Use consistent build pattern

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/delete/DeleteDSL.java

@@ -78,15 +78,14 @@ public DeleteDSL<R> orderBy(Collection<? extends SortSpecification> columns) {
     @NotNull
     @Override
     public R build() {
-        DeleteModel.Builder deleteModelBuilder = DeleteModel.withTable(table)
+        DeleteModel deleteModel = DeleteModel.withTable(table)
                 .withTableAlias(tableAlias)
                 .withLimit(limit)
-                .withOrderByModel(orderByModel);
-        if (whereBuilder != null) {
-            deleteModelBuilder.withWhereModel(whereBuilder.buildWhereModel());
-        }
+                .withOrderByModel(orderByModel)
+                .withWhereModel(whereBuilder == null ? null : whereBuilder.buildWhereModel())
+                .build();
 
-        return adapterFunction.apply(deleteModelBuilder.build());
+        return adapterFunction.apply(deleteModel);
     }
 
     @Override

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

@@ -25,6 +25,7 @@
 import org.mybatis.dynamic.sql.SqlTable;
 import org.mybatis.dynamic.sql.configuration.StatementConfiguration;
 import org.mybatis.dynamic.sql.util.Buildable;
+import org.mybatis.dynamic.sql.util.Utilities;
 import org.mybatis.dynamic.sql.where.AbstractWhereFinisher;
 import org.mybatis.dynamic.sql.where.WhereModel;
 
@@ -33,7 +34,7 @@
  * clauses, but not the other parts of a select (group by, order by, etc.) Count queries always return
  * a long. If these restrictions are not acceptable, then use the Select DSL for an unrestricted select statement.
  *
- * @param <R> the type of model built by this Builder. Typically SelectModel.
+ * @param <R> the type of model built by this Builder. Typically, SelectModel.
  *
  * @author Jeff Butler
  */
@@ -53,9 +54,7 @@ private CountDSL(BasicColumn countColumn, SqlTable table, Function<SelectModel,
 
     @Override
     public CountWhereBuilder where() {
-        if (whereBuilder == null) {
-            whereBuilder = new CountWhereBuilder();
-        }
+        whereBuilder = Utilities.buildIfNecessary(whereBuilder, CountWhereBuilder::new);
         return whereBuilder;
     }
 
@@ -72,19 +71,16 @@ public CountDSL<R> configureStatement(Consumer<StatementConfiguration> consumer)
     }
 
     private SelectModel buildModel() {
-        QueryExpressionModel.Builder b = new QueryExpressionModel.Builder()
+        QueryExpressionModel queryExpressionModel = new QueryExpressionModel.Builder()
                 .withSelectColumn(countColumn)
                 .withTable(table())
-                .withTableAliases(tableAliases());
-
-        if (whereBuilder != null) {
-            b.withWhereModel(whereBuilder.buildWhereModel());
-        }
-
-        buildJoinModel().ifPresent(b::withJoinModel);
+                .withTableAliases(tableAliases())
+                .withJoinModel(buildJoinModel().orElse(null))
+                .withWhereModel(whereBuilder == null ? null : whereBuilder.buildWhereModel())
+                .build();
 
         return new SelectModel.Builder()
-                .withQueryExpression(b.build())
+                .withQueryExpression(queryExpressionModel)
                 .build();
     }
 

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

@@ -85,9 +85,7 @@ public QueryExpressionDSL<R> configureStatement(Consumer<StatementConfiguration>
      * @return The having builder
      */
     protected QueryExpressionHavingBuilder having() {
-        if (havingBuilder == null) {
-            havingBuilder = new QueryExpressionHavingBuilder();
-        }
+        havingBuilder = Utilities.buildIfNecessary(havingBuilder, QueryExpressionHavingBuilder::new);
         return havingBuilder;
     }
 
@@ -185,23 +183,16 @@ public UnionBuilder unionAll() {
     }
 
     protected QueryExpressionModel buildModel() {
-        QueryExpressionModel.Builder builder = QueryExpressionModel.withSelectList(selectList)
+        return QueryExpressionModel.withSelectList(selectList)
                 .withConnector(connector)
                 .withTable(table())
                 .isDistinct(isDistinct)
                 .withTableAliases(tableAliases())
                 .withJoinModel(buildJoinModel().orElse(null))
-                .withGroupByModel(groupByModel);
-
-        if (whereBuilder != null) {
-            builder.withWhereModel(whereBuilder.buildWhereModel());
-        }
-
-        if (havingBuilder != null) {
-            builder.withHavingModel(havingBuilder.buildHavingModel());
-        }
-
-        return builder.build();
+                .withGroupByModel(groupByModel)
+                .withWhereModel(whereBuilder == null ? null : whereBuilder.buildWhereModel())
+                .withHavingModel(havingBuilder == null ? null : havingBuilder.buildHavingModel())
+                .build();
     }
 
     public SelectDSL<R>.LimitFinisher limit(long limit) {

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

@@ -98,17 +98,15 @@ public UpdateDSL<R> orderBy(Collection<? extends SortSpecification> columns) {
     @NotNull
     @Override
     public R build() {
-        UpdateModel.Builder updateModelBuilder = UpdateModel.withTable(table)
+        UpdateModel updateModel = UpdateModel.withTable(table)
                 .withTableAlias(tableAlias)
                 .withColumnMappings(columnMappings)
                 .withLimit(limit)
-                .withOrderByModel(orderByModel);
+                .withOrderByModel(orderByModel)
+                .withWhereModel(whereBuilder == null ? null : whereBuilder.buildWhereModel())
+                .build();
 
-        if (whereBuilder != null) {
-            updateModelBuilder.withWhereModel(whereBuilder.buildWhereModel());
-        }
-
-        return adapterFunction.apply(updateModelBuilder.build());
+        return adapterFunction.apply(updateModel);
     }
 
     @Override