9.2 List/Map

Using Map to receive query results is the most versatile approach. Each row is represented as a Map<String, Object> mapping column names to values, without needing to predefine entity classes.

Single row query

Map<String, Object> data = jdbc.queryForMap("select * from users where id = 1");

How to Use

Example: Programmatic API

List<Map<String, Object>> result = jdbc.queryForList("select * from users");

Example: Declarative API

@SimpleMapper
public interface UserMapper {
    @Query("select * from users where id > #{id}")
    List<Map<String, Object>> listUsers(@Param("id") long searchId);
}

Example: Builder API

List<Map<String, Object>> result = lambda.query(User.class)
                                         .le(User::getId, 100)
                                         .queryForMapList();

Example: Mapper File

<select id="queryListByAge" resultType="map">
    select * from users where age = #{age}
</select>

resultType options

Value	Corresponding Type	Description
map	LinkedCaseInsensitiveMap (default)	Column name case-insensitive, affected by global configuration
hashmap	HashMap	Unordered, column name case-sensitive
linkedmap	LinkedHashMap	Maintains insertion order, column name case-sensitive
caseinsensitivemap	LinkedCaseInsensitiveMap	Column name case-insensitive

Column Name Case Sensitivity

Different databases may return column names with different casing. Oracle often returns uppercase column names, while MySQL often returns lowercase names. dbVisitor uses a case-insensitive Map by default so both row.get("id") and row.get("ID") can work.

Default: case-insensitive column names

List<Map<String, Object>> rows = jdbc.queryForList("select * from users");
Object id = rows.get(0).get("id");
Object sameId = rows.get(0).get("ID");

If you want to preserve the exact column-name casing returned by the driver, disable this behavior.

Strict case sensitivity

JdbcTemplate jdbc = ...;
jdbc.setResultsCaseInsensitive(false);

List<Map<String, Object>> rows = jdbc.queryForList("select * from users");

After disabling it, results are stored in LinkedHashMap, and column-name keys become case-sensitive.