MyBatis中association和collection中的column傳入多個參數

mybatis中association和collection的column傳入多個參數值

項目中在使用association和collection實現一對一和一對多關係時需要對關係中結果集進行篩選，如果使用懶加載模式，即聯合使用select標籤時，主sql和關係映射裏的sql是分開的，查詢參數傳遞成爲問題。

mybatis文檔:

property	description
column	數據庫的列名或者列標籤別名。與傳遞給resultSet.getString(columnName)的參數名稱相同。注意： 在處理組合鍵時，您可以使用column=“{prop1=col1,prop2=col2}”這樣的語法，設置多個列名傳入到嵌套查詢語句。這就會把prop1和prop2設置到目標嵌套選擇語句的參數對象中。

<resultMap id="findCountryCityAddressMap" type="map">
    <result property="country" column="country"/>
    <collection property="cityList"
                column="{cityId=city_id,adr=addressCol, dis=districtCol}" //adr作爲第二個sql查詢條件key,即prop1屬性
                ofType="map"                                              //addressCol即爲虛擬列名
                javaType="java.util.List" select="selectAddressByCityId"/>
</resultMap>

<resultMap id="selectAddressByCityIdMap" type="map">
    <result property="city" column="city"/>
    <collection property="addressList" column="city" ofType="map" javaType="java.util.List">
        <result property="address" column="address"/>
        <result property="district" column="district"/>
    </collection>
</resultMap>

<select id="findCountryCityAddress" resultMap="findCountryCityAddressMap">
    SELECT
        ct.country,
        ci.city_id,
        IFNULL(#{addressQuery},'') addressCol, //爲傳入查詢條件,構造虛擬列，虛擬列爲查詢條件參數值
        IFNULL(#{districtQuery},'') districtCol
    FROM
        country ct
    LEFT JOIN city ci ON ct.country_id = ci.country_id
    ORDER BY ct.country_id
</select>

<select id="selectAddressByCityId" parameterType="java.util.Map" resultMap="selectAddressByCityIdMap">
    SELECT
        ci.city,
        ads.address,
      ads.district
    FROM
        (
            SELECT
                city,
                city_id
            FROM
                city ci
            WHERE
                ci.city_id = #{cityId}
        ) ci
    LEFT JOIN address ads ON ads.city_id = ci.city_id
    <where>
        <if test="adr!=null and adr!=''">
            and ads.address RegExp #{adr}
        </if>
        <if test="dis!=null and dis!=''">
            ads.district Regexp #{dis}
        </if>
    </where>

</select>

測試文件:

@Test
public void findCountryCityAddressTest() throws JsonProcessingException {
    Map<String,Object> param = new HashMap<>();
    param.put("addressQuery","1168");
    List<Map<String, Object>> rs = countryManager.findCountryCityAddress(param);
    ObjectMapper mapper = new ObjectMapper();
    ObjectWriter writer = mapper.writerWithDefaultPrettyPrinter();
    System.out.println(writer.writeValueAsString(rs));
}

測試結果:

[
    {
        "country": "Afghanistan",
        "cityList": [{
                "city": "Kabul",
                "addressList": [{
                        "address": "1168 Najafabad Parkway",
                        "district": "Kabol"
                    }
                ]
            }
        ],
        "city_id": 251
    },
    {
        "country": "Algeria",
        "cityList": [],
        "city_id": 59
    }
]

可以看到，確實將查詢條件通過column參數傳入到第二個sql中，並執行成功