Use jdbcType="CURSOR" for indicator; removed NESTED_CURSOR

Author: harawata

src/main/java/org/apache/ibatis/executor/resultset/DefaultResultSetHandler.java

@@ -532,7 +532,7 @@ private boolean applyPropertyMappings(ResultSetWrapper rsw, ResultMap resultMap,
     final List<ResultMapping> propertyMappings = resultMap.getPropertyResultMappings();
     for (ResultMapping propertyMapping : propertyMappings) {
       String column = prependPrefix(propertyMapping.getColumn(), columnPrefix);
-      if (propertyMapping.getNestedResultMapId() != null) {
+      if (propertyMapping.getNestedResultMapId() != null && !JdbcType.CURSOR.equals(propertyMapping.getJdbcType())) {
         // the user added a column attribute to a nested result map, ignore it
         column = null;
       }
@@ -568,28 +568,33 @@ private Object getPropertyMappingValue(ResultSet rs, MetaObject metaResultObject
     if (propertyMapping.getNestedQueryId() != null) {
       return getNestedQueryMappingValue(rs, metaResultObject, propertyMapping, lazyLoader, columnPrefix);
     }
+    if (JdbcType.CURSOR.equals(propertyMapping.getJdbcType())) {
+      return getNestedCursorValue(rs, metaResultObject, propertyMapping, columnPrefix);
+    }
     if (propertyMapping.getResultSet() != null) {
-      if (ResultMapping.NESTED_CURSOR.equals(propertyMapping.getResultSet())) {
-        final String column = prependPrefix(propertyMapping.getColumn(), columnPrefix);
-        ResultMap nestedResultMap = resolveDiscriminatedResultMap(rs,
-            configuration.getResultMap(propertyMapping.getNestedResultMapId()),
-            getColumnPrefix(columnPrefix, propertyMapping));
-        ResultSetWrapper rsw = new ResultSetWrapper(rs.getObject(column, ResultSet.class), configuration);
-        List<Object> results = new ArrayList<>();
-        handleResultSet(rsw, nestedResultMap, results, null);
-        linkObjects(metaResultObject, propertyMapping, results.get(0), true);
-        return metaResultObject.getValue(propertyMapping.getProperty());
-      } else {
-        addPendingChildRelation(rs, metaResultObject, propertyMapping); // TODO is that OK?
-        return DEFERRED;
-      }
+      addPendingChildRelation(rs, metaResultObject, propertyMapping); // TODO is that OK?
+      return DEFERRED;
     } else {
       final TypeHandler<?> typeHandler = propertyMapping.getTypeHandler();
       final String column = prependPrefix(propertyMapping.getColumn(), columnPrefix);
       return typeHandler.getResult(rs, column);
     }
   }
 
+  private Object getNestedCursorValue(ResultSet rs, MetaObject metaResultObject, ResultMapping propertyMapping,
+      String parentColumnPrefix) throws SQLException {
+    final String column = prependPrefix(propertyMapping.getColumn(), parentColumnPrefix);
+    final String property = propertyMapping.getProperty();
+    ResultMap nestedResultMap = resolveDiscriminatedResultMap(rs,
+        configuration.getResultMap(propertyMapping.getNestedResultMapId()),
+        getColumnPrefix(parentColumnPrefix, propertyMapping));
+    ResultSetWrapper rsw = new ResultSetWrapper(rs.getObject(column, ResultSet.class), configuration);
+    List<Object> results = new ArrayList<>();
+    handleResultSet(rsw, nestedResultMap, results, null);
+    linkObjects(metaResultObject, propertyMapping, results.get(0), true);
+    return metaResultObject.getValue(property);
+  }
+
   private List<UnMappedColumnAutoMapping> createAutomaticMappings(ResultSetWrapper rsw, ResultMap resultMap,
       MetaObject metaObject, String columnPrefix) throws SQLException {
     final String mapKey = resultMap.getId() + ":" + columnPrefix;

src/main/java/org/apache/ibatis/mapping/MappedStatement.java

@@ -16,7 +16,6 @@
 package org.apache.ibatis.mapping;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
@@ -204,11 +203,6 @@ public MappedStatement build() {
       assert mappedStatement.id != null;
       assert mappedStatement.sqlSource != null;
       assert mappedStatement.lang != null;
-      if (mappedStatement.resultSets != null
-          && Arrays.asList(mappedStatement.resultSets).contains(ResultMapping.NESTED_CURSOR)) {
-        throw new IllegalStateException(
-            "Result set name '" + ResultMapping.NESTED_CURSOR + "' is reserved, please assign another name.");
-      }
       mappedStatement.resultMaps = Collections.unmodifiableList(mappedStatement.resultMaps);
       return mappedStatement;
     }

src/main/java/org/apache/ibatis/mapping/ResultMap.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2024 the original author or authors.
+ *    Copyright 2009-2025 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.
@@ -30,6 +30,7 @@
 import org.apache.ibatis.logging.LogFactory;
 import org.apache.ibatis.reflection.ParamNameUtil;
 import org.apache.ibatis.session.Configuration;
+import org.apache.ibatis.type.JdbcType;
 
 /**
  * @author Clinton Begin
@@ -93,8 +94,8 @@ public ResultMap build() {
       final List<String> constructorArgNames = new ArrayList<>();
       for (ResultMapping resultMapping : resultMap.resultMappings) {
         resultMap.hasNestedQueries = resultMap.hasNestedQueries || resultMapping.getNestedQueryId() != null;
-        resultMap.hasNestedResultMaps = resultMap.hasNestedResultMaps
-            || resultMapping.getNestedResultMapId() != null && resultMapping.getResultSet() == null;
+        resultMap.hasNestedResultMaps = resultMap.hasNestedResultMaps || resultMapping.getNestedResultMapId() != null
+            && resultMapping.getResultSet() == null && !JdbcType.CURSOR.equals(resultMapping.getJdbcType());
         final String column = resultMapping.getColumn();
         if (column != null) {
           resultMap.mappedColumns.add(column.toUpperCase(Locale.ENGLISH));

src/main/java/org/apache/ibatis/mapping/ResultMapping.java

@@ -30,11 +30,6 @@
  */
 public class ResultMapping {
 
-  /**
-   * Reserved result set name indicating a nested cursor is mapped to this property.
-   */
-  public static final String NESTED_CURSOR = "NESTED_CURSOR";
-
   private Configuration configuration;
   private String property;
   private String column;
@@ -171,8 +166,7 @@ private void validate() {
         if (resultMapping.foreignColumn != null) {
           numForeignColumns = resultMapping.foreignColumn.split(",").length;
         }
-        if (numColumns != numForeignColumns && !NESTED_CURSOR.equals(resultMapping.resultSet)) {
-          // Nested cursor does not use 'foreignKey'
+        if (numColumns != numForeignColumns) {
           throw new IllegalStateException(
               "There should be the same number of columns and foreignColumns in property " + resultMapping.property);
         }

src/site/es/xdoc/sqlmap-xml.xml

@@ -1437,7 +1437,7 @@ Here is the statement and result map.</p>
 <source><![CDATA[<resultMap id="blogResult" type="Blog">
   <id property="id" column="id" />
   <result property="title" column="title" />
-  <association property="author" column="author" resultSet="NESTED_CURSOR">
+  <association property="author" column="author" jdbcType="CURSOR">
     <id property="id" column="id" />
     <result property="username" column="username" />
   </association>
@@ -1449,8 +1449,8 @@ Here is the statement and result map.</p>
   ) author from blog b
 </select>]]></source>
 
-<p>Compared to the examples in the previous section, the key difference is the <code>resultSet</code> attribute in the <code>&lt;association&gt;</code> element.<br />
-Its value <code>NESTED_CURSOR</code> indicates that the value of the column <code>author</code> is nested cursor.</p>
+<p>Compared to the examples in the previous section, the key difference is the <code>jdbcType</code> attribute in the <code>&lt;association&gt;</code> element.<br />
+Its value <code>CURSOR</code> indicates that the value of the column <code>author</code> is nested cursor.</p>
 
 
         <h4>ResultSets múltiples en Association</h4>
@@ -1630,12 +1630,12 @@ SELECT * FROM AUTHOR WHERE ID = #{id}]]></source>
 <h4>Nested Cursor for Collection</h4>
 
 <p>It might be obvious, but nested cursor can return multiple rows.<br />
-Just like <code>&lt;association&gt;</code>, you just need to specify <code>resultSet="NESTED_CURSOR"</code> in the <code>&lt;collection&gt;</code> element.</p>
+Just like <code>&lt;association&gt;</code>, you just need to specify <code>jdbcType="CURSOR"</code> in the <code>&lt;collection&gt;</code> element.</p>
 
 <source><![CDATA[<resultMap id="blogResult" type="Blog">
   <id property="id" column="id" />
   <result property="title" column="title" />
-  <collection property="posts" column="posts" resultSet="NESTED_CURSOR">
+  <collection property="posts" column="posts" jdbcType="CURSOR">
     <id property="id" column="id" />
     <result property="subject" column="subject" />
     <result property="body" column="body" />

src/site/ja/xdoc/sqlmap-xml.xml

@@ -1617,7 +1617,7 @@ User{username=Peter, roles=[Users, Maintainers, Approvers]}
 <source><![CDATA[<resultMap id="blogResult" type="Blog">
   <id property="id" column="id" />
   <result property="title" column="title" />
-  <association property="author" column="author" resultSet="NESTED_CURSOR">
+  <association property="author" column="author" jdbcType="CURSOR">
     <id property="id" column="id" />
     <result property="username" column="username" />
   </association>
@@ -1629,7 +1629,7 @@ User{username=Peter, roles=[Users, Maintainers, Approvers]}
   ) author from blog b
 </select>]]></source>
 
-<p>上の章の例との重要な違いは、<code>&lt;association&gt;</code> 要素の <code>resultSet</code> 属性に特別な値 <code>NESTED_CURSOR</code> を指定している点です。<br />
+<p>上の章の例との重要な違いは、<code>&lt;association&gt;</code> 要素の <code>jdbcType</code> 属性に <code>CURSOR</code> を指定している点です。<br />
 これによって、<code>author</code> 列の値をネストされたカーソルとしてマッピングすることができます。</p>
 
 
@@ -1818,12 +1818,12 @@ SELECT * FROM AUTHOR WHERE ID = #{id}]]></source>
 <h4>ネストされたカーソルを collection にマッピングする</h4>
 
 <p>当然ですが、ネストされたカーソルが複数の値を返す場合もあります。<br />
-先に説明した <code>&lt;association&gt;</code> の場合と同様、 <code>&lt;collection&gt;</code> 要素に <code>resultSet="NESTED_CURSOR"</code> を指定してください。</p>
+先に説明した <code>&lt;association&gt;</code> の場合と同様、 <code>&lt;collection&gt;</code> 要素に <code>jdbcType="CURSOR"</code> を指定してください。</p>
 
 <source><![CDATA[<resultMap id="blogResult" type="Blog">
   <id property="id" column="id" />
   <result property="title" column="title" />
-  <collection property="posts" column="posts" resultSet="NESTED_CURSOR">
+  <collection property="posts" column="posts" jdbcType="CURSOR">
     <id property="id" column="id" />
     <result property="subject" column="subject" />
     <result property="body" column="body" />

src/site/ko/xdoc/sqlmap-xml.xml

@@ -1464,7 +1464,7 @@ Here is the statement and result map.</p>
 <source><![CDATA[<resultMap id="blogResult" type="Blog">
   <id property="id" column="id" />
   <result property="title" column="title" />
-  <association property="author" column="author" resultSet="NESTED_CURSOR">
+  <association property="author" column="author" jdbcType="CURSOR">
     <id property="id" column="id" />
     <result property="username" column="username" />
   </association>
@@ -1476,8 +1476,8 @@ Here is the statement and result map.</p>
   ) author from blog b
 </select>]]></source>
 
-<p>Compared to the examples in the previous section, the key difference is the <code>resultSet</code> attribute in the <code>&lt;association&gt;</code> element.<br />
-Its value <code>NESTED_CURSOR</code> indicates that the value of the column <code>author</code> is nested cursor.</p>
+<p>Compared to the examples in the previous section, the key difference is the <code>jdbcType</code> attribute in the <code>&lt;association&gt;</code> element.<br />
+Its value <code>CURSOR</code> indicates that the value of the column <code>author</code> is nested cursor.</p>
 
 
         <h4>Multiple ResultSets for Association</h4>
@@ -1662,12 +1662,12 @@ SELECT * FROM AUTHOR WHERE ID = #{id}]]></source>
 <h4>Nested Cursor for Collection</h4>
 
 <p>It might be obvious, but nested cursor can return multiple rows.<br />
-Just like <code>&lt;association&gt;</code>, you just need to specify <code>resultSet="NESTED_CURSOR"</code> in the <code>&lt;collection&gt;</code> element.</p>
+Just like <code>&lt;association&gt;</code>, you just need to specify <code>jdbcType="CURSOR"</code> in the <code>&lt;collection&gt;</code> element.</p>
 
 <source><![CDATA[<resultMap id="blogResult" type="Blog">
   <id property="id" column="id" />
   <result property="title" column="title" />
-  <collection property="posts" column="posts" resultSet="NESTED_CURSOR">
+  <collection property="posts" column="posts" jdbcType="CURSOR">
     <id property="id" column="id" />
     <result property="subject" column="subject" />
     <result property="body" column="body" />

src/site/markdown/sqlmap-xml.md

@@ -948,7 +948,7 @@ Here is the statement and result map.
 <resultMap id="blogResult" type="Blog">
   <id property="id" column="id" />
   <result property="title" column="title" />
-  <association property="author" column="author" resultSet="NESTED_CURSOR">
+  <association property="author" column="author" jdbcType="CURSOR">
     <id property="id" column="id" />
     <result property="username" column="username" />
   </association>
@@ -961,8 +961,9 @@ Here is the statement and result map.
 </select>
 ```
 
-Compared to the examples in the previous section, the key difference is the `resultSet` attribute in the `<association>` element.
-Its value `NESTED_CURSOR` indicates that the value of the column `author` is nested cursor.
+Compared to the examples in the previous section, the key difference is the `jdbcType` attribute in the `<association>` element.
+Its value `CURSOR` indicates that the value of the column `author` is nested cursor.
+
 
 #### Multiple ResultSets for Association
 
@@ -1009,6 +1010,7 @@ Now we can specify that the data to fill the "author" association comes in the "
 </resultMap>
 ```
 
+
 You've seen above how to deal with a "has one" type association. But what about "has many"? That's the subject of the next section.
 
 #### collection
@@ -1119,13 +1121,13 @@ Also, if you prefer the longer form that allows for more reusability of your res
 #### Nested Cursor for Collection
 
 It might be obvious, but nested cursor can return multiple rows.
-Just like `<association>`, you just need to specify `resultSet="NESTED_CURSOR"` in the `<collection>` element.
+Just like `<association>`, you just need to specify `jdbcType="CURSOR""` in the `<collection>` element.
 
 ```xml
 <resultMap id="blogResult" type="Blog">
   <id property="id" column="id" />
   <result property="title" column="title" />
-  <collection property="posts" column="posts" resultSet="NESTED_CURSOR">
+  <collection property="posts" column="posts" jdbcType="CURSOR">
     <id property="id" column="id" />
     <result property="subject" column="subject" />
     <result property="body" column="body" />

src/site/zh_CN/xdoc/sqlmap-xml.xml

@@ -1669,7 +1669,7 @@ Here is the statement and result map.</p>
 <source><![CDATA[<resultMap id="blogResult" type="Blog">
   <id property="id" column="id" />
   <result property="title" column="title" />
-  <association property="author" column="author" resultSet="NESTED_CURSOR">
+  <association property="author" column="author" jdbcType="CURSOR">
     <id property="id" column="id" />
     <result property="username" column="username" />
   </association>
@@ -1681,8 +1681,8 @@ Here is the statement and result map.</p>
   ) author from blog b
 </select>]]></source>
 
-<p>Compared to the examples in the previous section, the key difference is the <code>resultSet</code> attribute in the <code>&lt;association&gt;</code> element.<br />
-Its value <code>NESTED_CURSOR</code> indicates that the value of the column <code>author</code> is nested cursor.</p>
+<p>Compared to the examples in the previous section, the key difference is the <code>jdbcType</code> attribute in the <code>&lt;association&gt;</code> element.<br />
+Its value <code>CURSOR</code> indicates that the value of the column <code>author</code> is nested cursor.</p>
 
 
         <h4>关联的多结果集（ResultSet）</h4>
@@ -1879,12 +1879,12 @@ SELECT * FROM AUTHOR WHERE ID = #{id}]]></source>
 <h4>Nested Cursor for Collection</h4>
 
 <p>It might be obvious, but nested cursor can return multiple rows.<br />
-Just like <code>&lt;association&gt;</code>, you just need to specify <code>resultSet="NESTED_CURSOR"</code> in the <code>&lt;collection&gt;</code> element.</p>
+Just like <code>&lt;association&gt;</code>, you just need to specify <code>jdbcType="CURSOR"</code> in the <code>&lt;collection&gt;</code> element.</p>
 
 <source><![CDATA[<resultMap id="blogResult" type="Blog">
   <id property="id" column="id" />
   <result property="title" column="title" />
-  <collection property="posts" column="posts" resultSet="NESTED_CURSOR">
+  <collection property="posts" column="posts" jdbcType="CURSOR">
     <id property="id" column="id" />
     <result property="subject" column="subject" />
     <result property="body" column="body" />