Move query expression rendering fully into Query Expression Renderer

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/select/render/QueryExpression.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2017 the original author or authors.
+ *    Copyright 2016-2019 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.
@@ -22,6 +22,8 @@
 import java.util.stream.Collector;
 import java.util.stream.Collectors;
 
+import org.mybatis.dynamic.sql.util.FragmentAndParameters;
+
 public class QueryExpressionCollector {
     private List<String> queryExpressions = new ArrayList<>();
     private Map<String, Object> parameters = new HashMap<>();
@@ -30,9 +32,9 @@ private QueryExpressionCollector() {
         super();
     }
 
-    private void add(QueryExpression queryExpression) {
-        queryExpressions.add(queryExpression.queryExpression());
-        parameters.putAll(queryExpression.parameters());
+    private void add(FragmentAndParameters fragmentAndParameters) {
+        queryExpressions.add(fragmentAndParameters.fragment());
+        parameters.putAll(fragmentAndParameters.parameters());
     }
 
     private QueryExpressionCollector merge(QueryExpressionCollector other) {
@@ -49,7 +51,7 @@ public Map<String, Object> parameters() {
         return parameters;
     }
 
-    public static Collector<QueryExpression, QueryExpressionCollector, QueryExpressionCollector> collect() {
+    public static Collector<FragmentAndParameters, QueryExpressionCollector, QueryExpressionCollector> collect() {
         return Collector.of(QueryExpressionCollector::new,
                 QueryExpressionCollector::add,
                 QueryExpressionCollector::merge);

src/main/java/org/mybatis/dynamic/sql/select/render/QueryExpressionCollector.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2018 the original author or authors.
+ *    Copyright 2016-2019 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.
@@ -15,6 +15,11 @@
  */
 package org.mybatis.dynamic.sql.select.render;
 
+import static org.mybatis.dynamic.sql.util.StringUtilities.spaceAfter;
+import static org.mybatis.dynamic.sql.util.StringUtilities.spaceBefore;
+
+import java.util.Collections;
+import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -27,6 +32,7 @@
 import org.mybatis.dynamic.sql.select.QueryExpressionModel;
 import org.mybatis.dynamic.sql.select.join.JoinModel;
 import org.mybatis.dynamic.sql.util.CustomCollectors;
+import org.mybatis.dynamic.sql.util.FragmentAndParameters;
 import org.mybatis.dynamic.sql.where.WhereModel;
 import org.mybatis.dynamic.sql.where.render.WhereClauseProvider;
 import org.mybatis.dynamic.sql.where.render.WhereRenderer;
@@ -42,16 +48,31 @@ private QueryExpressionRenderer(Builder builder) {
         sequence = Objects.requireNonNull(builder.sequence);
     }
 
-    public QueryExpression render() {
-        return QueryExpression.withColumnList(calculateColumnList())
-                .withConnector(queryExpression.connector())
-                .isDistinct(queryExpression.isDistinct())
-                .withTableName(calculateTableName(queryExpression.table()))
-                .withJoinClause(queryExpression.joinModel().map(this::renderJoin))
-                .withWhereClause(queryExpression.whereModel().flatMap(this::renderWhereClause))
-                .withGroupByClause(queryExpression.groupByModel().map(this::renderGroupBy))
+    public FragmentAndParameters render() {
+        Optional<WhereClauseProvider> whereClause = queryExpression.whereModel().flatMap(this::renderWhereClause);
+        
+        return FragmentAndParameters.withFragment(calculateQueryExpression(whereClause))
+                .withParameters(calculateParameters(whereClause))
                 .build();
     }
+    
+    private String calculateQueryExpression(Optional<WhereClauseProvider> whereClause) {
+        return spaceAfter(queryExpression.connector())
+                + "select " //$NON-NLS-1$
+                + (queryExpression.isDistinct() ? "distinct " : "") //$NON-NLS-1$ //$NON-NLS-2$
+                + calculateColumnList()
+                + " from " //$NON-NLS-1$
+                + calculateTableName(queryExpression.table())
+                + spaceBefore(queryExpression.joinModel().map(this::renderJoin))
+                + spaceBefore(whereClause.map(WhereClauseProvider::getWhereClause))
+                + spaceBefore(queryExpression.groupByModel().map(this::renderGroupBy));
+    }
+
+    private Map<String, Object> calculateParameters(Optional<WhereClauseProvider> whereClause) {
+        return whereClause
+                .map(WhereClauseProvider::getParameters)
+                .orElse(Collections.emptyMap());
+    }
 
     private String calculateColumnList() {
         return queryExpression.mapColumns(this::applyTableAndColumnAlias)

src/main/java/org/mybatis/dynamic/sql/select/render/QueryExpressionRenderer.java

@@ -28,6 +28,7 @@
 import org.mybatis.dynamic.sql.select.QueryExpressionModel;
 import org.mybatis.dynamic.sql.select.SelectModel;
 import org.mybatis.dynamic.sql.util.CustomCollectors;
+import org.mybatis.dynamic.sql.util.FragmentAndParameters;
 
 public class SelectRenderer {
     private static final String LIMIT_PARAMETER = "_limit"; //$NON-NLS-1$
@@ -59,7 +60,7 @@ public SelectStatementProvider render() {
                 .build();
     }
 
-    private QueryExpression renderQueryExpression(QueryExpressionModel queryExpressionModel) {
+    private FragmentAndParameters renderQueryExpression(QueryExpressionModel queryExpressionModel) {
         return QueryExpressionRenderer.withQueryExpression(queryExpressionModel)
                 .withRenderingStrategy(renderingStrategy)
                 .withSequence(sequence)

src/main/java/org/mybatis/dynamic/sql/select/render/SelectRenderer.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2018 the original author or authors.
+ *    Copyright 2016-2019 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.
@@ -21,44 +21,31 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 
 import org.junit.jupiter.api.Test;
-import org.mybatis.dynamic.sql.where.render.WhereClauseProvider;
+import org.mybatis.dynamic.sql.util.FragmentAndParameters;
 
 public class QueryExpressionCollectorTest {
 
     @Test
     public void testQueryExpressionCollectorMerge() {
-        List<QueryExpression> queryExpressions = new ArrayList<>();
+        List<FragmentAndParameters> queryExpressions = new ArrayList<>();
 
         Map<String, Object> parms1 = new HashMap<>();
         parms1.put("p1", 1);
 
-        WhereClauseProvider wcp1 = WhereClauseProvider.withWhereClause("where fred = ?")
+        FragmentAndParameters fp1 = FragmentAndParameters.withFragment("select foo from bar where fred = ?")
                 .withParameters(parms1)
                 .build();
-        
-        QueryExpression qe1 = QueryExpression.withColumnList("foo")
-                .withConnector(Optional.empty())
-                .withTableName("bar")
-                .withWhereClause(Optional.of(wcp1))
-                .build();
-        queryExpressions.add(qe1);
+        queryExpressions.add(fp1);
 
         Map<String, Object> parms2 = new HashMap<>();
         parms2.put("p2", 2);
 
-        WhereClauseProvider wcp2 = WhereClauseProvider.withWhereClause("where betty = ?")
+        FragmentAndParameters fp2 = FragmentAndParameters.withFragment("union select bar from foo where betty = ?")
                 .withParameters(parms2)
                 .build();
-        
-        QueryExpression qe2 = QueryExpression.withColumnList("bar")
-                .withConnector(Optional.of("union"))
-                .withTableName("foo")
-                .withWhereClause(Optional.of(wcp2))
-                .build();
-        queryExpressions.add(qe2);
+        queryExpressions.add(fp2);
 
         // parallelStream should trigger the merge
         QueryExpressionCollector collector = queryExpressions.parallelStream()