1. pom中引入MyBatis

到Maven倉(cāng)庫(kù), 搜索spring boot mybatis, 復(fù)制最新的maven到pom.xml文件中

<!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.2</version>
</dependency>

2. 創(chuàng)建Mapper

引入了statrer之后，我們不需要做其他額外的配置和依賴(lài)抬探，直接創(chuàng)建Mapper, 這里創(chuàng)建一個(gè)ShopAccountMapper

@Mapper
@Component
public interface ShopAccountMapper {
}

這里使用注解@Mapper來(lái)表示這是一個(gè)Mybatis的Mapper類(lèi)弧可，也可以直接在啟動(dòng)文件中指定mapper類(lèi)所在的包，這樣就可以避免在每個(gè)Mapper類(lèi)上加入@Mapper注解

@MapperScan(basePackages = "shop.leshare.mapper")

簡(jiǎn)單查詢(xún)

在Sql中引用參數(shù)需要用#{}來(lái)表示, 我們?cè)趨?shù)中用@Param來(lái)指定參數(shù)名稱(chēng)候引，否則Mybatis默認(rèn)會(huì)以arg0, arg1, param0, param1這樣的名字來(lái)命名

對(duì)于返回結(jié)果的處理耀销，如果存在實(shí)體屬性和數(shù)據(jù)庫(kù)字段不一致時(shí)淹接，需要用@Result注解指定, 其中property是表示java實(shí)體屬性, column表示數(shù)據(jù)庫(kù)字段

    @Select("select * from shop_account where shop_id=#{shopId} and sub_shop_id=#{subShopId}")
    @Results({
            @Result(property = "shopId", column = "shop_id"),
            @Result(property = "shopName", column = "shop_name"),
            @Result(property = "subShopId", column = "sub_shop_id"),
            @Result(property = "subShopName", column = "sub_shop_name"),
            @Result(property = "createTime", column = "create_time"),
            @Result(property = "updateTime", column = "update_time"),
            @Result(property = "recvAccountType", column = "recv_account_type"),
            @Result(property = "recvValue", column = "recv_value"),
            @Result(property = "recvValue2", column = "recv_value2"),
            @Result(property = "checkName", column = "check_name")
    })
    List<ShopAccount> findAccounts(@Param("shopId") int shopId, @Param("subShopId") int subShopId);

條件查詢(xún)

有時(shí)候我們需要根據(jù)不同的參數(shù)條件進(jìn)行sql拼接，比如這里限佩，僅當(dāng)subShopId大于0的時(shí)候葵诈，才納入查詢(xún)條件，這時(shí)候就要用到@SelectProvider注解犀暑，type指定一個(gè)類(lèi)驯击，method指定該類(lèi)的方法.

Provider中方法返回的是一個(gè)String， 也就是說(shuō)耐亏，在方法里根據(jù)給定的參數(shù)進(jìn)行判斷徊都，返回sql語(yǔ)句即可。當(dāng)Mapper中參數(shù)大于等于2個(gè)時(shí), Provider中方法接收的參數(shù)為Map<String, Object>, Key就是在@Param中指定的名稱(chēng)

注意广辰，當(dāng)Provider參數(shù)包含對(duì)象時(shí)暇矫，要取對(duì)象中的某一個(gè)屬性，可以直接用A.B的方式择吊，比如取User中的name, 直接#{user.name}, 如果是多參數(shù), 這個(gè)user要先從map中取出

    @SelectProvider(type = ShopAccountProvider.class, method = "findList")
    @Results({
            @Result(property = "shopId", column = "shop_id"),
            @Result(property = "shopName", column = "shop_name"),
            @Result(property = "subShopId", column = "sub_shop_id"),
            @Result(property = "subShopName", column = "sub_shop_name"),
            @Result(property = "createTime", column = "create_time"),
            @Result(property = "updateTime", column = "update_time"),
            @Result(property = "recvAccountType", column = "recv_account_type"),
            @Result(property = "recvValue", column = "recv_value"),
            @Result(property = "recvValue2", column = "recv_value2"),
            @Result(property = "checkName", column = "check_name")
    })
    List<ShopAccount> findAccounts(@Param("shopId") int shopId, @Param("subShopId") int subShopId);

public class ShopAccountProvider {
    public String findList(Map<String, Object> param){
        int subShopId = (int)param.get("subShopId");
        String sql = "select * from shop_account where shop_id=#{shopId}\n";
        if(subShopId > 0){
            sql += "and sub_shop_id=#{subShopId}";
        }
        return sql;
    }
}

新增

用@Insert注解進(jìn)行新增操作, 如果需要自動(dòng)賦值自增長(zhǎng)的ID, 需要用到@Options注解

@Insert("insert into shop_account (\n" +
            "  shop_id,\n" +
            "  shop_name,\n" +
            "  sub_shop_id,\n" +
            "  sub_shop_name,\n" +
            "  balance,\n" +
            "  returns,\n" +
            "  create_time,\n" +
            "  update_time,\n" +
            "  recv_account_type,\n" +
            "  recv_value,\n" +
            "  recv_value2,\n" +
            "  check_name\n" +
            ") value (\n" +
            "  #{shopId},\n" +
            "  #{shopName},\n" +
            "  #{subShopId},\n" +
            "  #{subShopName},\n" +
            "  #{balance},\n" +
            "  #{returns},\n" +
            "  now(),\n" +
            "  now(),\n" +
            "  #{recvAccountType},\n" +
            "  #{recvValue},\n" +
            "  #{recvValue2},\n" +
            "  #{checkName}\n" +
            ")")
    @Options(useGeneratedKeys = true, keyProperty = "id", keyColumn = "id")
    void addAccount(ShopAccount account);

其他如更新用@Update注解, 刪除用@Delete注解李根，使用方式同@Insert

當(dāng)Mapper創(chuàng)建完成之后，直接在需要使用的Service中引入即可

    @Autowired
    private ShopAccountMapper shopAccountMapper;