<select id="selectByParams" resultType="order">
select
<include refid="Base_Column_List" />
from order
where id = #{id,jdbcType=BIGINT}
</select>
上下两块代码块区别在于resultType和resultMap。
<select id="selectByParams" resultMap="BaseResultMap">
select
<include refid="Base_Column_List" />
from order
where id = #{id,jdbcType=BIGINT}
</select>
</select>
当sql查出数据sql参数字段和实体字段不匹配时就会错误,无法将结果集匹配set
具体源码:
private List<UnMappedColumnAutoMapping> createAutomaticMappings(ResultSetWrapper rsw, ResultMap resultMap, MetaObject metaObject, String columnPrefix) throws SQLException {
final String mapKey = resultMap.getId() + ":" + columnPrefix;
List<UnMappedColumnAutoMapping> autoMapping = autoMappingsCache.get(mapKey);
if (autoMapping == null) {
autoMapping = new ArrayList<UnMappedColumnAutoMapping>();
final List<String> unmappedColumnNames = rsw.getUnmappedColumnNames(resultMap, columnPrefix);
for (String columnName : unmappedColumnNames) {
String propertyName = columnName;
if (columnPrefix != null && !columnPrefix.isEmpty()) {
// When columnPrefix is specified,
// ignore columns without the prefix.
if (columnName.toUpperCase(Locale.ENGLISH).startsWith(columnPrefix)) {
propertyName = columnName.substring(columnPrefix.length());
} else {
continue;
}
}
final String property = metaObject.findProperty(propertyName, configuration.isMapUnderscoreToCamelCase());
//匹配是否有结果map 或者实体是否能获取到set方法
if (property != null && metaObject.hasSetter(property)) {
if (resultMap.getMappedProperties().contains(property)) {
continue;
}
final Class<?> propertyType = metaObject.getSetterType(property);
if (typeHandlerRegistry.hasTypeHandler(propertyType, rsw.getJdbcType(columnName))) {
final TypeHandler<?> typeHandler = rsw.getTypeHandler(propertyType, columnName);
autoMapping.add(new UnMappedColumnAutoMapping(columnName, property, typeHandler, propertyType.isPrimitive()));
} else {
configuration.getAutoMappingUnknownColumnBehavior()
.doAction(mappedStatement, columnName, property, propertyType);
}
} else {
configuration.getAutoMappingUnknownColumnBehavior()
.doAction(mappedStatement, columnName, (property != null) ? property : propertyName, null);
}
}
autoMappingsCache.put(mapKey, autoMapping);
}
return autoMapping;
}
网友评论