Move creation of the table alias calculator to the rendering phase

jeffgbutler · jeffgbutler · commit bf5c72b4fa7a · 2022-03-01T13:54:07.000-05:00
diff --git a/src/main/java/org/mybatis/dynamic/sql/select/QueryExpressionModel.java b/src/main/java/org/mybatis/dynamic/sql/select/QueryExpressionModel.java
@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2022 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.
@@ -27,8 +27,6 @@
 import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.SqlTable;
 import org.mybatis.dynamic.sql.TableExpression;
-import org.mybatis.dynamic.sql.render.GuaranteedTableAliasCalculator;
-import org.mybatis.dynamic.sql.render.TableAliasCalculator;
 import org.mybatis.dynamic.sql.select.join.JoinModel;
 import org.mybatis.dynamic.sql.where.WhereModel;
 
@@ -38,7 +36,7 @@ public class QueryExpressionModel {
     private final List<BasicColumn> selectList;
     private final TableExpression table;
     private final JoinModel joinModel;
-    private final TableAliasCalculator tableAliasCalculator;
+    private final Map<SqlTable, String> tableAliases;
     private final WhereModel whereModel;
     private final GroupByModel groupByModel;
 
@@ -48,22 +46,11 @@ private QueryExpressionModel(Builder builder) {
         selectList = Objects.requireNonNull(builder.selectList);
         table = Objects.requireNonNull(builder.table);
         joinModel = builder.joinModel;
-        tableAliasCalculator = joinModel().map(jm -> determineJoinTableAliasCalculator(jm, builder.tableAliases))
-                .orElseGet(() -> TableAliasCalculator.of(builder.tableAliases));
+        tableAliases = builder.tableAliases;
         whereModel = builder.whereModel;
         groupByModel = builder.groupByModel;
     }
 
-    private TableAliasCalculator determineJoinTableAliasCalculator(JoinModel joinModel, Map<SqlTable,
-            String> tableAliases) {
-        if (joinModel.containsSubQueries()) {
-            // if there are subQueries, then force explicit qualifiers
-            return TableAliasCalculator.of(tableAliases);
-        } else {
-            return GuaranteedTableAliasCalculator.of(tableAliases);
-        }
-    }
-
     public Optional<String> connector() {
         return Optional.ofNullable(connector);
     }
@@ -80,8 +67,8 @@ public TableExpression table() {
         return table;
     }
 
-    public TableAliasCalculator tableAliasCalculator() {
-        return tableAliasCalculator;
+    public Map<SqlTable, String> tableAliases() {
+        return tableAliases;
     }
 
     public Optional<WhereModel> whereModel() {
diff --git a/src/main/java/org/mybatis/dynamic/sql/select/render/JoinRenderer.java b/src/main/java/org/mybatis/dynamic/sql/select/render/JoinRenderer.java
@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2022 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.
@@ -22,7 +22,7 @@
 import java.util.stream.Collectors;
 
 import org.mybatis.dynamic.sql.BasicColumn;
-import org.mybatis.dynamic.sql.select.QueryExpressionModel;
+import org.mybatis.dynamic.sql.render.TableAliasCalculator;
 import org.mybatis.dynamic.sql.select.join.JoinCriterion;
 import org.mybatis.dynamic.sql.select.join.JoinModel;
 import org.mybatis.dynamic.sql.select.join.JoinSpecification;
@@ -31,13 +31,13 @@
 
 public class JoinRenderer {
     private final JoinModel joinModel;
-    private final QueryExpressionModel queryExpression;
     private final TableExpressionRenderer tableExpressionRenderer;
+    private final TableAliasCalculator tableAliasCalculator;
 
     private JoinRenderer(Builder builder) {
         joinModel = Objects.requireNonNull(builder.joinModel);
-        queryExpression = Objects.requireNonNull(builder.queryExpression);
         tableExpressionRenderer = Objects.requireNonNull(builder.tableExpressionRenderer);
+        tableAliasCalculator = Objects.requireNonNull(builder.tableAliasCalculator);
     }
 
     public FragmentAndParameters render() {
@@ -75,7 +75,7 @@ private String renderCriterion(JoinCriterion joinCriterion) {
     }
 
     private String applyTableAlias(BasicColumn column) {
-        return column.renderWithTableAlias(queryExpression.tableAliasCalculator());
+        return column.renderWithTableAlias(tableAliasCalculator);
     }
 
     public static Builder withJoinModel(JoinModel joinModel) {
@@ -84,21 +84,21 @@ public static Builder withJoinModel(JoinModel joinModel) {
 
     public static class Builder {
         private JoinModel joinModel;
-        private QueryExpressionModel queryExpression;
         private TableExpressionRenderer tableExpressionRenderer;
+        private TableAliasCalculator tableAliasCalculator;
 
         public Builder withJoinModel(JoinModel joinModel) {
             this.joinModel = joinModel;
             return this;
         }
 
-        public Builder withQueryExpression(QueryExpressionModel queryExpression) {
-            this.queryExpression = queryExpression;
+        public Builder withTableExpressionRenderer(TableExpressionRenderer tableExpressionRenderer) {
+            this.tableExpressionRenderer = tableExpressionRenderer;
             return this;
         }
 
-        public Builder withTableExpressionRenderer(TableExpressionRenderer tableExpressionRenderer) {
-            this.tableExpressionRenderer = tableExpressionRenderer;
+        public Builder withTableAliasCalculator(TableAliasCalculator tableAliasCalculator) {
+            this.tableAliasCalculator = tableAliasCalculator;
             return this;
         }
 
diff --git a/src/main/java/org/mybatis/dynamic/sql/select/render/QueryExpressionRenderer.java b/src/main/java/org/mybatis/dynamic/sql/select/render/QueryExpressionRenderer.java
@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2022 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.
@@ -25,7 +25,9 @@
 
 import org.mybatis.dynamic.sql.BasicColumn;
 import org.mybatis.dynamic.sql.TableExpression;
+import org.mybatis.dynamic.sql.render.GuaranteedTableAliasCalculator;
 import org.mybatis.dynamic.sql.render.RenderingStrategy;
+import org.mybatis.dynamic.sql.render.TableAliasCalculator;
 import org.mybatis.dynamic.sql.select.GroupByModel;
 import org.mybatis.dynamic.sql.select.QueryExpressionModel;
 import org.mybatis.dynamic.sql.select.join.JoinModel;
@@ -40,18 +42,33 @@ public class QueryExpressionRenderer {
     private final RenderingStrategy renderingStrategy;
     private final AtomicInteger sequence;
     private final TableExpressionRenderer tableExpressionRenderer;
+    private final TableAliasCalculator tableAliasCalculator;
 
     private QueryExpressionRenderer(Builder builder) {
         queryExpression = Objects.requireNonNull(builder.queryExpression);
         renderingStrategy = Objects.requireNonNull(builder.renderingStrategy);
         sequence = Objects.requireNonNull(builder.sequence);
+        tableAliasCalculator = determineJoinTableAliasCalculator(queryExpression);
         tableExpressionRenderer = new TableExpressionRenderer.Builder()
-                .withTableAliasCalculator(queryExpression.tableAliasCalculator())
+                .withTableAliasCalculator(tableAliasCalculator)
                 .withRenderingStrategy(renderingStrategy)
                 .withSequence(sequence)
                 .build();
     }
 
+    private TableAliasCalculator determineJoinTableAliasCalculator(QueryExpressionModel queryExpression) {
+        return queryExpression.joinModel().map(JoinModel::containsSubQueries).map(containsSubQueries -> {
+            if (containsSubQueries) {
+                // if there are subQueries, then force explicit qualifiers
+                return TableAliasCalculator.of(queryExpression.tableAliases());
+            } else {
+                // there are joins, but no sub-queries. In this case, we can use the
+                // table names as qualifiers without requiring explicit qualifiers
+                return GuaranteedTableAliasCalculator.of(queryExpression.tableAliases());
+            }
+        }).orElseGet(() -> TableAliasCalculator.of(queryExpression.tableAliases()));
+    }
+
     public FragmentAndParameters render() {
         FragmentAndParameters answer = calculateQueryExpressionStart();
         answer = addJoinClause(answer);
@@ -81,7 +98,7 @@ private String calculateColumnList() {
     }
 
     private String applyTableAndColumnAlias(BasicColumn selectListItem) {
-        return selectListItem.renderWithTableAndColumnAlias(queryExpression.tableAliasCalculator());
+        return selectListItem.renderWithTableAndColumnAlias(tableAliasCalculator);
     }
 
     private FragmentAndParameters renderTableExpression(TableExpression table) {
@@ -97,8 +114,8 @@ private FragmentAndParameters addJoinClause(FragmentAndParameters partial) {
 
     private FragmentAndParameters renderJoin(JoinModel joinModel) {
         return JoinRenderer.withJoinModel(joinModel)
-                .withQueryExpression(queryExpression)
                 .withTableExpressionRenderer(tableExpressionRenderer)
+                .withTableAliasCalculator(tableAliasCalculator)
                 .build()
                 .render();
     }
@@ -113,7 +130,7 @@ private FragmentAndParameters addWhereClause(FragmentAndParameters partial) {
     private Optional<WhereClauseProvider> renderWhereClause(WhereModel whereModel) {
         return WhereRenderer.withWhereModel(whereModel)
                 .withRenderingStrategy(renderingStrategy)
-                .withTableAliasCalculator(queryExpression.tableAliasCalculator())
+                .withTableAliasCalculator(tableAliasCalculator)
                 .withSequence(sequence)
                 .build()
                 .render();
@@ -132,7 +149,7 @@ private String renderGroupBy(GroupByModel groupByModel) {
     }
 
     private String applyTableAlias(BasicColumn column) {
-        return column.renderWithTableAlias(queryExpression.tableAliasCalculator());
+        return column.renderWithTableAlias(tableAliasCalculator);
     }
 
     public static Builder withQueryExpression(QueryExpressionModel model) {
