MyBatis insert 返回主键的方法

原文：http://elf8848.iteye.com/blog/1871843

数据库：SqlServer2005

表结构：

/*==============================================================*/
/* Table: Dic_City                                              */
/*==============================================================*/
create table Dic_City (
   ID                   int                  identity,
   City_Code            varchar(10)          not null,
   Provinces_Code       varchar(20)          not null,
   State_Code           varchar(10)          not null,
   City_Name            varchar(50)          null,
   PY_Code              varchar(50)          null,
   PY_Code_Short        varchar(10)          null,
   Ext1                 varchar(20)          null,
   Ext2                 varchar(20)          null,
   Ext3                 varchar(20)          null,
   Ext4                 varchar(20)          null,
   Ext5                 varchar(20)          null,
   constraint PK_DIC_CITY primary key (ID)
)

MyBatisXML配置，下面两种方式都行

方式1:

<insert id="insert" parameterType="cn.softsea.model.DicCity" >
  <selectKey resultType="java.lang.Integer" keyProperty="id" order="AFTER" >
    SELECT @@IDENTITY
  </selectKey>
  insert into Dic_City (City_Code, Provinces_Code, 
    State_Code, City_Name, PY_Code, 
    PY_Code_Short, Ext1, Ext2, 
    Ext3, Ext4, Ext5)
  values (#{cityCode,jdbcType=VARCHAR}, #{provincesCode,jdbcType=VARCHAR}, 
    #{stateCode,jdbcType=VARCHAR}, #{cityName,jdbcType=VARCHAR}, #{pyCode,jdbcType=VARCHAR}, 
    #{pyCodeShort,jdbcType=VARCHAR}, #{ext1,jdbcType=VARCHAR}, #{ext2,jdbcType=VARCHAR}, 
    #{ext3,jdbcType=VARCHAR}, #{ext4,jdbcType=VARCHAR}, #{ext5,jdbcType=VARCHAR})
</insert>

方式2:

<insert id="insert" parameterType="cn.softsea.model.DicCity" useGeneratedKeys="true" keyProperty="id">
  insert into Dic_City (City_Code, Provinces_Code, 
    State_Code, City_Name, PY_Code, 
    PY_Code_Short, Ext1, Ext2, 
    Ext3, Ext4, Ext5)
  values (#{cityCode,jdbcType=VARCHAR}, #{provincesCode,jdbcType=VARCHAR}, 
    #{stateCode,jdbcType=VARCHAR}, #{cityName,jdbcType=VARCHAR}, #{pyCode,jdbcType=VARCHAR}, 
    #{pyCodeShort,jdbcType=VARCHAR}, #{ext1,jdbcType=VARCHAR}, #{ext2,jdbcType=VARCHAR}, 
    #{ext3,jdbcType=VARCHAR}, #{ext4,jdbcType=VARCHAR}, #{ext5,jdbcType=VARCHAR})
</insert>

调用Mapper返回主键：

//生成新对象用于插入
DicCity city = new DicCity();
city.setCityCode("330100");
city.setCityName("杭州市");

//获取mapper对象
DicCityMapper cityMapper = (DicCityMapper) SpringContextUtil.getBean("dicCityMapper");

int row = cityMapper.insert(city);    //insrt不再返回主键，只返回响应行数，这点和ibatis不同了

System.out.println("响应的行数："+row);
//取得自增的标识列 ID的值
System.out.println("新插入的数据的ID："+city.getId());

====================

如果使用mybatis.generator来生成DAO层的话，generatorConfig.xml中要使用：

<generatedKeycolumn="id"sqlStatement="MySql"identity="true"/>