运维开发网

Mybatis传递多个参数进行SQL查询的用法

运维开发网 https://www.qedev.com 2020-04-10 10:59 出处:网络 作者: zifangsky
PS:ibatis3如何传递多个参数有两个方法:一种是使用java.Map,另一种是使用JavaBean。

PS:ibatis3如何传递多个参数有两个方法:一种是使用java.Map,另一种是使用JavaBean。

当只向xxxMapper.xml文件中传递一个参数时,可以简单的用“_parameter”来接收xxxMapper.java传递进来的参数,并代入查询,比如说这样:

(1)xxxMapper.java文件中这样定义:

List<String> selectAllAirportCode(Boolean mapping);

(2)这时在对应的xxxMapper.xml文件中可以使用“_parameter”来接收这个参数:

<select id="selectAllAirportCode" resultType="java.lang.String"
parameterType="java.lang.Boolean">
select DEPARTURE_AIRPORT from USR_AIR_LINE union select
ARRIVAL_AIRPORT from USR_AIR_LINE
<if test="_parameter == true">
union select REL_DEPARTURE_AIRPORT from USR_AIR_LINE union
select
REL_ARRIVAL_AIRPORT from USR_AIR_LINE
</if>
</select>

但是,如果在xxxMapper.java文件中传递进来多个参数,就不能使用上面这种形式来接收参数,这时可以有两种方案来解决这个问题:

一 向xml文件中传递进去一个Map<String, Object>集合,然后xml文件中就可以正常使用Map集合中的各个参数了。

具体实例如下:

(1)xxxMapper.java文件中这样定义:

List<Airline> findAll(Map<String, Object> parms);

(2)在用到上面定义的具体实现类中给Map传参:

public List<Airline> findAll(PageInfo page,Airline airline) {
HashMap<String,Object> params = new HashMap<String,Object>();
params.put("page", page);
params.put("airline", airline);
return airlineMapper.findAll(params);
}

(3)此时对应的xxxMapper.xml文件使用“java.util.Map”来接收这个Map集合:

<sql id="sqlfileders">
<bind name="fileders"
value="#{'id':'ID','departureAirport':'DEPARTURE_AIRPORT','relDepartureAirport':'REL_DEPARTURE_AIRPORT','arrivalAirport':'ARRIVAL_AIRPORT','relArrivalAirport':'REL_ARRIVAL_AIRPORT','popStatus':'POP_STATUS','status':'STATUS','creator':'CREATOR','createTime':'CREATE_TIME'}" />
<bind name="javapropertys"
value="#{'ID':'id','DEPARTURE_AIRPORT':'departureAirport','REL_DEPARTURE_AIRPORT':'relDepartureAirport','ARRIVAL_AIRPORT':'arrivalAirport','REL_ARRIVAL_AIRPORT':'relArrivalAirport','POP_STATUS':'popStatus','STATUS':'status','CREATOR':'creator','CREATE_TIME':'createTime'}" />
</sql>
<select id="findAll" resultMap="BaseResultMap" parameterType="java.util.Map">
<![CDATA[
select x.* from (
select z.*, rownum numbers from (
]]>
select
<include refid="Base_Column_List" />
from
USR_AIR_LINE
<where>
<if test="airline.departureAirport != null">
DEPARTURE_AIRPORT = #{airline.departureAirport}
</if>
<if test="airline.arrivalAirport != null">
and ARRIVAL_AIRPORT=#{airline.arrivalAirport}
</if>
<if test="airline.relDepartureAirport != null">
and REL_DEPARTURE_AIRPORT =
#{airline.relDepartureAirport}
</if>
<if test="airline.relArrivalAirport != null">
and REL_ARRIVAL_AIRPORT = #{airline.relArrivalAirport}
</if>
<if test="airline.popStatus != null">
and POP_STATUS = #{airline.popStatus}
</if>
<if test="airline.status != null">
and STATUS = #{airline.status}
</if>
</where>
<if test="page.sortName != null">
<include refid="sqlfileders" />
<bind name="orderfield" value="#this.fileders[page.sortName]" />
order by ${orderfield} ${page.sortOrder}
</if>
<![CDATA[ ) z where rownum < ]]>
#{page.to}
<![CDATA[ ) x where x.numbers >= ]]>
#{page.from}
</select>

注:上面的实例实现的是分页查询数据。我们可以发现使用Map来传递参数这种形式并不好,因为这样使得在接口中只有一个Map参数,其他人进行维护的时候并不清楚到底需要向这个Map里面传递什么参数进去

二 通过给参数添加@Param注解来解决问题:

(1)给xxxMapper.java文件的方法中的参数添加@Param注解,这个注解中的值对应xml文件中使用到的参数名称:

Airline selectEffectiveAirline(
@Param("departureAirport") String departureAirport,
@Param("arrivalAirport") String arrivalAirport,
@Param("status") BigDecimal status);

(2)此时xxxMapper.xml文件中对应的地方就可以正常使用在@Param注解中对应的值了:

<select id="selectEffectiveAirline" resultMap="BaseResultMap" parameterType="java.util.Map">
select
<include refid="Base_Column_List" />
from
USR_AIR_LINE
<where>
<if test="departureAirport != null">
DEPARTURE_AIRPORT = #{departureAirport}
</if>
<if test="arrivalAirport != null">
and ARRIVAL_AIRPORT=#{arrivalAirport}
</if>
<if test="status != null">
and STATUS = #{status}
</if>
</where>
</select>

注:需要注意的是if条件判断中的参数和在SQL语句中写法是不一样的,if判断中的变量是没有添加#{ }的

下面在单独给大家介绍下通过Mybatis传递多个参数的两个方法

Map传递多个参数

parameterType 可以是别名或完全限定名,map或者java.util.Map,这两个都是可以的

<select id="selectBlogByMap" parameterType="map" resultType="Blog"> 
select t.ID, t.title, t.content 
FROM blog t 
where t.title = #{h_title} 
and t.content =#{h_content} 
</select> 
public void testSelectByMap() { 
SqlSession session = sqlSessionFactory.openSession(); 
Map<String, Object> param=new HashMap<String, Object>(); 
param.put("h_title", "oracle"); 
param.put("h_content", "使用序列"); 
Blog blog = (Blog)session.selectOne("cn.enjoylife.BlogMapper.selectBlogByMap",param); 
session.close(); 
System.out.println("blog title:"+blog.getTitle()); 
} 

通过JavaBean传递多个参数

<select id="selectBlogByBean" parameterType="Blog" resultType="Blog">
select t.ID, t.title, t.content
from blog t
wheret.title = #{title}
and t.content =#{content} 
</select>
public void testSelectByBean() { 
SqlSession session = sqlSessionFactory.openSession(); 
Blog blog=new Blog(); 
blog.setTitle("oracle"); 
blog.setContent("使用序列!"); 
Blog newBlog = (Blog)session.selectOne("cn.enjoylife.BlogMapper.selectBlogByBean",blog); 
session.close(); 
System.out.println("new Blog ID:"+newBlog.getId()); 
}

0

精彩评论

暂无评论...
验证码 换一张
取 消