Merge pull request #831 from jeffgbutler/column-hierarchy-refactoring

Allow Case Expressions in the Sum Function

Author: jeffgbutler

CHANGELOG.md

@@ -4,11 +4,25 @@ This log will detail notable changes to MyBatis Dynamic SQL. Full details are av
 
 ## Release 2.0.0 - Unreleased
 
-Significant changes:
+Release 2.0.0 is a significant milestone for the library. We have moved to Java 17 as the minimum version supported. If
+you are unable to move to this version of Java then the releases in the 1.x line can be used with Java 8.
+
+In addition, we have taken the opportunity to make changes to the library that may break existing code. We have
+worked to make these changes as minimal as possible.
+
+**Potentially Breaking Changes:**
+
+- If you have implemented any custom functions, you will likely need to make changes. The supplied base classes now
+  hold an instance of `BasicColumn` rather than `BindableColumn`. This change was made to make the functions more
+  useful in variety of circumstances. If you follow the patterns shown on the
+  [Extending the Library](https://mybatis.org/mybatis-dynamic-sql/docs/extending.html) page, the change should be
+  limited to changing the private constructor to accept `BasicColumn` rather than `BindableColumn`.
+
+Other important changes:
 
 - The library now requires Java 17
 - Deprecated code from prior releases is removed
-- Allow CASE expressions in ORDER BY Clauses
+- We now allow CASE expressions in ORDER BY Clauses
 
 ## Release 1.5.2 - June 3, 2024
 

pom.xml

@@ -68,7 +68,9 @@
     <module.name>org.mybatis.dynamic.sql</module.name>
 
     <kotlin.version>2.0.10</kotlin.version>
-    <kotlin.compiler.jvmTarget>1.8</kotlin.compiler.jvmTarget>
+    <kotlin.compiler.jvmTarget>17</kotlin.compiler.jvmTarget>
+    <kotlin.compiler.languageVersion>2.0</kotlin.compiler.languageVersion>
+    <kotlin.compiler.apiVersion>2.0</kotlin.compiler.apiVersion>
 
     <sonar.sources>pom.xml,src/main/java,src/main/kotlin</sonar.sources>
     <sonar.tests>src/test/java,src/test/kotlin</sonar.tests>

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

@@ -15,9 +15,11 @@
  */
 package org.mybatis.dynamic.sql;
 
+import java.sql.JDBCType;
 import java.util.Optional;
 
 import org.mybatis.dynamic.sql.render.RenderingContext;
+import org.mybatis.dynamic.sql.render.RenderingStrategy;
 import org.mybatis.dynamic.sql.util.FragmentAndParameters;
 
 /**
@@ -58,6 +60,18 @@ public interface BasicColumn {
      */
     FragmentAndParameters render(RenderingContext renderingContext);
 
+    default Optional<JDBCType> jdbcType() {
+        return Optional.empty();
+    }
+
+    default Optional<String> typeHandler() {
+        return Optional.empty();
+    }
+
+    default Optional<RenderingStrategy> renderingStrategy() {
+        return Optional.empty();
+    }
+
     /**
      * Utility method to make it easier to build column lists for methods that require an
      * array rather than the varargs method.

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

@@ -15,14 +15,11 @@
  */
 package org.mybatis.dynamic.sql;
 
-import java.sql.JDBCType;
 import java.util.Optional;
 
-import org.mybatis.dynamic.sql.render.RenderingStrategy;
-
 /**
- * Describes additional attributes of columns that are necessary for binding the column as a JDBC parameter.
- * Columns in where clauses are typically bound.
+ * Describes a column with a known data type. The type is only used by the compiler to assure type safety
+ * when building clauses with conditions.
  *
  * @author Jeff Butler
  *
@@ -37,18 +34,6 @@ public interface BindableColumn<T> extends BasicColumn {
     @Override
     BindableColumn<T> as(String alias);
 
-    default Optional<JDBCType> jdbcType() {
-        return Optional.empty();
-    }
-
-    default Optional<String> typeHandler() {
-        return Optional.empty();
-    }
-
-    default Optional<RenderingStrategy> renderingStrategy() {
-        return Optional.empty();
-    }
-
     default Object convertParameterType(T value) {
         return value;
     }

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

@@ -497,6 +497,10 @@ static <T> Sum<T> sum(BindableColumn<T> column) {
         return Sum.of(column);
     }
 
+    static Sum<Object> sum(BasicColumn column) {
+        return Sum.of(column);
+    }
+
     static <T> Sum<T> sum(BindableColumn<T> column, VisitableCondition<T> condition) {
         return Sum.of(column, condition);
     }

src/main/java/org/mybatis/dynamic/sql/select/aggregate/Avg.java

@@ -15,14 +15,15 @@
  */
 package org.mybatis.dynamic.sql.select.aggregate;
 
+import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.BindableColumn;
 import org.mybatis.dynamic.sql.render.RenderingContext;
 import org.mybatis.dynamic.sql.select.function.AbstractUniTypeFunction;
 import org.mybatis.dynamic.sql.util.FragmentAndParameters;
 
 public class Avg<T> extends AbstractUniTypeFunction<T, Avg<T>> {
 
-    private Avg(BindableColumn<T> column) {
+    private Avg(BasicColumn column) {
         super(column);
     }
 

src/main/java/org/mybatis/dynamic/sql/select/aggregate/Max.java

@@ -15,14 +15,15 @@
  */
 package org.mybatis.dynamic.sql.select.aggregate;
 
+import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.BindableColumn;
 import org.mybatis.dynamic.sql.render.RenderingContext;
 import org.mybatis.dynamic.sql.select.function.AbstractUniTypeFunction;
 import org.mybatis.dynamic.sql.util.FragmentAndParameters;
 
 public class Max<T> extends AbstractUniTypeFunction<T, Max<T>> {
 
-    private Max(BindableColumn<T> column) {
+    private Max(BasicColumn column) {
         super(column);
     }
 

src/main/java/org/mybatis/dynamic/sql/select/aggregate/Min.java

@@ -15,14 +15,15 @@
  */
 package org.mybatis.dynamic.sql.select.aggregate;
 
+import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.BindableColumn;
 import org.mybatis.dynamic.sql.render.RenderingContext;
 import org.mybatis.dynamic.sql.select.function.AbstractUniTypeFunction;
 import org.mybatis.dynamic.sql.util.FragmentAndParameters;
 
 public class Min<T> extends AbstractUniTypeFunction<T, Min<T>> {
 
-    private Min(BindableColumn<T> column) {
+    private Min(BasicColumn column) {
         super(column);
     }
 

src/main/java/org/mybatis/dynamic/sql/select/aggregate/Sum.java

@@ -17,6 +17,7 @@
 
 import java.util.function.Function;
 
+import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.BindableColumn;
 import org.mybatis.dynamic.sql.VisitableCondition;
 import org.mybatis.dynamic.sql.render.RenderingContext;
@@ -28,7 +29,7 @@
 public class Sum<T> extends AbstractUniTypeFunction<T, Sum<T>> {
     private final Function<RenderingContext, FragmentAndParameters> renderer;
 
-    private Sum(BindableColumn<T> column) {
+    private Sum(BasicColumn column) {
         super(column);
         renderer = rc -> column.render(rc).mapFragment(this::applyAggregate);
     }
@@ -48,7 +49,7 @@ private Sum(BindableColumn<T> column, VisitableCondition<T> condition) {
         };
     }
 
-    private Sum(BindableColumn<T> column, Function<RenderingContext, FragmentAndParameters> renderer) {
+    private Sum(BasicColumn column, Function<RenderingContext, FragmentAndParameters> renderer) {
         super(column);
         this.renderer = renderer;
     }
@@ -71,6 +72,10 @@ public static <T> Sum<T> of(BindableColumn<T> column) {
         return new Sum<>(column);
     }
 
+    public static Sum<Object> of(BasicColumn column) {
+        return new Sum<>(column);
+    }
+
     public static <T> Sum<T> of(BindableColumn<T> column, VisitableCondition<T> condition) {
         return new Sum<>(column, condition);
     }

src/main/java/org/mybatis/dynamic/sql/select/function/AbstractTypeConvertingFunction.java

@@ -18,6 +18,7 @@
 import java.util.Objects;
 import java.util.Optional;
 
+import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.BindableColumn;
 
 /**
@@ -36,10 +37,10 @@
  */
 public abstract class AbstractTypeConvertingFunction<T, R, U extends AbstractTypeConvertingFunction<T, R, U>>
         implements BindableColumn<R> {
-    protected final BindableColumn<T> column;
+    protected final BasicColumn column;
     protected String alias;
 
-    protected AbstractTypeConvertingFunction(BindableColumn<T> column) {
+    protected AbstractTypeConvertingFunction(BasicColumn column) {
         this.column = Objects.requireNonNull(column);
     }