Remove some useles abstraction in the count functions

Author: jeffgbutler

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

@@ -26,9 +26,13 @@
  *
  * @param <T> the subtype of this class
  */
-public abstract class AbstractCount<T extends AbstractCount<T>> implements BindableColumn<Long> {
+public abstract class AbstractCount implements BindableColumn<Long> {
     private final String alias;
 
+    protected AbstractCount() {
+        this(null);
+    }
+
     protected AbstractCount(String alias) {
         this.alias = alias;
     }
@@ -37,11 +41,4 @@ protected AbstractCount(String alias) {
     public Optional<String> alias() {
         return Optional.ofNullable(alias);
     }
-
-    @Override
-    public T as(String alias) {
-        return copyWithAlias(alias);
-    }
-
-    protected abstract T copyWithAlias(String alias);
 }

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

@@ -20,10 +20,14 @@
 import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.render.TableAliasCalculator;
 
-public class Count extends AbstractCount<Count> {
+public class Count extends AbstractCount {
 
     private final BasicColumn column;
 
+    private Count(BasicColumn column) {
+        this.column = Objects.requireNonNull(column);
+    }
+
     private Count(BasicColumn column, String alias) {
         super(alias);
         this.column = Objects.requireNonNull(column);
@@ -35,11 +39,11 @@ public String renderWithTableAlias(TableAliasCalculator tableAliasCalculator) {
     }
 
     @Override
-    protected Count copyWithAlias(String alias) {
+    public Count as(String alias) {
         return new Count(column, alias);
     }
 
     public static Count of(BasicColumn column) {
-        return new Count(column, null);
+        return new Count(column);
     }
 }

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

@@ -17,10 +17,10 @@
 
 import org.mybatis.dynamic.sql.render.TableAliasCalculator;
 
-public class CountAll extends AbstractCount<CountAll> {
+public class CountAll extends AbstractCount {
 
     public CountAll() {
-        super(null);
+        super();
     }
 
     private CountAll(String alias) {
@@ -33,7 +33,7 @@ public String renderWithTableAlias(TableAliasCalculator tableAliasCalculator) {
     }
 
     @Override
-    protected CountAll copyWithAlias(String alias) {
+    public CountAll as(String alias) {
         return new CountAll(alias);
     }
 }

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

@@ -20,10 +20,14 @@
 import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.render.TableAliasCalculator;
 
-public class CountDistinct extends AbstractCount<CountDistinct> {
+public class CountDistinct extends AbstractCount {
 
     private final BasicColumn column;
 
+    private CountDistinct(BasicColumn column) {
+        this.column = Objects.requireNonNull(column);
+    }
+
     private CountDistinct(BasicColumn column, String alias) {
         super(alias);
         this.column = Objects.requireNonNull(column);
@@ -35,11 +39,11 @@ public String renderWithTableAlias(TableAliasCalculator tableAliasCalculator) {
     }
 
     @Override
-    public CountDistinct copyWithAlias(String alias) {
+    public CountDistinct as(String alias) {
         return new CountDistinct(column, alias);
     }
 
     public static CountDistinct of(BasicColumn column) {
-        return new CountDistinct(column, null);
+        return new CountDistinct(column);
     }
 }