1. JDBC
spring.datasource.url=jdbc:postgresql://127.0.0.1:5432/postgres
spring.datasource.username=postgres
spring.datasource.password=deb.deb
spring.datasource.driver-class-name=org.postgresql.Driver
@Service
public class UserService {
@Autowired
private JdbcTemplate jdbcTemplate;
public List<User> getList(){
String sql = "SELECT id, name, password FROM test.user ";
return (List<User>) jdbcTemplate.query(sql, new RowMapper<User>(){
@Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
User user = new User();
user.setId(rs.getInt("id"));
user.setName(rs.getString("name"));
user.setPassword(rs.getString("password"));
return user;
}
});
}
}
2. Mybatis
- 在mapper.xml中insert操作使用useGeneratedKeys="true"和keyProperty="id"时，需要提前在数据库中建表时设好自增键。Mybatis并不能自动建表？
- 接口+xml方式
mybatis.config-locations=classpath:mybatis/mybatis-config.xml
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml
mybatis.type-aliases-package=com.main.model
@SpringBootApplication
@MapperScan("com.main.mapper")
public class SpringBootProgresqlApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootProgresqlApplication.class, args);
}
}
public interface UserMapper {
List<UserEntity> getAll();
UserEntity getOne(Long id);
void insert(UserEntity user);
void update(UserEntity user);
void delete(Long id);
}
<!-- mybatis-config.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<typeAliases>
<typeAlias alias="Integer" type="java.lang.Integer" />
<typeAlias alias="Long" type="java.lang.Long" />
<typeAlias alias="HashMap" type="java.util.HashMap" />
<typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap" />
<typeAlias alias="ArrayList" type="java.util.ArrayList" />
<typeAlias alias="LinkedList" type="java.util.LinkedList" />
</typeAliases>
</configuration>
<!-- UserMapper.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.main.mapper.UserMapper" >
<resultMap id="BaseResultMap" type="com.main.model.UserEntity" >
<id column="id" property="id" jdbcType="BIGINT" />
<result column="userName" property="userName" jdbcType="VARCHAR" />
<result column="passWord" property="passWord" jdbcType="VARCHAR" />
<result column="user_sex" property="userSex" jdbcType="VARCHAR"/>
<result column="nick_name" property="nickName" jdbcType="VARCHAR" />
</resultMap>
<sql id="Base_Column_List" >
id, userName, passWord, user_sex, nick_name
</sql>
<select id="getAll" resultMap="BaseResultMap" >
SELECT
<include refid="Base_Column_List" />
FROM test.userentity
</select>
<select id="getOne" parameterType="java.lang.Long" resultMap="BaseResultMap" >
SELECT
<include refid="Base_Column_List" />
FROM test.userentity
WHERE id = #{id}
</select>
<insert id="insert" parameterType="com.main.model.UserEntity" >
INSERT INTO
test.userentity
(userName,passWord,user_sex)
VALUES
(#{userName}, #{passWord}, #{userSex})
</insert>
<update id="update" parameterType="com.main.model.UserEntity" >
UPDATE
test.userentity
SET
<if test="userName != null">userName = #{userName},</if>
<if test="passWord != null">passWord = #{passWord},</if>
nick_name = #{nickName}
WHERE
id = #{id}
</update>
<delete id="delete" parameterType="java.lang.Long" >
DELETE FROM
test.userentity
WHERE
id =#{id}
</delete>
</mapper>
- 使用mapper和provider
- 简洁但处理复杂业务则代码可读性不好（如果用provider来拼sql其实也还好，比如直接写一长段sql好一点）
- mapper包下面定义访问数据的方法，可以直接用sql语句，也可以指定provider类中的方法拼接sql，也可以使用xml文件
- provider包下面相当于动态拼接sql语句，也类似于传统的mybatis的xml文件的作用
@Mapper
public interface EUserInfoMapper {
/**
*用户登录
* @param userName
* @param pwd
* @return
*/
@Select("select * from `staff` where id=#{userName} and password=#{pwd}")
EUser login(@Param("userName") String userName,@Param("pwd") String pwd);
* @return
*/
@SelectProvider(type = UserSqlProvider.class, method = "getUsersFilter")
List<EUser> serachUsers(SerachUserVO serachUserVO);
}
public class UserSqlProvider {
public String getUsersFilter(final SerachUserVO serachUserVO) {
String sql =new SQL() {
{
SELECT("*");
FROM("staff");
WHERE("del_flag=0");
if (StringUtil.isNotEmpty(serachUserVO.getUser_name())) {
WHERE("id=#{user_name}");
}
if (StringUtil.isNotEmpty(serachUserVO.getReal_name())) {
WHERE("name=#{real_name}");
}
if (StringUtil.isNotEmpty(serachUserVO.getMobile())) {
WHERE("cell_phone=#{mobile}");
}
ORDER_BY("id desc limit #{page_index},#{page_size}");
}
}.toString();
return sql;
}
}
@select("select * from t_user ")
public list<User> findAll();
3. JPA（Hibernate）
- 在model类中使用@Id和@GeneratedValue(strategy = GenerationType.AUTO)，可以在自动建表时定义自增列，不需要再自己操作数据定义表
