NLS-1$ //$NON-NLS-2$
+    static StringConstant stringConstant(String constant) {
+        return StringConstant.of(constant);
     }
 
     // functions

src/main/java/org/mybatis/dynamic/sql/StringConstant.java

@@ -0,0 +1,52 @@
+/**
+ *    Copyright 2016-2018 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;
+
+import java.util.Objects;
+import java.util.Optional;
+
+import org.mybatis.dynamic.sql.render.TableAliasCalculator;
+
+public class StringConstant implements BasicColumn {
+
+    private String alias;
+    private String value;
+
+    private StringConstant(String value) {
+        this.value = Objects.requireNonNull(value);
+    }
+
+    @Override
+    public Optional<String> alias() {
+        return Optional.ofNullable(alias);
+    }
+
+    @Override
+    public String renderWithTableAlias(TableAliasCalculator tableAliasCalculator) {
+        return "'" + value + "'"; //$NON-NLS-1$ //$NON-NLS-2$
+    }
+
+    @Override
+    public StringConstant as(String alias) {
+        StringConstant copy = new StringConstant(value);
+        copy.alias = alias;
+        return copy;
+    }
+
+    public static StringConstant of(String value) {
+        return new StringConstant(value);
+    }
+}

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

@@ -21,16 +21,16 @@
 import java.util.function.Function;
 import java.util.function.Supplier;
 
+import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.BindableColumn;
 import org.mybatis.dynamic.sql.SqlColumn;
 import org.mybatis.dynamic.sql.SqlCriterion;
 import org.mybatis.dynamic.sql.SqlTable;
 import org.mybatis.dynamic.sql.VisitableCondition;
 import org.mybatis.dynamic.sql.select.SelectModel;
 import org.mybatis.dynamic.sql.update.render.UpdateStatementProvider;
-import org.mybatis.dynamic.sql.util.ArithmeticConstantMapping;
-import org.mybatis.dynamic.sql.util.ArithmeticOperation;
 import org.mybatis.dynamic.sql.util.Buildable;
+import org.mybatis.dynamic.sql.util.ColumnMapping;
 import org.mybatis.dynamic.sql.util.ConstantMapping;
 import org.mybatis.dynamic.sql.util.NullMapping;
 import org.mybatis.dynamic.sql.util.SelectMapping;
@@ -126,6 +126,11 @@ public UpdateDSL<R> equalTo(Buildable<SelectModel> buildable) {
             return UpdateDSL.this;
         }
 
+        public UpdateDSL<R> equalTo(BasicColumn rightColumn) {
+            columnMappings.add(ColumnMapping.of(column, rightColumn));
+            return UpdateDSL.this;
+        }
+
         public UpdateDSL<R> equalToWhenPresent(T value) {
             return equalToWhenPresent(() -> value);
         }
@@ -136,42 +141,6 @@ public UpdateDSL<R> equalToWhenPresent(Supplier<T> valueSupplier) {
             }
             return UpdateDSL.this;
         }
-
-        public UpdateDSL<R> incrementBy(T value) {
-            return incrementBy(() -> value);
-        }
-
-        public UpdateDSL<R> incrementBy(Supplier<T> valueSupplier) {
-            columnMappings.add(ArithmeticConstantMapping.of(column, ArithmeticOperation.ADD, valueSupplier));
-            return UpdateDSL.this;
-        }
-
-        public UpdateDSL<R> decrementBy(T value) {
-            return decrementBy(() -> value);
-        }
-
-        public UpdateDSL<R> decrementBy(Supplier<T> valueSupplier) {
-            columnMappings.add(ArithmeticConstantMapping.of(column, ArithmeticOperation.SUBTRACT, valueSupplier));
-            return UpdateDSL.this;
-        }
-
-        public UpdateDSL<R> multiplyBy(T value) {
-            return multiplyBy(() -> value);
-        }
-
-        public UpdateDSL<R> multiplyBy(Supplier<T> valueSupplier) {
-            columnMappings.add(ArithmeticConstantMapping.of(column, ArithmeticOperation.MULTIPLY, valueSupplier));
-            return UpdateDSL.this;
-        }
-
-        public UpdateDSL<R> divideBy(T value) {
-            return divideBy(() -> value);
-        }
-
-        public UpdateDSL<R> divideBy(Supplier<T> valueSupplier) {
-            columnMappings.add(ArithmeticConstantMapping.of(column, ArithmeticOperation.DIVIDE, valueSupplier));
-            return UpdateDSL.this;
-        }
     }
 
     public class UpdateWhereBuilder extends AbstractWhereDSL<UpdateWhereBuilder> {

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

@@ -21,9 +21,10 @@
 
 import org.mybatis.dynamic.sql.SqlColumn;
 import org.mybatis.dynamic.sql.render.RenderingStrategy;
+import org.mybatis.dynamic.sql.render.TableAliasCalculator;
 import org.mybatis.dynamic.sql.select.render.SelectRenderer;
 import org.mybatis.dynamic.sql.select.render.SelectStatementProvider;
-import org.mybatis.dynamic.sql.util.ArithmeticConstantMapping;
+import org.mybatis.dynamic.sql.util.ColumnMapping;
 import org.mybatis.dynamic.sql.util.ConstantMapping;
 import org.mybatis.dynamic.sql.util.FragmentAndParameters;
 import org.mybatis.dynamic.sql.util.NullMapping;
@@ -80,19 +81,6 @@ public <T> FragmentAndParameters visit(ValueMapping<T> mapping) {
                 .build();
     }
 
-    @Override
-    public <S> FragmentAndParameters visit(ArithmeticConstantMapping<S> mapping) {
-        String fragment = mapping.mapColumn(SqlColumn::name)
-                + " = " //$NON-NLS-1$
-                + mapping.mapColumn(SqlColumn::name)
-                + " " //$NON-NLS-1$
-                + mapping.operation().getOperator()
-                + " " //$NON-NLS-1$
-                + mapping.valueSupplier().get();
-        return FragmentAndParameters.withFragment(fragment)
-                .build();
-    }
-
     @Override
     public FragmentAndParameters visit(SelectMapping mapping) {
         SelectStatementProvider selectStatement = SelectRenderer.withSelectModel(mapping.selectModel())
@@ -111,6 +99,16 @@ public FragmentAndParameters visit(SelectMapping mapping) {
                 .build();
     }
 
+    @Override
+    public FragmentAndParameters visit(ColumnMapping mapping) {
+        String setPhrase = mapping.mapColumn(SqlColumn::name)
+                + " = "  //$NON-NLS-1$
+                + mapping.rightColumn().renderWithTableAlias(TableAliasCalculator.empty());
+
+        return FragmentAndParameters.withFragment(setPhrase)
+                .build();
+    }
+
     private Function<SqlColumn<?>, String> toJdbcPlaceholder(String parameterName) {
         return column -> renderingStrategy
                 .getFormattedJdbcPlaceholder(column, "parameters", parameterName); //$NON-NLS-1$

src/main/java/org/mybatis/dynamic/sql/util/ArithmeticOperation.java → src/main/java/org/mybatis/dynamic/sql/util/ColumnMapping.java

@@ -15,19 +15,28 @@
  */
 package org.mybatis.dynamic.sql.util;
 
-public enum ArithmeticOperation {
-    ADD("+"), //$NON-NLS-1$
-    SUBTRACT("-"), //$NON-NLS-1$
-    MULTIPLY("*"), //$NON-NLS-1$
-    DIVIDE("/"); //$NON-NLS-1$
+import org.mybatis.dynamic.sql.BasicColumn;
+import org.mybatis.dynamic.sql.SqlColumn;
+
+public class ColumnMapping extends AbstractColumnMapping implements UpdateMapping {
+
+    private BasicColumn rightColumn;
 
-    private String operator;
+    private ColumnMapping(SqlColumn<?> column, BasicColumn rightColumn) {
+        super(column);
+        this.rightColumn = rightColumn;
+    }
 
-    private ArithmeticOperation(String operator) {
-        this.operator = operator;
+    public BasicColumn rightColumn() {
+        return rightColumn;
     }
 
-    public String getOperator() {
-        return operator;
+    @Override
+    public <R> R accept(UpdateMappingVisitor<R> visitor) {
+        return visitor.visit(this);
+    }
+
+    public static ColumnMapping of(SqlColumn<?> column, BasicColumn rightColumn) {
+        return new ColumnMapping(column, rightColumn);
     }
 }

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

@@ -24,7 +24,7 @@ public interface UpdateMappingVisitor<T> {
 
     <S> T visit(ValueMapping<S> mapping);
 
-    <S> T visit(ArithmeticConstantMapping<S> mapping);
-
     T visit(SelectMapping mapping);
+
+    T visit(ColumnMapping columnMapping);
 }

src/site/markdown/docs/update.md

@@ -25,6 +25,7 @@ Notice the `set` method. It is used to set the value of a database column.  Ther
 6. `set(column).equalToWhenPresent(T value)` will set a value into a column if the value is non-null.  The value of the property will be bound to the SQL statement as a prepared statement parameter.  This is used to generate a "selective" update as defined in MyBatis Generator.
 7. `set(column).equalToWhenPresent(Supplier<T> valueSupplier)` will set a value into a column if the value is non-null.  The value of the property will be bound to the SQL statement as a prepared statement parameter.  This is used to generate a "selective" update as defined in MyBatis Generator.
 8. `set(column).equalTo(Buildable<SelectModel> selectModelBuilder)` will set the result of a sub-query into a column.  The query should only have one column and the type of the returned column must be able to be converted by the database if it is not the same type. These constraints are NOT validated by the library.
+9. `set(column).equalTo(BasicColumn rightColumn)` will set the value of a column the be the value of another column.  This is also useful for specifying a function such as add, subtract, etc.
 
 You can also build an update statement without a where clause.  This will update every row in a table.
 For example:

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

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2017 the original author or authors.
+ *    Copyright 2016-2018 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.
@@ -46,6 +46,10 @@ public interface AnimalDataMapper {
     })
     List<AnimalData> selectMany(SelectStatementProvider selectStatement);
 
+    @SelectProvider(type=SqlProviderAdapter.class, method="select")
+    @ResultMap("AnimalDataResult")
+    AnimalData selectOne(SelectStatementProvider selectStatement);
+
     @SelectProvider(type=SqlProviderAdapter.class, method="select")
     List<Map<String, Object>> generalSelect(SelectStatementProvider selectStatement);